Quote:
Originally Posted by Gill
Macro, the PRJ you posted has recently been all but disproven by a group at the University of Connecticut Kinseiology Research Lab.
A sample of 55 males and 45 females trained their non-dominant arm via curls for a set amount of time (8 weeks I think). At the end, their arms were measured using calipers (basic BF measurement tool). At first, it seemed they had lost fat in that area while maintaining it in their opposite arm; however, after doing MRIs on the subject's arms, it was revealed that the fat was simply displaced by growing muscle. The fat was still there, just slightly pushed aside.
Obviously its just one study, but UCs physiologists are renowned for their research teams in most PRJ circles.
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MRI is not a good measure of adipose tissue, the fact that they did not use DEXA certainly does not reflect well on the study. that being said local lipolytic effects seem to vary between muscle groups. And unless there is caloric deficit would say that much longer period of time would be necessary to see significant lateral lipolytic effect. Often find that study parameters are not well designed. Though will look at the full study. those are just thoughts based on what you posted.
1: Am J Physiol Endocrinol Metab. 2007 Feb;292(2):E394-9. Epub 2006 Sep 19. Links
Are blood flow and lipolysis in subcutaneous adipose tissue influenced by contractions in adjacent muscles in humans?Stallknecht B, Dela F, Helge JW.
Department of Medical Physiology, The Panum Institute, Blegdamsvej 3, DK-2200 Copenhagen N, Denmark.
B.Stallknecht@mfi.ku.dk
Aerobic exercise increases whole body adipose tissue lipolysis, but is lipolysis higher in subcutaneous adipose tissue (SCAT) adjacent to contracting muscles than in SCAT adjacent to resting muscles? Ten healthy, overnight-fasted males performed one-legged knee extension exercise at 25% of maximal workload (W(max)) for 30 min followed by exercise at 55% W(max) for 120 min with the other leg and finally exercised at 85% W(max) for 30 min with the first leg. Subjects rested for 30 min between exercise periods. Femoral SCAT blood flow was estimated from washout of (133)Xe, and lipolysis was calculated from femoral SCAT interstitial and arterial glycerol concentrations and blood flow. In general, blood flow and lipolysis were higher in femoral SCAT adjacent to contracting than adjacent to resting muscle (time 15-30 min; blood flow: 25% W(max) 6.6 +/- 1.0 vs. 3.9 +/- 0.8 ml x 100 g(-1) x min(-1), P < 0.05; 55% W(max) 7.3 +/- 0.6 vs. 5.0 +/- 0.6 ml x 100 g(-1) x min(-1), P < 0.05; 85% W(max) 6.6 +/- 1.3 vs. 5.9 +/- 0.7 ml x 100 g(-1) x min(-1), P > 0.05; lipolysis: 25% W(max) 102 +/- 19 vs. 55 +/- 14 nmol x 100 g(-1) x min(-1), P = 0.06; 55% W(max) 86 +/- 11 vs. 50 +/- 20 nmol x 100 g(-1) x min(-1), P > 0.05; 85% W(max) 88 +/- 31 vs. -9 +/- 25 nmol x 100 g(-1) x min(-1), P < 0.05). In conclusion, blood flow and lipolysis are generally higher in SCAT adjacent to contracting than adjacent to resting muscle irrespective of exercise intensity. Thus specific exercises can induce "spot lipolysis" in adipose tissue.