por Fisio » Mié, 04 Sep 2013, 00:54
por Fisio » Sab, 08 Mar 2014, 00:52
The effects of 12 weeks of beta-hydroxy-beta-methylbutyrate free acid supplementation on muscle mass, strength, and power in resistance-trained individuals: a randomized, double-blind, placebo-controlled study
Studies utilizing beta-hydroxy-beta-methylbutyrate (HMB) supplementation in trained populations are limited. No long-term studies utilizing HMB free acid (HMB-FA) have been conducted. Therefore, we investigated the effects of 12 weeks of HMB-FA supplementation on skeletal muscle hypertrophy, body composition, strength, and power in trained individuals. We also determined the effects of HMB-FA on muscle damage and performance during an overreaching cycle.
A three-phase double-blind, placebo- and diet-controlled randomized intervention study was conducted. Phase 1 was an 8-week-periodized resistance-training program; Phase 2 was a 2-week overreaching cycle; and Phase 3 was a 2-week taper. Muscle mass, strength, and power were examined at weeks 0, 4, 8, and 12 to assess the chronic effects of HMB-FA; and assessment of these, as well as cortisol, testosterone, and creatine kinase (CK) was performed at weeks 9 and 10 of the overreaching cycle.
HMB-FA resulted in increased total strength (bench press, squat, and deadlift combined) over the 12-week training (77.1 ± 18.4 vs. 25.3 ± 22.0 kg, p < 0.001); a greater increase in vertical jump power (991 ± 168 vs. 630 ± 167 W, p < 0.001); and increased lean body mass gain (7.4 ± 4.2 vs. 2.1 ± 6.1 kg, p < 0.001) in HMB-FA- and placebo-supplemented groups, respectively. During the overreaching cycle, HMB-FA attenuated increases in CK (−6 ± 91 vs. 277 ± 229 IU/l, p < 0.001) and cortisol (−0.2 ± 2.9 vs. 4.5 ± 1.7 μg/dl, p < 0.003) in the HMB-FA- and placebo-supplemented groups, respectively.
These results suggest that HMB-FA enhances hypertrophy, strength, and power following chronic resistance training, and prevents decrements in performance following the overreaching.
por Sergio » Sab, 08 Mar 2014, 01:16
por Fisio » Sab, 08 Mar 2014, 03:26
por Sergio » Dom, 09 Mar 2014, 02:21
por Fisio » Dom, 09 Mar 2014, 02:47
4. William Kraemer in 2009 in the journal of Medicine and Science in sports and exercise, the highest impact journal in our field found the group on HMB gained 9 kg or 19.8 lbs of LBM over 12 weeks time without an overreaching and taper cycle.
5. In addition Paul Cribbs data found over 5 kg or 11 lbs in 10 weeks in bodybuilders with just whey protein.
por Fisio » Dom, 09 Mar 2014, 03:32
por Sergio » Lun, 10 Mar 2014, 12:28
por Fisio » Mar, 11 Mar 2014, 00:54
Journal of Applied Physiology has regretfully omitted a conflict
of interest disclosure, which was provided by the author at the time of
submission. The conflict of interest disclosure states as follows: Dr. Steven
Nissen is a professor at Iowa State University, which owns the patents related
to HMB. In addition, Dr. Nissen is the CEO of Metabolic Technologies, Inc.,
which is the licensee of the HMB patents. HMB is the subject of part of the
por Sergio » Mar, 11 Mar 2014, 01:31