The Training Support Column MkII

[tim290280]

Even JornT won't have a problem with this paper.

I've been banging on for years about muscle imbalances at the shoulder. Having experienced the beginings of imbalance problems myself I can say that this is not something to dismiss. Basically this is another piece of evidence saying that people lifting weights just aren't getting it right. We do need to be carefull about recruiting the correct muscles and making sure there are prehab exercises and balance to our programs.

Shoulder Joint and Muscle Characteristics in the Recreational Weight Training Population.

Journal of Strength & Conditioning Research. 23(1):148-157, January 2009.
Kolber, Morey J; Beekhuizen, Kristina S; Cheng, Ming-Shun S; Hellman, Madeleine A
Abstract:
Kolber, MJ, Beekhuizen, KS, Cheng, MS, and Hellman, MA. Shoulder joint and muscle characteristics in the recreational weight training population. J Strength Cond Res 23(1): 148-157, 2009-Shoulder disorders attributed to weight training are well documented in the literature; however, a paucity of evidence-based research exists to describe risk factors inherent to participation. Shoulder joint and muscle characteristics in the recreational weight training (RWT) population were investigated to determine specific risk-related adaptations that may occur from participation. Ninety participants, men between the ages of 19 and 47 (mean age 28.9), including 60 individuals who participated in upper-extremity RWT and 30 controls with no record of RWT participation, were recruited. Active range of motion (AROM), posterior shoulder tightness (PST), body weight-adjusted strength values, and agonist/antagonist strength ratios were compared between the RWT participants and the control group. Statistical analysis identified significant differences (p < 0.001) between the groups when analyzing shoulder mobility. The RWT participants had decreased mobility when compared with the control group for all AROM measurements except external rotation, which was greater. Strength ratios were significantly greater in the RWT group when compared with the control group (p <= 0.001), implying agonist/antagonist muscle imbalances. The findings of this investigation suggest that RWT participants are predisposed to strength and mobility imbalances as a result of training. The imbalances identified have been associated with shoulder disorders in the general and athletic population; thus, these imbalances may place RWT participants at risk for injury. Common training patterns are biased toward large muscle groups such as the pectorals and deltoids but neglect muscles responsible for stabilization such as the external rotators and lower trapezius. Exercise selection that mitigates strength and mobility imbalances may serve to prevent injury in this population. Clinicians and strength and conditioning professionals should consider the biomechanical stresses and adaptations associated with RWT when prescribing upper-extremity exercises.

So make sure that you are hitting the external rotators and the lower trapezius.

 

[tim290280]

Another nail in the coffin for stance width changing muscle recruitment in the thigh.

The only thing left to do is to stop letting personal trainers and BBers give people advice and this myth may just die!

The Effect of Stance Width on the Electromyographical Activity of Eight Superficial Thigh Muscles During Back Squat With Different Bar Loads.

Journal of Strength & Conditioning Research. 23(1):246-250, January 2009.
Paoli, Antonio 1; Marcolin, Giuseppe 1; Petrone, Nicola 2
Abstract:
Paoli, A, Marcolin, G, and Petrone, N. The effect of stance width on the electromyographical activity of eight superficial thigh muscles during back squat with different bar loads. J Strength Cond Res 23(1): 246-250, 2009-Many strength trainers believe that varying the stance width during the back squat can target specific muscles of the thigh. The aim of the present work was to test this theory measuring the activation of 8 thigh muscles while performing back squats at 3 stance widths and with 3 different bar loads. Six experienced lifters performed 3 sets of 10 repetitions of squats, each one with a different stance width, using 3 resistances: no load, 30% of 1-repetition maximum (1RM), and 70% 1RM. Sets were separated by 6 minutes of rest. Electromyographic (EMG) surface electrodes were placed on the vastus medialis, vastus lateralis, rectus femoris, semitendinosus, biceps femoris, gluteus maximus, gluteus medium, and adductor maior. Analysis of variance and Scheffe post hoc tests indicated a significant difference in EMG activity only for the gluteus maximus; in particular, there was a higher electrical activity of this muscle when back squats were performed at the maximum stance widths at 0 and 70% 1RM. There were no significant differences concerning the EMG activity of the other analyzed muscles. These findings suggest that a large width is necessary for a greater activation of the gluteus maximus during back squats.

And this one is YAY Front Squats!

A Biomechanical Comparison of Back and Front Squats in Healthy Trained Individuals.

Original Research

Journal of Strength & Conditioning Research. 23(1):284-292, January 2009.
Gullett, Jonathan C; Tillman, Mark D; Gutierrez, Gregory M; Chow, John W
Abstract:
Gullett, JC, Tillman, MD, Gutierrez, GM, and Chow, JW. A biomechanical comparison of back and front squats in healthy trained individuals. J Strength Cond Res 23(1): 284-292, 2008-The strength and stability of the knee plays an integral role in athletics and activities of daily living. A better understanding of knee joint biomechanics while performing variations of the squat would be useful in rehabilitation and exercise prescription. We quantified and compared tibiofemoral joint kinetics as well as muscle activity while executing front and back squats. Because of the inherent change in the position of the center of mass of the bar between the front and back squat lifts, we hypothesized that the back squat would result in increased loads on the knee joint and that the front squat would result in increased knee extensor and decreased back extensor muscle activity. A crossover study design was used. To assess the net force and torque placed on the knee and muscle activation levels, a combination of video and force data, as well as surface electromyographic data, were collected from 15 healthy trained individuals. The back squat resulted in significantly higher compressive forces and knee extensor moments than the front squat. Shear forces at the knee were small in magnitude, posteriorly directed, and did not vary between the squat variations. Although bar position did not influence muscle activity, muscle activation during the ascending phase was significantly greater than during the descending phase. The front squat was as effective as the back squat in terms of overall muscle recruitment, with significantly less compressive forces and extensor moments. The results suggest that front squats may be advantageous compared with back squats for individuals with knee problems such as meniscus tears, and for long-term joint health.

Main reason I'm posting these is my journal updates just arrived.......

 

[tim290280]

Interesting stuff to look at. Inverted rows actually activate the back more but obviously offer lower loading.

Journal of Strength and Conditioning Research:Volume 23(2)March 2009pp 350-358
Comparison of Different Rowing Exercises: Trunk Muscle Activation and Lumbar Spine Motion, Load, and Stiffness

Fenwick, Chad M J; Brown, Stephen H M; McGill, Stuart M

Abstract

Fenwick, CMJ, Brown, SHM, and McGill, SM. Comparison of different rowing exercises: trunk muscle activation and lumbar spine motion, load, and stiffness. J Strength Cond Res 23(2): 350-358, 2009-The objective of this study was to investigate 3 different rowing exercises and quantify the muscle activation of the torso and the hip musculature, together with the corresponding spinal loading and stiffness. Seven healthy men from a university population were instrumented to obtain surface electromyography of selected trunk and hip muscles and to obtain spine position using an electromagnetic spine position sensor, together with video analysis to calculate joint moments. The 3 rowing exercises investigated were the inverted row, standing bent-over row, and standing 1-armed cable row. The inverted row elicited the highest activation of the latissimus dorsi muscles, upper-back, and hip extensor muscles. The lower activation of the lumbar erector spinae muscles during the inverted row corresponded to the lower spine load measured. The standing bent-over row produced large activation symmetrically across the back, but it produced the largest lumbar spine load. The 1-armed cable row challenged the torsional capabilities of the trunk musculature. Some core exercises may be better for rehabilitation (e.g., having the training goals of modest muscle activation with low spine load), whereas other exercises may be better for athletic training (e.g., resulting in higher muscle activation and larger spine load). When prescribing core exercises, those wishing to spare the low back may choose the inverted row, given the lowest spine load exercise. The standing bent-over row elicited large muscle activation symmetrically from the upper to lower back; it induced larger spine loads but also, not surprisingly, the highest spine stiffness. If torsional endurance or strength is the training goal, the 1-armed cable row might be considered.

 

[tim290280]

Dynamic still the best prior to exercise.

Journal of Strength and Conditioning Research:Volume 23(2)March 2009pp 507-512
Effects of Dynamic and Static Stretching on Vertical Jump Performance and Electromyographic Activity

Hough, Paul A1; Ross, Emma Z2; Howatson, Glyn1

Abstract

Hough, PA, Ross, EZ, and Howatson, G. Effects of dynamic and static stretching on vertical jump performance and electromyographic activity. J Strength Cond Res 23(2): 507-512, 2009-The results of previous research have demonstrated that static stretching (SS) can reduce muscular performance and that dynamic stretching (DS) can enhance muscular performance. The purpose of this study was to assess the effects of SS and DS on vertical jump (VJ) performance and electromyographic (EMG) activity of the m. vastus medialis. Eleven healthy men (age 21 ± 2 years) took part in 3 conditions (no stretching [NS], SS, and DS), on separate occasions in a randomized, crossover design. During each condition, measurements of VJ height and EMG activity during the VJ were recorded. A repeated-measures analysis of variance and post hoc analysis indicated that VJ height was significantly less (4.19 ± 4.47%) after SS than NS (p < 0.05) and significantly greater (9.44 ± 4.25%) in DS than SS (p < 0.05). There was significantly greater EMG amplitude in the DS compared with the SS (p < 0.05). The results demonstrated that SS has a negative influence on VJ performance, whereas DS has a positive impact. Increased VJ performance after DS may be attributed to postactivation potentiation, whereas the reduction in VJ performance after SS may be attributable to neurological impairment and a possible alteration in the viscoelastic properties of the muscular tendon unit (MTU). This investigation provides some physiological basis for the inclusion of DS and exclusion of SS in preparation for activities requiring jumping performance.

Yay HIIT.

Journal of Strength and Conditioning Research:Volume 23(2)March 2009pp 587-592
The Effect of a High-Intensity Interval Training Program on High-Density Lipoprotein Cholesterol in Young Men

Musa, Danladi I1; Adeniran, Samuel A2; Dikko, A U3; Sayers, Stephen P4

Abstract

Musa, DI, Adeniran, SA, Dikko, AU, and Sayers, SP. The effect of a high-intensity interval training program on high-density lipoprotein cholesterol in young men. J Strength Cond Res 23(2): 587-592, 2009-This study examined the impact of an 8-week program of high-intensity interval training on high-density lipoprotein cholesterol (HDL-C), total cholesterol (TC), and the atherogenic index (TC/HDL-C) in 36 untrained men ages 21-36 years. Participants were randomly assigned to an interval training group (n = 20) or a control group (n = 16). Participants in the experimental group performed 3.2 km of interval running (1:1 work:rest ratio) 3 times a week for 8 weeks at an intensity of 90% of maximal heart rate (∼423 kcal per session). Results indicated significant pre- to posttraining changes in HDL-C (1.1 vs. 1.3 mmol·L-1, p < 0.0001) and TC/HDL-C (3.8 vs. 3.1, p < 0.0001) but no significant changes in TC (3.9 vs. 3.8 mmol·L-1, p > 0.05) with interval training. It was concluded that an 8-week program of high-intensity interval training is effective in eliciting favorable changes in HDL-C and TC/HDL-C but not TC in young adult men with normal TC levels. Our findings support the recommendations of high-intensity interval training as an alternative mode of exercise to improve blood lipid profiles for individuals with acceptable physical fitness levels.

 

[tim290280]

Why couldn't them have done this research before I did my knee :angrydude:

A Randomized Controlled Trial to Prevent Noncontact Anterior Cruciate Ligament Injury in Female Collegiate Soccer Players

Background: Neuromuscular and proprioceptive training programs can decrease noncontact anterior cruciate ligament injuries; however, they may be difficult to implement within an entire team or the community at large.
Hypothesis: A simple on-field alternative warm-up program can reduce noncontact ACL injuries.
Study Design: Randomized controlled trial (clustered); Level of evidence, 1.
Methods: Participating National Collegiate Athletic Association Division I women’s soccer teams were assigned randomly to intervention or control groups. Intervention teams were asked to perform the program 3 times per week during the fall 2002 season. All teams reported athletes’ participation in games and practices and any knee injuries. Injury rates were calculated based on athlete exposures, expressed as rate per 1000 athlete exposures. A z statistic was used for rate ratio comparisons.
Results: Sixty-one teams with 1435 athletes completed the study (852 control athletes; 583 intervention). The overall anterior cruciate ligament injury rate among intervention athletes was 1.7 times less than in control athletes (0.199 vs 0.340; P = .198; 41% decrease). Noncontact anterior cruciate ligament injury rate among intervention athletes was 3.3 times less than in control athletes (0.057 vs 0.189; P = .066; 70% decrease). No anterior cruciate ligament injuries occurred among intervention athletes during practice versus 6 among control athletes (P = .014). Game-related noncontact anterior cruciate ligament injury rates in intervention athletes were reduced by more than half (0.233 vs 0.564; P = .218). Intervention athletes with a history of anterior cruciate ligament injury were significantly less likely to suffer another anterior cruciate ligament injury compared with control athletes with a similar history (P = .046 for noncontact injuries).
Conclusion: This program, which focuses on neuromuscular control, appears to reduce the risk of anterior cruciate ligament injuries in collegiate female soccer players, especially those with a history of anterior cruciate ligament injury.

 

[tim290280]

I've Invented a Finisher for Legs

Ok this evening I made up a great little routine for finishing off the legs.

What you do is unload the bar you have just been using for squats, deadlifts or whatever.

Ok, so far so simple.

The trick is that each plate you pull off you press overhead and then squat for a set of 8-10 reps. Put the plate down and then pull the next plate and repeat.

The rest you get between sets is from walking from one end of the bar to the other to remove a plate. No more no less.

After trying it out tell me how much you hate finishers

 

[Natzo]

^^^^

:inouteek:

 

[tim290280]

Maximal Anaerobic Power Test in Athletes of Different Sport Disciplines.

Journal of Strength & Conditioning Research. 23(3):751-755, May 2009.
Popadic Gacesa, Jelena Z; Barak, Otto F; Grujic, Nikola G

Abstract:
The aim of this study was to investigate the values of anaerobic energetic capacity variables in athletes engaged in different sport disciplines and to compare them in relation to specific demands of each sport. Wingate anaerobic tests were conducted on 145 elite athletes (14 boxers, 17 wrestlers, 27 hockey players, 23 volleyball players, 20 handball players, 25 basketball players, and 19 soccer players). Three variables were measured as markers of anaerobic capacity: peak power, mean power, and explosive power. The highest values of peak power were measured in volleyball 11.71 +/- 1.56 W[middle dot]kg-1 and basketball players 10.69 +/- 1.67 W[middle dot]kg-1, and the difference was significant compared with the other athletes (p <= 0.05). The lowest value of peak power (8.58 +/- 1.56 W[middle dot]kg-1) was registered in handball players. The mean power variable showed a similar distribution as peak power among groups. The highest values of explosive power were also registered in volleyball 1.75 +/- 0.33 W[middle dot]s-1[middle dot]kg-1 and basketball players 1.64 +/- 0.35 W[middle dot]s-1[middle dot]kg-1, but there was no significant difference in values between volleyball players and wrestlers, between boxers and wrestlers, between boxers and basketball players, and between volleyball and hockey players (p > 0.05). The measured results show the influence of anaerobic capacity in different sports and the referral values of these variables for the elite male athletes. Explosive power presented a new dimension of anaerobic power, i.e., how fast maximal energy for power development can be obtained, and its values are high in all sports activities that demand explosiveness and fast maximal energy production. Coaches or other experts in the field could, in the future, find useful to follow and improve, through training process, one of the variables that is most informative for that sport.

So wrestlers and boxers suck more than volleyball players

 

[tim290280]

Don't use more than a couple of kilos in resisted running unless you want to mess up your running style.

Influence of Towing Force Magnitude on the Kinematics of Supramaximal Sprinting.

Original Research
Journal of Strength & Conditioning Research. 23(4):1162-1168, July 2009.
Clark, David A 1; Sabick, Michelle B 1,2; Pfeiffer, Ronald P 1,3; Kuhlman, Seth M 1; Knigge, Nicole A 1; Shea, Kevin G 4

Abstract:
Clark, DA, Sabick, MB, Pfeiffer, RP, Kuhlman, SM, Knigge, NA, and Shea, KG. Influence of towing force magnitude on the kinematics of supramaximal sprinting. J Strength Cond Res 23(4): 1162-1168, 2009-The purpose of this study was to determine the influence of towing force magnitude on the kinematics of supramaximal sprinting. Ten high school and college-age track and field athletes (6 men, 4 women) ran 60-m maximal sprints under 5 different conditions: Nontowed, Tow A (2.0% body weight [BW]), Tow B (2.8% BW), Tow C (3.8% BW), and Tow D (4.7% BW). Three-dimensional kinematics of a 4-segment model of the right side of the body were collected starting at the 35-m point of the trial using high-speed (250 Hz) optical cameras. Significant differences (p < 0.05) were observed in stride length and horizontal velocity of the center of mass during Tow C and Tow D. For Tow D, a significant increase (p = 0.046) in the distance from the center of mass to the foot at touchdown was also observed. Contact time decreased significantly in all towing conditions (p < 0.01), whereas stride rate increased only slightly (<2.0%) under towed conditions. There were no significant changes in joint or segment angles at touchdown, with the exception of a significant decrease (p = 0.044) in the flexion/extension angle at the hip during the Tow D condition. We conclude that towing force magnitude does influence the kinematics of supramaximal running and that potentially negative training effects may arise from towing individuals with a force in excess of 3.8% BW. Therefore, we suggest that coaches and practitioners adjust towing force magnitude for each individual and avoid using towing forces in excess of 3.8% of the athlete's BW.

Strongman isn't great for your back but it is great at getting your body to work together. Who'd have thought that you could lift more than your joints allow?! This is just a great read:

Comparison of Different Strongman Events: Trunk Muscle Activation and Lumbar Spine Motion, Load, and Stiffness.

Original Research
Journal of Strength & Conditioning Research. 23(4):1148-1161, July 2009.
McGill, Stuart M 1; McDermott, Art 2; Fenwick, Chad MJ 1

Abstract:
McGill, SM, McDermott, A, and Fenwick, CMJ. Comparison of different strongman events: trunk muscle activation and lumbar spine motion, load, and stiffness. J Strength Cond Res 23(4): 1148-1161, 2009-Strongman events are attracting more interest as training exercises because of their unique demands. Further, strongman competitors sustain specific injuries, particularly to the back. Muscle electromyographic data from various torso and hip muscles, together with kinematic measures, were input to an anatomically detailed model of the torso to estimate back load, low-back stiffness, and hip torque. Events included the farmer's walk, super yoke, Atlas stone lift, suitcase carry, keg walk, tire flip, and log lift. The results document the unique demands of these whole-body events and, in particular, the demands on the back and torso. For example, the very large moments required at the hip for abduction when performing a yoke walk exceed the strength capability of the hip. Here, muscles such as quadratus lumborum made up for the strength deficit by generating frontal plane torque to support the torso/pelvis. In this way, the stiffened torso acts as a source of strength to allow joints with insufficient strength to be buttressed, resulting in successful performance. Timing of muscle activation patterns in events such as the Atlas stone lift demonstrated the need to integrate the hip extensors before the back extensors. Even so, because of the awkward shape of the stone, the protective neutral spine posture was impossible to achieve, resulting in substantial loading on the back that is placed in a weakened posture. Unexpectedly, the super yoke carry resulted in the highest loads on the spine. This was attributed to the weight of the yoke coupled with the massive torso muscle cocontraction, which produced torso stiffness to ensure spine stability together with buttressing the abduction strength insufficiency of the hips. Strongman events clearly challenge the strength of the body linkage, together with the stabilizing system, in a different way than traditional approaches. The carrying events challenged different abilities than the lifting events, suggesting that loaded carrying would enhance traditional lifting-based strength programs. This analysis also documented the technique components of successful, joint-sparing, strongman event strategies.

I can already hear the from powerlifters everywhere:

Effects of the Bench Shirt on Sagittal Bar Path.

Original Research
Journal of Strength & Conditioning Research. 23(4):1125-1128, July 2009.
Silver, Tobin 1; Fortenbaugh, Dave 2; Williams, Ryan 3

Abstract:
Silver, T, Fortenbaugh, D, and Williams, R. Effects of the bench shirt on sagittal bar path. J Strength Cond Res 23(4): 1125-1128, 2009-Powerlifting, like many sports, uses specialized equipment to enhance performance and decrease the chance of injury. The purpose of this exploratory study was to determine whether wearing a bench press shirt would alter the natural mechanics of the bench press, causing a more efficient lift when pressing the same weight as without the bench shirt. Participants (n = 5) completed 2 series of 1-repetition maximum (1RM) bench press tests, with 1 week of rest in between 1 series without the bench shirt (no-shirt), and 1 series with a bench shirt (bench shirt). Results revealed that the vertical bar path ranges were significantly less in the bench shirt condition (35.7 +/- 4.8 cm) compared with the no-shirt condition (40.2 +/- 7.0 cm) (p < 0.05). Significant differences were found between the bar's optimal (81.4 +/- 14.2 cm) and observed (96.7 +/- 19.1 cm) total distances traveled in the no-shirt condition (p < 0.01), but no significant differences were found between the bar's optimal (71.6 +/- 12.7 cm) and observed (86.3 +/- 10.5 cm) total distances traveled in the bench shirt condition. These findings suggest that the bar path in bench shirt trials is more efficient and consistent than in the no-shirt trials. This pattern demonstrates that a bench shirt can improve load capacity. It is also possible that the bench shirt decreases the forces that act on the shoulder for a given weight and, thus, may decrease the risk of injury.

Yet another study to show that body fat estimations, especially skin folds, are just so inaccurate. Really only useful to show progress.

Anthropometric Estimations of Percent Body Fat in NCAA Division I Female Athletes: A 4-Compartment Model Validation.

Original Research
Journal of Strength & Conditioning Research. 23(4):1068-1076, July 2009.
Moon, Jordan R 1; Tobkin, Sarah E 1; Smith, Abbie E 1; Lockwood, Chris M 1; Walter, Ashley A 2; Cramer, Joel T 2; Beck, Travis W 2; Stout, Jeffrey R 1

Abstract:
Moon, JR, Tobkin, SE, Smith, AE, Lockwood, CM, Walter, AA, Cramer, JT, Beck, TW, and Stout, JR. Anthropometric estimations of percent body fat in NCAA Division I female athletes: A 4-compartment model validation. J Strength Cond Res 23(4): 1068-1076, 2009-Anthropometric equations, based on 2-compartment models, have been routinely used to estimate body composition in female college athletes; however, these equations are not without error. In an attempt to decrease the error associated with anthropometric equations, updated equations were developed using multiple-compartment models, although the validity of these equations has not yet been established. The purpose of the current investigation was to determine the validity of the updated anthropometric equations and compare them with previously validated generalized equations for estimating percent fat (%fat) in female athletes. Twenty-nine white female NCAA Division I athletes (20 +/- 1 years) volunteered to have their %fat estimated using anthropometric measurements. Skinfold equations included generalized and updated equations and a height and weight-based equation. %fat values were compared with a criterion 4-compartment model. All equations produced low total error (TE) (<=3.38%fat) and SEE values (<=2.97%fat) and high r values (r >= 0.78). The 2 updated skinfold equations produced the highest constant error (CE) values, but the tightest limits of agreement (<= -1.58 +/- 4.86%fat; CE +/- 2SD) compared with the 3 generalized Jackson et al. equations (<=0.92 +/- 5.34%fat), whereas the limits of agreement for the height and weight-based equation (+/- 6.00%fat) were the widest. Compared with the updated skinfold equations, the generalized Jackson et al. skinfold equations produced nearly identical TE values. Results suggest that the updated skinfold equations are valid but not superior to the generalized Jackson et al. equations, and the height and weight-based equation of Fornetti et al. is not recommended due to the large individual error in this population. Additionally, more than 3 skinfold sites did not improve %fat values. Therefore, the Jackson et al. sum of 3 skinfold equation is the suggested skinfold equation in the white female NCAA Division I athletes.

 

[Clint]

great reads Tim. I agree 100% about the calipers, but I do like using them for tracking benefits.

 

[tim290280]

great reads Tim. I agree 100% about the calipers, but I do like using them for tracking benefits.

I think that is the benefit of calipers, you can just measure consistently over time and track that you have been losing fat. I think I posted something one time about how the three site test was actually more accurate than the seven site.

 

[tim290280]

I've just read this interesting article about speed development. It states a measure of how much additional force you need to produce for every bit of weight gained for running.

The most important factor to work on in order to increase your start, acceleration, and maximum speed is to increase “ground contact forces.” These forces are determined by the speed-strength of muscles pushing action away from the ground in the start as well as by acceleration, maximum speed, and speed endurance. The athlete’s speed-strength to body weight ratio comes into play here (1). Ground contact forces determine the maximum speed an athlete can reach (1). For each pound of body weight, 2.15 additional pounds of ground contact force are needed just to maintain an athlete’s starting, acceleration, and maximum speed (1). So, if an athlete packs on an additional ten pounds of mass, he will need an additional 21.5 pounds of ground contact force, regardless of the composition of the added mass.

I'd actually like a better reference than the one that was used (a certification manual for a coaching course). Has anyone seen the original research cited?

 

[tim290280]

This is the paper that shows that Front Squats are better. Enjoy Bulky

A Biomechanical Comparison of Back and Front Squats in Healthy Trained Individuals
Gullett, Jonathan C; Tillman, Mark D; Gutierrez, Gregory M; Chow, John W

Abstract
Gullett, JC, Tillman, MD, Gutierrez, GM, and Chow, JW. A biomechanical comparison of back and front squats in healthy trained individuals. J Strength Cond Res 23(1): 284-292, 2008-The strength and stability of the knee plays an integral role in athletics and activities of daily living. A better understanding of knee joint biomechanics while performing variations of the squat would be useful in rehabilitation and exercise prescription. We quantified and compared tibiofemoral joint kinetics as well as muscle activity while executing front and back squats. Because of the inherent change in the position of the center of mass of the bar between the front and back squat lifts, we hypothesized that the back squat would result in increased loads on the knee joint and that the front squat would result in increased knee extensor and decreased back extensor muscle activity. A crossover study design was used. To assess the net force and torque placed on the knee and muscle activation levels, a combination of video and force data, as well as surface electromyographic data, were collected from 15 healthy trained individuals. The back squat resulted in significantly higher compressive forces and knee extensor moments than the front squat. Shear forces at the knee were small in magnitude, posteriorly directed, and did not vary between the squat variations. Although bar position did not influence muscle activity, muscle activation during the ascending phase was significantly greater than during the descending phase. The front squat was as effective as the back squat in terms of overall muscle recruitment, with significantly less compressive forces and extensor moments. The results suggest that front squats may be advantageous compared with back squats for individuals with knee problems such as meniscus tears, and for long-term joint health.

I still like doing back squats, but in any given year should probably spend more time doing other types of lower loading squats like front, bulgarian and split squats.


Also a paper on the effectiveness of belts. Yep they work. But have a look at what data they decided to present. Their significant results were for loads of +90% of 1RM. So belts really only have a place on heavy singles and doubles (unless you get more reps with your 90%).

The effectiveness of weight-belts during the squat exercise
LANDER, JEFFREY E.; SIMONTON, R. LESLIE; GIACOBBE, JOEL K. F.

Abstract
The purpose of this study was to examine the effectiveness of weight-belts during the performance of the parallel squat exercise. Six subjects were filmed (40 fps) as they performed three trials at each of three belt conditions (NB, none; LB, light; HB, heavy) in random order and three load conditions (70, 80, 90% 1RM (one repetition maximum)) in increasing order. The parameters examined were collected and interfaced to a computer via an analog-to-digital (A/D) converter: ground reaction forces, intra-abdominal pressure (IAP), and EMG for the rectus abdominus (RA), external oblique (EO), and erector spinae (ES) muscles. Most differences were observed during the 90% 1RM condition, and only they are presented in this paper. Maximum IAP values were always greater (P < 0.05) for the weight-belt conditions (LB, 29.2; HB, 29.1 &gt NB, 26.8 kPa). Similar results were observed for the mean IAP. The integrated EMG (iEMG) activity of the muscles and adjusted mean values for back compressive force and back muscle force followed a similar but opposite pattern, with NB being the greatest. ES mEMG/(L5/S1) values for HB (18.1%) were the least, followed by LB (20.01%) and NB (22.3%). Few differences were observed between belt types. These data suggest that a weight-belt can aid in supporting the trunk by increasing IAP.

 

[Bulkboy]

sweet article. well this defends my transition to fronties for sure. thanks alot for the effort tim

 

[PrinceVegeta]

^^ fronties are for weaklings...

JK bulky, i understand the reasoning, might think twice before i do the cycle..fronties or backies?

 

[tim290280]

^^ I think the message is not to overuse the back squat. Your spine needs some time off from heavy forces.

So I'd say deadlifts are in this category too. They have to be dropped out occassionally.

So hitting legs really needs to be about strength and not just heavy poundage on the bar. You can get the same effect with a split squat that you can with a back squat with half the weight on the bar.

 

[tim290280]

I was watching a CrossFit video today and was both impressed and appalled at the same time. There was no way that I would have been able to do one of their CrossFit Games workouts with any decent weight. There was also no way I would have been able to do it with anything other than the crappy form they used to complete the lifts.

Which brings me to this bit of research. Strength endurance is best to be improved by increasing your max strength. This research shows that if you get your max up to the point were your endurance weight will be <40% of that max then you'll take those CrossFitters to the cleaners :gaysign:

The Influence of Strength and Power on Muscle Endurance Test Performance.

Original Research
Journal of Strength & Conditioning Research. 23(5):1482-1488, August 2009.
Naclerio, Fernando J 1; Colado, Juan C 2; Rhea, Matthew R 3; Bunker, Derek 3; Triplett, N Travis 4

Abstract:
Naclerio, FJ, Colado, JC, Rhea, MR, Bunker, D, and Triplett, NT. The influence of strength and power on muscle endurance test performance. J Strength Cond Res 23(5): 1482-1488, 2009-The aim of this study was to determine the importance of muscular strength and power on a muscular endurance performance test. Fourteen firefighter recruits performed a progressive resistance test (PRT) followed by a specific maximum repetition test (MRT40) on the bench press exercise with measurements of power, strength, and muscular endurance. Comparisons were then made to examine relationships between the 3 muscular fitness variables. The results, expressed in absolute form and related to body weight, indicate that the performance in the MRT40 is significantly related (p <= 0.05) to body weight (r = 0.78), 1 repetition maximum (1RM) (r = 0.83), maximal power (Pmax) during the PRT (r = 0.71), Pmax produced with 40 kg in the PRT (r = 0.64), and the average power and force applied during all repetitions in the MRT40 (r = 0.78 and r = -0.64, respectively). The load that expressed the maximal average power during the PRT was 47.6 +/- 9.0% of the 1RM and did not show any significant relationship with 1RM nor performance in MRT40. It was concluded that performance in this specific upper body endurance test depends on several variables, among which maximum strength, body weight, and maximum absolute power are the most important. As the ability to repeatedly apply submaximal force is a requirement of firefighters, and other occupations/sports, the current research suggests that the initial goal of a training program to enhance muscular endurance should be to increase maximum strength to a point that the specific load being lifted during repeated actions is less than 40% of the individuals' 1RM. Subsequent training should then focus on maintaining maximal strength levels and improving local muscular endurance in the specific task.

 

[tim290280]

Chains good for speed work; thanks for being 10yrs behind.

Effect of Kinetically Altering a Repetition via the Use of Chain Resistance on Velocity During the Bench Press.


Journal of Strength & Conditioning Research. 23(7):1941-1946, October 2009.
Baker, Daniel G; Newton, Robert U

Abstract:
Baker, DG and Newton, RU. Effect of kinetically altering a repetition via the use of chain resistance on velocity during the bench press. J Strength Cond Res 23(7): 1941-1946, 2009-It is theorized that the force and velocity profile of a repetition performed during a standard barbell exercise may be altered by substituting suspended chains for some portion of the total resistance. The purpose of this study was to document the alterations in lifting velocity that occur when the bench press exercise is performed as standard (BP) or with the substitution of resistance via chains draped over the barbell (BP+CH). Thirteen professional rugby league players participated in this study as part of their usual training program. Each subject performed 2 sets of 3 repetitions under the following conditions: The BP+CH condition, where the barbell resistance of 60% 1RM (repetition maximum) was supplemented by 17.5-kg in chains draped over the barbell (total resistance was about 75% 1RM), and the BP condition, where the total resistance was the same but was constituted in the form of standard barbell weights. The BP+CH condition resulted in increases in mean and peak concentric lifting velocities of around 10% in both sets as compared to both BP sets. Eccentric peak velocities were more varied in response, but generally the addition of chain resistance could be said to allow for increased velocities. The result may be partially explained by the eccentric unloading that occurs as the chain links furl upon the floor in the latter stages of the eccentric range. This eccentric unloading precipitates a more rapid stretch-shorten cycle (SSC) transition and possibly a within-repetition postactivation potentiation (PAP) that allows the subject to utilize faster lifting velocities in the initial concentric portion, which flow through to the remainder of the concentric phase. Therefore the use of chains appears warranted when athletes need to lift heavy resistances explosively.

They didn't measure enough muscles for my liking, but shows the front pull is better:

Electromyographic Analysis of Three Different Types of Lat Pull-Down.

Journal of Strength & Conditioning Research. 23(7):2033-2038, October 2009.
Sperandei, Sandro 1; Barros, Marcos A P 2; Silveira-Junior, Paulo C S 2; Oliveira, Carlos G 3,4

Abstract:
Sperandei, S, Barros, MAP, Silveira-Junior, PCS, and Oliveira, CG. Electromyographic analysis of three different types of lat pull-down. J Strength Cond Res 23(7): 2033-2038, 2009-The purpose of this work was to evaluate the activity of the primary motor muscles during the performance of 3 lat pull-down techniques through surface electromyography (EMG). Twenty-four trained adult men performed 5 repetitions of behind-the-neck (BNL), front-of-the-neck (FNL), and V-bar exercises at 80% of 1 repetition maximum. For each technique, the root mean square from the EMG signal was registered from the pectoralis major (PM), latissimus dorsi (LD), posterior deltoid (PD), and biceps brachii (BB) and further normalized in respect to that which presented the highest value of all the techniques. A series of two-way repeated measures analysis of variance was used to compare the results, with Tukey-Kramer as the post hoc test and [alpha] = 0.05. During the concentric phase, PM value showed the FNL to be significantly higher than V-bar/BNL and V-bar higher than BNL. During the eccentric phase, FNL/V-bar was higher than BNL. For LD, there was no difference between techniques. PD presented BNL higher than FNL/V-bar and FNL higher than V-bar in the concentric phase and BNL higher than V-bar in the eccentric phase. BB exhibited BNL higher than V-bar/FNL and V-bar higher than FNL in both concentric and eccentric phases. Considering the main objectives of lat pull-down, we concluded that FNL is the better choice, whereas BNL is not a good lat pull-down technique and should be avoided. V-bar could be used as an alternative.

Fat burning zone is such a load of wank. This shows it is only useful in a clinical setting:

Quantifying Differences in the "Fat Burning" Zone and the Aerobic Zone: Implications For Training.

Journal of Strength & Conditioning Research. 23(7):2090-2095, October 2009.
Carey, Daniel G

Abstract:
Carey, DG. Quantifying differences in the "fat burning" zone and the aerobic zone: implications for training. J Strength Cond Res 23(7): 2090-2095, 2009-The primary objective of this study was to examine the relationship of the "fat burning" and aerobic zones. Subjects consisted of 36 relatively fit runners (20 male, 16 female) who completed a maximal exercise test to exhaustion on a motor-driven treadmill. The lower and upper limit of the "fat burning" zone was visually assessed by examining each individual graph. Maximal fat oxidation (MFO) was determined to be that point during the test at which fat metabolism in fat calories per minute peaked. The lower limit of the aerobic zone was assessed as 50% of heart rate reserve, whereas the upper limit was set at anaerobic threshold. Although the lower and upper limits of the "fat burning" zone (67.6-87.1% maximal heart rate) were significantly lower (p < 0.05) than their counterparts in the aerobic zone (58.9-76.2%), the considerable overlap of the 2 zones would indicate that training for fat oxidation and training for aerobic fitness are not mutually exclusive and may be accomplished with the same training program. Furthermore, it was determined that this training program could simultaneously meet the requirements of the American College of Sports Medicine for both aerobic fitness and weight control. Maximal fat oxidation occurred at 54.2% maximal oxygen uptake ([latin capital V with dot above]O2max). However, the great variability in response between individuals would preclude the prediction of both the "fat burning" zone and MFO, indicating a need for measurement in the laboratory. If laboratory testing is not possible, the practitioner or subject can be reasonably confident MFO lies between 60.2% and 80.0% of the maximal heart rate.

 

[tim290280]

Probably one of the worst conclusions that could be taken from this research.

Basic summary appears to be that there isn't much difference physically between "strong" and "weak" elite powerlifters except that the biggest guys are the strongest. There is though a few indicators that short lower legs and bigger upper body girths, which along with the mesomorphy has a genetic base and could determine success.

My conclusions out of this were that PLers are built to be PLers and their get big philosophy clearly requires a frame that can support the need for more muscle.

Can Absolute and Proportional Anthropometric Characteristics Distinguish Stronger and Weaker Powerlifters?

Journal of Strength & Conditioning Research. 23(8):2256-2265, November 2009.
Keogh, Justin W L; Hume, Patria A; Pearson, Simon N; Mellow, Peter J

Abstract:
Keogh, JWL, Hume, PA, Pearson, SN, and Mellow, PJ. Can absolute and proportional anthropometric characteristics distinguish stronger and weaker powerlifters? J Strength Cond Res 23(8): 2256-2265, 2009-This study sought to compare the anthropometric profiles of 17 weaker and 17 stronger Australasian and Pacific powerlifters who had competed in a regional-, national-, or international-level powerlifting competition in New Zealand. Stronger lifters were defined as those having a Wilks score greater than 410, whereas those in the weaker group had a Wilks score less than 370. Each powerlifter was assessed for 37 anthropometric dimensions by International Society for the Advancement of Kinanthropometry (ISAK) level II and III accredited anthropometrists. Because all powerlifters were highly mesomorphic and possessed large girths and bone breadths, both in absolute terms and when expressed as Phantom-Z scores compared through the Phantom, relatively few significant anthropometric differences were observed. However, stronger lifters had significantly greater muscle mass and larger muscular girths in absolute terms as well as greater Brugsch Index (chest girth/height) and "Phantom"-normalized muscle mass, upper arm, chest, and forearm girths. In terms of the segment lengths and bone breadths, the only significant difference was that stronger lifters had a significantly shorter lower leg than weaker lifters. Because the majority of the significant differences were for muscle mass and muscular girths, it would appear likely that these differences contributed to the stronger lifters' superior performance. Powerlifters may therefore need to devote some of their training to the development of greater levels of muscular hypertrophy if they wish to continue to improve their performance. To better understand the anthropometric determinants of muscular strength, future research should recruit larger samples (particularly of elite lifters) and follow these subjects prospectively.

Not as relevant to us but there was a key point here. When testing the general fitness recommendations the 4 days of 30mins of exercise was the minimum required to illicit fat loss. The key point is that the bare minimums, and the work into it gradually mentality that we currently have promoted at us is just plain BS. If you want to have any physical achievements you literally have to be doing as much as you can. If it is easy or less than most of the time you won't achieve anything (and is why a lot of people give up no doubt).

Frequency of Exercise for Body Fat Loss: A Controlled, Cohort Study.

Journal of Strength & Conditioning Research. 23(8):2377-2380, November 2009.
Willis, F Buck 1; Smith, Forrest M 2; Willis, Adele P 3

Abstract:
Willis, FB, Smith, FM, and Willis, AP. Frequency of exercise for body fat loss: a controlled, cohort study. J Strength Cond Res 23(8): 2377-2380, 2009-The purpose of this study is to examine the changes in body fat mass of previously sedentary, deconditioned subjects who began following the U.S. Surgeon General's recommendation in frequency of exercise. Ninety subjects of both sexes were recruited; ages ranged from 22 to 74 (mean 37.5 +/- 13) years. Subjects were prescribed exercise of 4 times a week, 30 minutes of continuous exercise, for 8 weeks. Eighty subjects completed the 8-week study and were categorized based on voluntary compliance: control (no exercise); exercise less than 2 times/week; exercise 3 to 4 times/week; exercise 4 or more times/week. Body fat mass was the dependent variable in this study, as measured by air displacement plethysmography, and data analysis was accomplished with a repeated measures analysis of variance. There was a significant change in body fat mass in this study, but the only significant difference between groups was for the group that exercised 4 or more times/week, (p = 0.004). Adherence to the U.S. Surgeon General's Guidelines for frequency of exercising 4 times per week for 30 minutes was effective in reducing subjects' body fat mass in this study.

 

[philosopher]

They didn't measure enough muscles for my liking, but shows the front pull is better:

And is way better for your shoulder health.