Fat burning threshold

[tim290280]

This one supports the argument:

Joint Loading in the Lower Extremities during Elliptical Exercise.

APPLIED SCIENCES

Medicine & Science in Sports & Exercise. 39(9):1651-1658, September 2007.
LU, TUNG-WU 1; CHIEN, HUI-LIEN 1; CHEN, HAO-LING 2
Abstract:
Purpose: To determine the joint loading during elliptical exercise (EE) by a detailed three-dimensional dynamic analysis, and to compare the results with those during level walking.

Methods: Fifteen male adults performed level walking and EE while 3D kinematic data, right pedal reaction forces (PRF), and ground reaction forces (GRF) were measured. Pedal rate (cadence) and step length during EE without workload were set according to those measured during level walking for each subject. The motion of the body's center of mass, lower-limb-joint angles and moments were obtained.

Results: Pedal rates and step lengths were 52.20 rpm (SD = 2.34) and 50.56 cm (SD = 2.14), respectively. During early stance the vertical PRF was smaller than the GRF, and the medial and posterior shear components were greater. PRF also occurred during swing. Loading rates around heelstrike during EE were all smaller than those during walking. During EE, the peak flexion angles of the hip, knee and ankle were greater. Peak hip flexor and knee extensor moments were also greater, whereas peak ankle plantarflexor moments and all abductor moments were smaller.

Conclusions: Different lower-limb kinematics and kinetics were found between EE and level walking. Smaller vertical PRF and loading rates during EE were achieved at the expense of greater hip flexor and knee extensor moments. Use of the elliptical trainer for athletic and rehabilitative training would have to consider users' joint function and muscle strength, especially at the knee, to avoid injuries.

This one done on a different machine rejects the argument:

Medicine & Science in Sports & Exercise:Volume 39(5) SupplementMay 2007p S154-S155
Knee Joint Loads During Exercise on the Elliptical Trainer: 1205: Board #4 May 31 3:15 PM - 5:15 PM
[D-52 Thematic Poster - Equipment Mechanics and Design]
Knutzen, Kathleen M. FACSM; Lawson, Andrew; Brilla, Lorraine FACSM; Chalmers, Gordon

Western Washington Univ., Bellingham, WA.

Email: Kathy.Knutzen@wwu.edu

The elliptical trainer was developed as an exercise machine to maximize the workouts while at the same time reducing joint impact forces. There have been no studies examining the loads on the knee joint during exercise on the elliptical trainer.

PURPOSE: To evaluate the knee joint reaction forces and moments during exercise at three different incline settings on the elliptical trainer exercise machine (Precor EFX).

METHODS: Twenty-six healthy individuals with no history of lower extremity injury and with previous experience exercising on an elliptical trainer volunteered for this study (age: 22.19 ±.85 y, 169.9 ±9.8 cm, 74.0 ± 19.3kg). Motion was captured with two cameras as subjects performed exercise (120 steps/min) at three workload conditions (13, 25, and 40 degree incline). The pedals of the elliptical were fitted with three orthogonal load cells. Video (60Hz) and force data (600Hz) were synchronized and used to perform an inverse dynamics analysis.

RESULTS: Statistical analyses (repeated measures ANOVA) revealed no significant differences in the mean peak anterior shear force at 13-, 25- and 40-degrees (149 N, 156 N, and 181 N, respectively) nor in the mean peak posterior shear force acting at the knee (110 N, 113 N, and 116 N, respectively). Mean peak compressive force increased significantly (p=.003) with increased ramp inclination. Compressive force values were 796 N, 833 N, and 864 Nat 13-, 25-, and 40-degrees, respectively. Knee joint moments also significantly changed with increased ramp inclination. The mean peak extension moment increased with 8 Nm at 13-degrees, 17 Nm at 25-degrees, and 38 Nm at 40-degrees (p=.000). The mean peak flexion moment values decreased across the ramp settings with 174 Nm at 13-degrees, 94 Nm at 25-degrees, and 47 Nm at 40-degrees (p=.000).

CONCLUSIONS: Exercising on an elliptical exercise machine does not generate large forces or moments at the knee joint although compressive forces and moments increase at higher incline workloads. Knee joint loads and moments while exercising on the elliptical were comparable to those previously collected for other exercises including running, walking, stair ascent and descent, and cycling. Pedal load cells provided by Precor, Inc.

This one in a roundabout way says it isn't as good as a treadmill for patellofemoral pain:

Medicine & Science in Sports & Exercise:Volume 38(5) SupplementMay 2006p S498
Comparison of Quadriceps Femoris Activation during Elliptical and Treadmill Exercise in Athletes with Patellofemoral Pain Syndrome: 2623: Board#131 4:00 PM - 5:00 PM
Knutzen, Kathleen M. FACSM; Rodriguez, Ryan; Brilla, Lorraine FACSM; de Kubber, Lori

Western Washington Univ., Bellingham, WA.

Email: Kathy.Knutzen@wwu.edu

Patellofemoral Pain Syndrome (PFPS) is a common knee disorder and while the causative mechanisms are not clearly denned, the functional role of the Vastus Lateralis (VL) and Vastus Medialis Oblique (VMO) in controlling patellar tracking has been targeted as contributing. In treating PFPS, many physicians recommend exercise on an elliptical trainer to avoid the impact of overground or treadmill running.

PURPOSE: To compare VL and VMO muscle activation while exercising on an elliptical cross trainer (EL) and a treadmill (TM) in subjects with PFPS.

METHODS: Ten males and seven female athletes diagnosed with PFPS by the team physician volunteered as subjects (Age 21±1 6 yr; Weight 80.3±15.6 kg). Following a standardized warm-up, subjects completed two randomized exercise sessions on the El and TM ranging from 6 to 9 minutes. Electromyographic (EMG) activity of the VL and VMO was sampled (1000Hz) at baseline and at 65% of heart rate reserve obtained through a systematic workload adjustment every 3 minutes. A repeated measures ANOVA was applied to evaluate differences in the average EMG generated during the support phase for each machine.

RESULTS: As would be expected, there were significant increases (p < 0.05) in VL and VMO activation from the baseline values to 65% HRR for both the TM (VLbase=86.8±35.0 μV; VL65%=136.4+58.4 μV; VMObase=68.3+22.6 μV; VMO65%=144.1+16.0 uV) and the EL(VLbase=135.1±65.8μV;VL65%=163.3±71.7μV;VMObase=116.4±51.6μV; VMO65%=125.3±54.6 μY). Initial baselines values were significantly higher for both VL and VMO while exercising on the EL as compared to TM, however increases from baseline to 65%HRR in VL and VMO activity occurred at greater rates on the TM (VL +46%; VMO +111%) compared to El (VL +21%; VMO +8%).

CONCLUSIONS: These results suggest that there are differences in muscle activation patterns on the TM versus the EL comparing baseline to 65% HRR exercise. The higher involvement of the quadriceps muscles early in the exercise session on the elliptical compared to the lower initial involvement followed by higher rates of increase seen in the same muscles on the treadmill may influence exercise prescription for individuals with PFPS.

So like I said nothing definitive. But what you do see is that the elliptical design plays a role in how much force you get out of them and where it occurs. The studies on bike riders would probably give more indication of problems. Either way, me and my dodgy knee are steering well clear of ellipticals.

 

[Johnny Bravo]

I was reading this article on T-Nation and I thought the first part of it might be interesting for some.

http://www.t-nation.com/article/atomic_dog/cant_prove_it

 

[Zigurd]

Care to answer my question bastards ? xD

Does aerobic training burn fats and carbs, while anaerobic ONLY burn carbs ?

 

[philosopher]

Care to answer my question bastards ? xD

Does aerobic training burn fats and carbs, while anaerobic ONLY burn carbs ?

Anaerobic cardio wont burn carbs only. The amount of fat that will be burned depends on the intensity. Lots of peopel are focussing too much on how much fat they will burn during cardio. Imo interval methodes provide a better afterburn which means more cals will be burned during the day which eventually lead to more fat lose.

 

[philosopher]

A few articles from Alan aragon for those who wanna learn more about this subject

Part 1: http://alanaragon.com/myths-under-the-microscope-the-fat-burning-zone-fasted-cardio.html
Part 2: http://alanaragon.com/myths-under-the-microscope-part-2-false-hopes-for-fasted-cardio.html
Part 3: http://alanaragon.com/myths-under-the-microscope-part-3-discussion-afterthoughts.html

 

[jwill0214]

How do you guys feel about the stair stepper as a good cardio workout??

I see in a lot of bodybuilding videos that they use this for cardio a lot.

 

[tim290280]

^^ I'm a bigger fan of taking the stairs at work.

 

[Zigurd]

^^ I'm a bigger fan of taking the stairs at work.

Tim we are aware of your message, that we can perform cardio just by taking a conscious decision to take the hard way all day through any activity...

But the fact still remains that we go to the gym so that we wont have to go up the stairs. We go to the gym to concentrate all daily activity into one powerful blast of adrenalin and testosterone !

And besides, I do believe that a 30 minute cardio workout at the gym beats going up the stairs once on your way to the job.

By the way, I ALWAYS take the stairs, walk, ride a bike, run, swim, etc... instead of driving a car, going through the electrical stairs, going in a boat, etc... Bodybuilding is a lifestyle for me, being healthy overall. BUT, I still believe nothing can take away from the fact that doing cardio in the gym is good.

Even if you do cardio all day long, some more cardio in the gym will only do good !

Do you understand my point ? I feel I didn't explain properly =/
I love you Tim, don't hate meeeeeee

 

[Ironslave]

How do you guys feel about the stair stepper as a good cardio workout??

I see in a lot of bodybuilding videos that they use this for cardio a lot.

The stepmill?

Best cardio machine there is.

 

[philosopher]

The more muscles you use the better the cardio

 

[tim290280]

Tim we are aware of your message, that we can perform cardio just by taking a conscious decision to take the hard way all day through any activity...

But the fact still remains that we go to the gym so that we wont have to go up the stairs. We go to the gym to concentrate all daily activity into one powerful blast of adrenalin and testosterone !

And besides, I do believe that a 30 minute cardio workout at the gym beats going up the stairs once on your way to the job.

By the way, I ALWAYS take the stairs, walk, ride a bike, run, swim, etc... instead of driving a car, going through the electrical stairs, going in a boat, etc... Bodybuilding is a lifestyle for me, being healthy overall. BUT, I still believe nothing can take away from the fact that doing cardio in the gym is good.

Even if you do cardio all day long, some more cardio in the gym will only do good !

Do you understand my point ? I feel I didn't explain properly =/
I love you Tim, don't hate meeeeeee

I get what you are saying and I know exactly what you mean.

It is very easy to lack motivation to do any form of cardio unless you are specifically setting a task for yourself. For some it is walking the dog, for others it is getting on the treadmill at the end of a gym session. The main thing is to actually do it first, everything else is just details.

I just think that being healthy one hour (or so) a day and then being a couch potato the other 23hrs is what a lot of people end up doing. So that is why I prefer to say get outside and be active. Why go for a walk on the treadmill when you can go for a real walk outside? I know that circumstances will necessitate the latter for consistency's sake but first and foremost in our minds should be living active.

The number of people that would come to my old gym driving their cars then get on the treadmill and walk amazed me. I was then dumbfounded to find that most lived as far from the gym as they covered on the treadmill.

So yeh I get you, you get me but lets both get people thinking hard about how they live rather than just for parts of it.

 

[Ironslave]

I get what you are saying and I know exactly what you mean.

It is very easy to lack motivation to do any form of cardio unless you are specifically setting a task for yourself. For some it is walking the dog, for others it is getting on the treadmill at the end of a gym session. The main thing is to actually do it first, everything else is just details.

I just think that being healthy one hour (or so) a day and then being a couch potato the other 23hrs is what a lot of people end up doing. So that is why I prefer to say get outside and be active. Why go for a walk on the treadmill when you can go for a real walk outside? I know that circumstances will necessitate the latter for consistency's sake but first and foremost in our minds should be living active.

The number of people that would come to my old gym driving their cars then get on the treadmill and walk amazed me. I was then dumbfounded to find that most lived as far from the gym as they covered on the treadmill.

So yeh I get you, you get me but lets both get people thinking hard about how they live rather than just for parts of it.

Good post, and it's so true. What I noticed a while ago was that people driving to the gym literally always look for the closest parking spot, pretty funny.

This has the potential to get off track, especially since different people (bodybuilders) have different goals than what the general population should have, so I will leave it with this.

Be active, if you need to do cardio in the gym, cool. If you prefer to play rec basketball with your friends, also great. Just keep doing it.

 

[Zigurd]

So yeh I get you, you get me but lets both get people thinking hard about how they live rather than just for parts of it.

There is not enough room for me to post the required amount of thumbs up in this thread.