The Training Support Column MkII

[tim290280]

^^ WHAT?? BLESPHEMER!!

Actually I tend to read their methods before really taking on board anything else. There is some truely woefull "science" in exercise science. But yes it does tend to be my first port of call in my browsing, it and Am J S Med. I should look more widely but have lost the time to do so now that I have to do work research (more so than previously).

What are your preferred journals?

 

[knight_rider]

Jep, said it many time before. Tribulus is a waste of money indeed.

its good if you have a big night of rooting lined up....lol

 

[Ironslave]

^^ WHAT?? BLESPHEMER!!

Actually I tend to read their methods before really taking on board anything else. There is some truely woefull "science" in exercise science. But yes it does tend to be my first port of call in my browsing, it and Am J S Med. I should look more widely but have lost the time to do so now that I have to do work research (more so than previously).

What are your preferred journals?

You'll probably like the Journal of Exercise Physiology online, its the website ran by the American Society for Exercise Physiologists. Their articles are free, which is very cool.

http://www.asep.org/journals/JEPonline

Others

Medicine & Science Sport & Exercise
Exercise and Science Reviews
Journal of Applied Physiology
European Journal Applied Physiology
Any of the American Journal of Physiology's (theres a few)
Canadian Journal of Applied Physiology

 

[tim290280]

Attention all physios and personal trainers: It appears that it takes more than just the fancied quads to stabilise the knee. Hammys are known to contribute as well, but it also seems that the calves play a role too. Makes sense since they cross the knee joint as well.
J Knee Surg. 2003 Jul;16(3):152-8.

Soleus and gastrocnemius muscle loading decreases anterior tibial translation in anterior cruciate ligament intact and deficient knees.
Sherbondy PS, Queale WS, McFarland EG, Mizuno Y, Cosgarea AJ.
Department of Orthopedics and Rehabilitation, The Milton S. Hershey Medical Center, Hershey, Pa, USA.

This study evaluated the effect of the gastrocnemius and soleus muscles on dynamic knee stability by studying the effect of passive calf muscle loading on anterior tibial translation in normal and anterior cruciate ligament (ACL) deficient knees. Anterior tibial translation was measured bilaterally in 12 anesthetized patients with unilateral ACL-deficient knees using a KT-1000 arthrometer. An ankle-foot orthosis was used to passively dorsiflex the ankle and generate tension in the calf muscles. As the ankle flexion angle was progressively changed from 30 degrees plantar flexion to 10 degrees dorsiflexion, anterior tibial translation decreased 43% and 37% with manual maximum force in normal and ACL-deficient knees, respectively (P < .0001). These findings suggest that the calf muscles may function as dynamic knee stabilizers. Anterior tibial translation also was measured in four cadaver knees. Significant decreases were seen in anterior tibial translation with progressive ankle dorsiflexion in ACL-intact specimens and after the ACL had been cut (P < .05). This effect persisted when the gastrocnemius muscle was cut, but was lost when the soleus muscle was released. The data suggest that the soleus muscle may play a role in dynamically stabilizing the knee.

So train those calves and hammys to stop knee problems.

 

[Achilles]

Good to see your active in here again. Keep us posted tim alsway like your stuff

 

[tim290280]

Good reason to never smoke

Smoking Turns On Genes -- Permanently
Science Daily — Smoking tobacco is no longer considered sexy, but it may prove a permanent turn on for some genes. Research published in the online open access journal BMC Genomics could help explain why former smokers are still more susceptible to lung cancer than those who have never smoked.

A Canadian team led by Wan L Lam and Stephen Lam from the BC Cancer Agency, took samples from the lungs of 24 current and former smokers, as well as from non-smokers who have never smoked. They used these lung samples to create libraries using a technique called serial analysis of gene expression (SAGE), which helps to identify patterns of gene activity.

Only about a fifth of the genes in a cell are switched on at any given time, but environmental changes such as smoking lead to changes in gene activity. The researchers found changes that were irreversible, and some changes that were reversed by stopping smoking. The reversible genes were particularly involved in xenobiotic functions (managing chemicals not produced in the body), nucleotide metabolism and mucus secretion. Some DNA repair genes are irreversibly damaged by smoking, and smoking also switched off genes that help combat lung cancer development.

The researchers identified a number of genes not previously associated with smoking that are switched on in active smokers. One example is CABYR, a gene involved in helping sperm to swim and associated with brain tumours, which may have a ciliary function. The team also further investigated changes in genes involved in airway repair and regeneration, and within this group identified genes that fell into three categories following cessation of smoking: reversible (TFF3, encoding a structural component of mucus; CABYR, in it's newly discovered bronchial role), partially reversible (MUC5AC, a mucin gene) and irreversible (GSK3B, involved in COX2 regulation). These findings were tested against a second cohort of current, former and non-smokers.

"Those genes and functions which do not revert to normal levels upon smoking cessation may provide insight into why former smokers still maintain a risk of developing lung cancer," according to Raj Chari, first author of the study. The study is the largest human SAGE study reported to date, and also generated a large SAGE library for future research.

Tobacco smoking accounts for 85 percent of lung cancers, and former smokers account for half of those newly diagnosed with the disease.

Article: Raj Chari, Kim M Lonergan, Raymond T Ng, Calum MacAulay, Wan L Lam and Stephen Lam, "Effect of active smoking on the human bronchial epithelium transcriptome" BMC Genomics (in press / online August 29)

 

[tim290280]

Adipocyte Stress:
The Endoplasmic Reticulum and Metabolic Disease
Margaret F. Gregor and Gökhan S. Hotamisligil
http://www.jlr.org/cgi/reprint/R700007-JLR200v1.pdf

 

[jornT]

Brutal zero practability post.

 

[tim290280]

^^ Which one? The smoking or the fat?

Because I was just posting them because they looked interesting.

 

[Achilles]

Weres Tim at..? Didnt see him posting for a while

 

[philosopher]

Tim its about time you start updating this thread again

 

[tim290280]

Tim its about time you start updating this thread again

Or I could just go on ignoring it :methman:

Alright I'll start digging up some nerd works.

 

[tim290280]

FIBER TYPE COMPOSITION AND CAPILLARY DENSITY IN RELATION TO SUBMAXIMAL NUMBER OF REPETITIONS IN RESISTANCE EXERCISE
GERASIMOS TERZIS, KONSTANTINOS SPENGOS, PANAGIOTA MANTA, NICKOS SARRIS,
AND GIORGOS GEORGIADIS

ABSTRACT
The purpose of this study was to investigate the relationship between skeletal muscle fiber type composition and the maximum number of repetitions performed during submaximal resistance exercise. Twelve young men performed a maximum repetitions test at 85% of 1 repetition maximum (1RM) in the leg press, which was repeated after 1 week. Seven days after the second 85% 1RM test, they performed a maximum repetitions
test at 70% of 1RM in the leg press. This test, at 70% 1RM, was repeated 7 days later. One week before the initiation of the testing sessions, a biopsy sample was obtained from the vastus lateralis muscle and analyzed for fiber type distribution, fiber cross-sectional area, and capillary density (capillaries
mm22). A low and nonsignificant relationship was found between the fiber type distribution or percent fiber type area and the number of repetitions performed at either 70% or 85% 1RM. Moreover, the number of repetitions performed at 70% or 85% of 1RM was not related significantly with 1RM strength. In contrast, the
number of repetitions performed at 70% 1RM was significantly correlated with the number of capillaries per mm2 of muscle cross-sectional area (r = 0.70; p = 0.01). These results suggest
that fiber type composition is not the major biological variable regulating the number of repetitions performed in submaximal resistance exercise. Rather, it seems that submaximal strength performance depends on muscle capillary density, which is linked with the endurance capacity of the muscle tissue.

 

[philosopher]

Got something which you may find interesting as well.

J Comp Physiol . 2008 Jul 3. [Epub ahead of print]
Motor unit recruitment for dynamic tasks: current understanding and future directions.

Hodson-Tole EF, Wakeling JM.

School of Applied Physiology, Georgia Institute of Technology, Atlanta, GE, USA.

Skeletal muscle contains many muscle fibres that are functionally grouped into motor units. For any motor task there are many possible combinations of motor units that could be recruited and it has been proposed that a simple rule, the 'size principle', governs the selection of motor units recruited for different contractions. Motor units can be characterised by their different contractile, energetic and fatigue properties and it is important that the selection of motor units recruited for given movements allows units with the appropriate properties to be activated. Here we review what is currently understood about motor unit recruitment patterns, and assess how different recruitment patterns are more or less appropriate for different movement tasks. During natural movements the motor unit recruitment patterns vary (not always holding to the size principle) and it is proposed that motor unit recruitment is likely related to the mechanical function of the muscles. Many factors such as mechanics, sensory feedback, and central control influence recruitment patterns and consequently an integrative approach (rather than reductionist) is required to understand how recruitment is controlled during different movement tasks. Currently, the best way to achieve this is through in vivo studies that relate recruitment to mechanics and behaviour. Various methods for determining motor unit recruitment patterns are discussed, in particular the recent wavelet-analysis approaches that have allowed motor unit recruitment to be assessed during natural movements. Directions for future studies into motor recruitment within and between functional task groups and muscle compartments are suggested.

PMID: 18597095 [PubMed - as supplied by publisher]

Would like to see the whole text, so if someone have it please give me a PM.

 

[philosopher]

FIBER TYPE COMPOSITION AND CAPILLARY DENSITY IN RELATION TO SUBMAXIMAL NUMBER OF REPETITIONS IN RESISTANCE EXERCISE
GERASIMOS TERZIS, KONSTANTINOS SPENGOS, PANAGIOTA MANTA, NICKOS SARRIS,
AND GIORGOS GEORGIADIS

ABSTRACT
The purpose of this study was to investigate the relationship between skeletal muscle fiber type composition and the maximum number of repetitions performed during submaximal resistance exercise. Twelve young men performed a maximum repetitions test at 85% of 1 repetition maximum (1RM) in the leg press, which was repeated after 1 week. Seven days after the second 85% 1RM test, they performed a maximum repetitions
test at 70% of 1RM in the leg press. This test, at 70% 1RM, was repeated 7 days later. One week before the initiation of the testing sessions, a biopsy sample was obtained from the vastus lateralis muscle and analyzed for fiber type distribution, fiber cross-sectional area, and capillary density (capillaries
mm22). A low and nonsignificant relationship was found between the fiber type distribution or percent fiber type area and the number of repetitions performed at either 70% or 85% 1RM. Moreover, the number of repetitions performed at 70% or 85% of 1RM was not related significantly with 1RM strength. In contrast, the
number of repetitions performed at 70% 1RM was significantly correlated with the number of capillaries per mm2 of muscle cross-sectional area (r = 0.70; p = 0.01). These results suggest
that fiber type composition is not the major biological variable regulating the number of repetitions performed in submaximal resistance exercise. Rather, it seems that submaximal strength performance depends on muscle capillary density, which is linked with the endurance capacity of the muscle tissue.

Sounds logical. Capillaries improve blood perfusion through the muscles and the exhance of waste products and nutrients. An increase in capillaries is one of the reasons why endurance athletes increase their VO2 max.

 

[tim290280]

Got something which you may find interesting as well.

Would like to see the whole text, so if someone have it please give me a PM.

Yes I am interested. I tried to look it up but it doesn't seem to be at their online site. Maybe there are two with similar abbreviations.

 

[Hypocrisy86]

Hey tim My bro has a extremely high metabolism
i mean very high, 5,000+ cals a day are like a crumb to him
he still doesnt gain weight, he's 5'10 and 127lbs

 

[philosopher]

Hey tim My bro has a extremely high metabolism
i mean very high, 5,000+ cals a day are like a crumb to him
he still doesnt gain weight, he's 5'10 and 127lbs

Taper worm....

Whats his activety level atm?

 

[tim290280]

Hypo have you actually written down everything to the gram that he eats? Have you done this for an entire week/fortnight? Have you actually calculated this caloric intake or just guessed.

If you have then he sounds like he needs to go see a doctor and get some blood work or worm pills.

 

[tim290280]

Ok lets take a look at the thigh and the muscle recruitments and value of exercises. Anyone can feel free to post argument but it has to be backed up with more than "I feel this".

This questions the value of the leg extension exercise as an exercise not just from an injury standpoint.

An Electromyographical Comparison of the Squat and Knee Extension Exercises.
Journal of Strength & Conditioning Research. 8(3):178-183, August 1994.
Signorile, Joseph F. 1; Weber, Brad 2; Roll, Brad 2; Caruso, John F. 3; Lowensteyn, Ilka 3; Perry, Arlette C. 3
Abstract:
The seated knee extension is commonly used with the parallel squat to promote balance between the vastus medialis (VM) and vastus lateralis (VL). No controlled studies have examined the relative contributions of each muscle during these exercises, so this study employed EMG analysis to determine their contributions. Ten experienced lifters performed squats and knee extensions at their 10-RM. Sets were separated by 15 min rest and the order of performance was reversed between sessions, which were 1 week apart. EMG was collected on the VL and VM of the dominant leg during the first and last repetition of each exercise. Since EMG activity differed significantly between the two testing days, each was analyzed separately. No significant differences were found between the root mean square of the amplitude of the EMG for the VL and VM during either exercise. The parallel squat elicited more electrical activity than the knee extension in both muscles, and the downward shift in frequency of the EMG signal was greater for both the VM and VL during the parallel squat. The results question the value of the knee extension as a supplemental exercise in this case.

Squats are good mkay!

Knee biomechanics of the dynamic squat exercise.
Medicine & Science in Sports & Exercise. 33(1):127-141, January 2001.
ESCAMILLA, RAFAEL F.
Abstract:
ESCAMILLA, R. F. Knee biomechanics of the dynamic squat exercise. Med. Sci. Sports Exerc., Vol. 33, No. 1, 2001, pp. 127-141.

Purpose: Because a strong and stable knee is paramount to an athlete's or patient's success, an understanding of knee biomechanics while performing the squat is helpful to therapists, trainers, sports medicine physicians, researchers, coaches, and athletes who are interested in closed kinetic chain exercises, knee rehabilitation, and training for sport. The purpose of this review was to examine knee biomechanics during the dynamic squat exercise.

Methods: Tibiofemoral shear and compressive forces, patellofemoral compressive force, knee muscle activity, and knee stability were reviewed and discussed relative to athletic performance, injury potential, and rehabilitation.

Results: Low to moderate posterior shear forces, restrained primarily by the posterior cruciate ligament (PCL), were generated throughout the squat for all knee flexion angles. Low anterior shear forces, restrained primarily by the anterior cruciate ligament (ACL), were generated between 0 and 60[degrees] knee flexion. Patellofemoral compressive forces and tibiofemoral compressive and shear forces progressively increased as the knees flexed and decreased as the knees extended, reaching peak values near maximum knee flexion. Hence, training the squat in the functional range between 0 and 50[degrees] knee flexion may be appropriate for many knee rehabilitation patients, because knee forces were minimum in the functional range. Quadriceps, hamstrings, and gastrocnemius activity generally increased as knee flexion increased, which supports athletes with healthy knees performing the parallel squat (thighs parallel to ground at maximum knee flexion) between 0 and 100[degrees] knee flexion. Furthermore, it was demonstrated that the parallel squat was not injurious to the healthy knee.

Conclusions: The squat was shown to be an effective exercise to employ during cruciate ligament or patellofemoral rehabilitation. For athletes with healthy knees, performing the parallel squat is recommended over the deep squat, because injury potential to the menisci and cruciate and collateral ligaments may increase with the deep squat. The squat does not compromise knee stability, and can enhance stability if performed correctly. Finally, the squat can be effective in developing hip, knee, and ankle musculature, because moderate to high quadriceps, hamstrings, and gastrocnemius activity were produced during the squat.

Squat depth doesn't change thigh involvement

The Journal of Strength and Conditioning Research
Article: pp. 428–432 | Abstract
Volume 16, Issue 3 (August 2002)

The Effect of Back Squat Depth on the EMG Activity of 4 Superficial Hip and Thigh Muscles
ANTHONY CATERISANO1, 2, RAYMOND F. MOSS1, THOMAS K. PELLINGER1, KATHERINE WOODRUFF1, VICTOR C. LEWIS1, WALTER BOOTH1, and TARICK KHADRA1
The purpose of this study was to measure the relative contributions of 4 hip and thigh muscles while performing squats at 3 depths. Ten experienced lifters performed randomized trials of squats at partial, parallel, and full depths, using 100–125% of body weight as resistance. Electromyographic (EMG) surface electrodes were placed on the vastus medialis (VMO), the vastus lateralis, (VL), the biceps femoris (BF), and the gluteus maximus (GM). EMG data were quantified by integration and expressed as a percentage of the total electrical activity of the 4 muscles. Analysis of variance (ANOVA) and Tukey post hoc tests indicated a significant difference (p < 0.001*, p = 0.056**) in the relative contribution of the GM during the concentric phases among the partial- (16.9%*), parallel- (28.0%**), and full-depth (35.4%*) squats. There were no significant differences between the relative contributions of the BF, the VMO, and the VL at different squatting depths during this phase. The results suggest that the GM, rather than the BF, the VMO, or the VL, becomes more active in concentric contraction as squat depth increases.

Parallel (100-110 degrees) and deep squats (125-140 degrees) are better:

Joint moments of force and quadriceps muscle activity during squatting exercise
P. Wretenberg 1 , Y. Feng 1 , F. Lindberg 1 , U. p. Arboreilus 1
Scandinavian Journal of Medicine & Science in Sports
Volume 3 Issue 4, Pages 244 - 250
KEYWORDS
squatting exercise • Olympic weightlifting • hip • knee • joint load • EMG • biomechanics

ABSTRACT
The relationship between hip and knee joint load and quadriceps muscle activity during squatting exercise to different depths was studied. Eight young national class Olympic weightlifters performed squatting exercise to 4 different knee flexion angles; 45°, 90°, parallel and deep squats. They held a barbell across their shoulders with a weight of 65% of their one-repetition maximum. The loading moments of force about the hip and knee joints were calculated using a semidynamic method. Video was used for motion recording and electromyograhy for recording activity from die vastus lateralis, rectus femoris and biceps femoris muscles. The loading moment on the hip joint increased significantly from the 90° squat to the parallel, but there was no difference between the parallel and the deep. For the knee joint, there was no difference between the 45°, 90° and parallel, but for the deep squat the loading moment increased significantly. The muscular activity generally increased with increasing squatting depth, but mere were only minor insignificant differences between the parallel and the deep squats. We conclude that knee joint load can be limited by doing parallel instead of deep squats and that this will not decrease quadriceps muscle activity. To limit hip moment, the squat should not be deeper than 90°.

Deep squats aren't that bad:

J Appl Biomech. 2006 Nov;22(4):305-13.Links
Tibiofemoral joint contact force in deep knee flexion and its consideration in knee osteoarthritis and joint replacement.Nagura T, Matsumoto H, Kiriyama Y, Chaudhari A, Andriacchi TP.
Department of Orthopedic Surgery, Keio University, Shinjyuku, Tokyo, Japan.

The aim of the study was to estimate the tibiofemoral joint force in deep flexion to consider how the mechanical load affects the knee. We hypothesize that the joint force should not become sufficiently large to damage the joint under normal contact area, but should become deleterious to the joint under the limited contact area. Sixteen healthy knees were analyzed using a motion capture system, a force plate, a surface electromyography, and a knee model, and then tibiofemoral joint contact forces were calculated. Also, a contact stress simulation using the contact areas from the literature was performed. The peak joint contact forces (M +/- SD) were 4566 +/- 1932 N at 140 degrees in rising from full squat and 4479 +/- 1478 N at 90 degrees in rising from kneeling. Under normal contact area, the tibiofemoral contact stresses in deep flexion were less than 5 MPa and did not exceed the stress to damage the cartilage. The contact stress simulation suggests that knee prosthesis having the contact area smaller than 200 mm2 may be problematic since the contact stress in deep flexion would become larger than 21 MPa, and it would lead damage or wear of the polyethylene.

Weightlifting style squatting rocks:

High- and low-bar squatting techniques during weight-training.

Applied Sciences

Medicine & Science in Sports & Exercise. 28(2):218-224, February 1996.
WRETENBERG, PER; FENG, YI; ARBORELIUS, ULF P.
Abstract:
Eight Swedish national class weightlifters performed "high-bar" squats and six national class powerlifters performed "low-bar" squats, with a barbell weight of 65% of their 1 RM, and to parallel- and a deep-squatting depth. Ground reaction forces were measured with a Kistler piezo-electric force platform and motion was analyzed from a video record of the squats. A computer program based on free-body mechanics was designed to calculate moments of force about the hip and knee joints. EMG from vastus lateralis, rectus femoris, and biceps femoris was recorded and normalized. The peak moments of force were flexing both for the hip and the knee. The mean peak moments of force at the hip were for the weightlifters 230 Nm (deep) and 216 Nm (parallel), and for the powerlifters 324 Nm (deep), and 309 Nm(parallel). At the knee the mean peak moments for the weightlifters were 191 Nm (deep) and 131 Nm (parallel), and for the powerlifters 139 Nm (deep) and 92 Nm (parallel). The weightlifters had the load more equally distributed between hip and knee, whereas the powerlifters put relatively more load on the hip joint. The thigh muscular activity was slightly higher for the powerlifters.

I can't quickly find the article on the recommended deep squatting to 120-140 degrees. If anyone else does please post it here as the article also acts as a review on squatting for strength and sports.