Growth hormone and muscle function responses to skeletal muscle ischemia.

[Fahsy]

http://jap.physiology.org/cgi/content/full/101/6/1588

J Appl Physiol. 2006 Dec;101(6):1588-95.

Growth hormone and muscle function responses to skeletal muscle ischemia.

Pierce JR, Clark BC, Ploutz-Snyder LL, Kanaley JA.

Department of Exercise Science, Syracuse University, Syracuse, New York, USA.

We examined the effects of ischemia (ISC) alone and with low-intensity exercise (ISC+EX) on growth hormone (GH) and muscle function responses. Nine men (22 +/- 0.7 yr) completed 3 study days: an ISC day (thigh cuff inflated five times, 5 min on, 3 min off), an ISC+EX day [knee extension at 20% maximal voluntary contraction (MVC) with ISC], and a control day. MVCs and submaximal contraction tasks (15 and 30% MVC) were performed before and following the perturbations. Surface electromyogram signals were collected from thigh muscles and analyzed for median frequency and root mean square alterations. Blood samples were collected every 10 min (190 min total) and analyzed for GH concentrations. Peak GH concentrations and GH area under the curve were highest (P < 0.01) on the ISC+EX day (7.5 microg/l and 432 microg.l(-1).min(-1), respectively) compared with the ISC (0.9 microg/l and 76.4 microg.l(-1).min(-1)), and CON (1.1 microg/l and 83.8 microg.l(-1).min(-1)) days. A greater GH pulse amplitude, mass/pulse, and production rate were also observed on the ISC+EX day (P < 0.05). Following the intervention, force production decreased on the ISC and ISC+EX days by 16.1 and 55.8%, respectively, and did not return to baseline values within 5 min of recovery. During the submaximal contractions, median frequency shifted to lower frequencies for most of the muscles examined, and root mean square electromyogram was consistently elevated for ISC+EX day. In conclusion, ISC coupled with resistance exercise acutely increases GH levels and reduces MVC, whereas ISC alone decreases force capacity, without alterations in GH levels.


Another paper pertaining to occulsion training. Obviously increasing GH would be very important for bodybuilders. It appears there is a bit of a trade off however, as the weight lifted would be reduced substantially.

[airborneninja]

I have no idea what any of this means but I'd like to!

[Fahsy]

[ QUOTE ]
I have no idea what any of this means but I'd like to!

[/ QUOTE ]

Basically if you cut off blood flow to your working muscles it appears that would cause greater hypertrophy benefits. Doing so would probably only be feasible to your arms and legs. I might try tying a belt around my quads when I do calves and see how it goes.

[Venom]

This is really good research!

What do you think the mechanism is?

My thoughts

- may be hormones like GH (this study supports that)
- Perhaps the reprefusion is playing a role on protein synthesis?
- Build up of some metabolite (perhaps lactic acid)

If you try this, let me know how it goes!

I would imagine you would want to perform more isolation movements when doing this, and that you would not want to lift super heavy, in fear of really increasing blood pressure. Particularly with upper body movements, where blood pressure tends to be greater due to lower musculature and less vascularity.

[Fahsy]

I think the mechanism has something to do with lactic acid and GH. I believe the GH response to resistance exercise is proportional to the lactic acid accumulation (but don't quote me on this).

I would probably wait to try this until it is time to deload for a week or two. I've talked to Layne (he sent me these articles originally) and he said he has tried it. He tied a belt around his legs when he was doing leg extensions (I think maybe hack squats too) and he had to lighten the weight quite a bit.

[Venom]

I'll have to give this a try.

Yes, there is around a .9 correlation with GH and lactic acid. Some good articles here.

http://www.abcbodybuilding.com/Nutri...oningpart2.php

http://www.abcbodybuilding.com/ghigfaxis.php

[Fahsy]

Awesome!