Wednesday, May 7, 2008

Research Update for May Hormones, Muscle Growth and Inflammation

Hypertrophy with unilateral resistance exercise occurs without increases in endogenous anabolic hormone concentration.

Conclusion: “Unilateral training induced local muscle hypertrophy only in the exercised limb, which occurred in the absence of changes in systemic hormones that ostensibly play a role in muscle hypertrophy.”

My comments
Muscle hypertrophy (increasing muscle mass to get hyoooooooge) is a complicated process and although anabolic hormones do help, they are NOT required for muscle growth!

Cross-transfer effects of resistance training with blood flow restriction.

CONCLUSION: “The results indicate that low-intensity resistance training increases muscular size and strength when combined with resistance exercise with blood flow restriction for other muscle groups. It was suggested that any circulating factor(s) was involved in this remote effect of exercise on muscular size.”

My comments
Nothing like science to show different results from different studies! This one showing a systemic effect due to exercise (probably anabolic hormones but could be related to the nervous system). Previous studies have shown that there is a cross transfer from one limb to the next, so if I only do RIGHT bicep curls, my LEFT bicep will actually increase in strength to some degree

Growth hormone isoform responses to GABA ingestion at rest and after exercise.

CONCLUSIONS: “Our data indicate that ingested GABA elevates resting and postexercise irGH and ifGH concentrations. The extent to which irGH/ifGH secretion contributes to skeletal muscle hypertrophy is unknown, although augmenting the postexercise irGH/ifGH response may improve resistance training-induced muscular adaptations.”

My comments
I can see the supplement add now "GABBA increases GH!!!" While that may be true, this does NOT gaurantee any performance (increased muscle, decreased fat) changes. Yes the amount of GH (dose) does matter, but newer research is showing that how and when (pattern) of release is also very important.

Myocardial gene expression in heart failure patients treated with cardiac resynchronization therapy responders versus nonresponders.

CONCLUSIONS: “In HF patients with electromechanical cardiac dyssynchrony, functional improvement related to CRT is associated with favorable changes in established molecular markers of HF, including genes that regulate contractile function and pathologic hypertrophy.”

My comments
This study shows the amazing ability of the body to ADAPT! Despite what we throw at it, the body will almost ALWAYS ADAPT! This adaptation could be good or bad however. In this case with a better stimulus (CRT--cardiac resynchronization therapy--think of a fancy pacemaker for BOTH sides of the heart) the heart adapted in a POSITIVE fashion, all the way down to molecular markers. Amazing.

The salivary testosterone and cortisol response to three loading schemes.

Conclusion:” The similar T and C responses to the power and maximal strength schemes (of equal volume) support such a view and suggest that differences in load intensity, rest periods, and technique are secondary to volume. Because the acute hormonal responses to resistance exercise contribute to protein metabolism, then load volume may be the most important workout variable activating the endocrine system and stimulating muscle growth.”

My comments
See my above comments--ha! I wish more studies would measure hormonal changes AND performance changes. Most athletes only care about performance changes and you will not have the ability (most of us) to measure hormones anyway. Remember, hormones are only MESSENGERS!!!! Create the best stimulus first and then recover.

Effects of short-term hypocaloric diet on sympatho-vagal interaction assessed by spectral analysis of heart rate and blood pressure variability during stress tests in obese hypertensive patients.

Conclusion:” The LF/high frequency component (HF) ratio of the RR interval at rest on the regular-calorie diet was negatively correlated with the decrease in blood leptin concentration. These results suggest that the autonomic nervous function assessed by analysis of heart rate and blood pressure variability during stress tests may be improved by weight loss due to a short-term low-calorie diet in obese patients with hypertension.”

My comments
Show us again that the nervous system is running the show!

Effects of exercise on adipokines and the metabolic syndrome.

Conclusion: “Future studies are needed to investigate the cellular mechanisms by which exercise training affects inflammation and whether alterations in inflammation are one mechanism by which exercise improves components of the metabolic syndrome in at-risk individuals.”

My comments
Watch for inflammation to continue to play a huge role in exercise physiology and many other fields. Check out the guest blog by Dr. Lonnie Lowery HERE

Interleukin-6 markedly decreases skeletal muscle protein turnover and increases non-muscle amino acid utilization in healthy individuals.

Conclusion: “We demonstrated that IL-6 profoundly alters amino acid turnover. A substantial fall in plasma amino acids was observed with a concomitant 50% decrease in muscle protein turnover, however modest increase in net muscle degradation. We hypothesize that the profound reduction in muscle protein turnover and modest increase in net degradation is primarily caused by the reduced plasma amino acid availability and not directly mediated by IL-6.”

My comments

Most inflammatory compounds are probably not just "good" or "bad". Some is probably needed for a response, but too much will be an issue. Some inflammation is probably needed for optimal muscle growth (hypertrophy) but too much will dampen the optimal response. So how much? Good question and I really have no idea yet!

Any comments, let me know. Hope you enjoyed this highly geeeked out look at some brand new research!