Bigmurph6
Banned
syn.ß-Hydroxyisovaleric acid
PERFORMANCE VALIDATION SCORES
Combined 8
Clinical Support Rating 5
Empirical Evidence Rating 3
Description
HMB (beta-hydroxy-beta-methylbutyrate) is a naturally occurring metabolite of the essential branched chain amino acid leucine. This nutrient is obtained in small amounts from a variety of food sources, including catfish, breast milk, and citrus fruits. The human body also produces HMB from leucine, which accounts for approximately 5% of its total metabolism.
The approximate daily production of HMB in humans is estimated to range from 1/4 to 1 gram, depending on the concentration of protein (specifically leucine)
in the diet.:- As a byproduct of the metabolism of an essential nutrient, HMB is not considered an essential dietary nutrient itself. In supplemental form, HMB is most often supplied as a calcium salt.
The exact role of HMB in exercise physiology is not fully understood. It appears to influeno
biological nonThe exact role of HMB in exercise physiology is not fully understood. It appears to influence a number of biological processes, particularly those involved in muscle repair and resistance to damage. However, its exact mechanism of action in these processes is unknown. HMB appears to exert some of its activity via stimulation of the MAPK and PI3K pathways, and increasing the expression of IGF-1 mRNA levels.
This leads to reduced muscle cell damage and increased myoblast (a precursor cell used for
repair/growth) production. It has been shown to support a positive protein balance, specifically by reducing the protein catabolism phase of protein turnover, HMB has also been demonstrated to reduce creatine phosphokinase (a marker of muscle damage) and inhibit lactate dehydrogenase (an enzyme responsible
for forming lactate in the muscles) after intense endurance exercise.
HMB has long been the subject of controversy,
mainly concerning the manner in which it was marketed early on. Much of this has been attributed to former EAS owner Bill Phillips, who compared HMB to Deca-Durabolin, a popular anabolic steroid, when first introducing the readers of his magazine (Muscle-Media 2000) to the new supplement. The supplement,
of course, failed to perform in any manner that resembled this drug, which resulted in a great deal of nesative backlash towards Phillips and HMB. For years. this public relations disaster overshadowed much of the active research on this substance, some of it very positive. Today, the phrase “feels like Deca” has become synonymous with the exaggeration of a supple-
ment’s efficacy.
miss.
Promoted Benefits
HMB is promoted to help increase muscle mass,
strength, endurance, and aerobic performance.
Clinical Studies
HMB has been the subject of extensive clinical study.
A number of placebo-controlled investigations support the use of this supplement to enhance
exercise/athletic performance. This ingredient has been shown to improve performance in placebo-controlled studies with experienced resistance-trained adults. Its Clinical Support Rating is 5 (5/5).
One placebo-controlled investigation published in
May 2009 examined the effect of nine weeks of HME supplementation in resistance-trained men. The consumption of 3 grams of HMB per day tended to produce a small increase in average strength (1.6%) compared to placebo. The increase was mainly attributed to improvements in lower body strength, which improved on an average of 9.1%. Measures of upper body strength (bench press, bicep curl) were inconclusive. Fat free mass increased only slightly (.2%) over placebo.
The Journal of Strength Conditioning Research conducted a comprehensive analysis of all HMB studies involving resistance training published prior to May 2009.Nine qualifying placebo-controlled studies were reviewed, involving a total of 394 participants. A combined evaluation of all studies showed a slight average increase in strength (3.7%) with HMB supplementation. The most consistent improvements.were noticed in the lower body strength measures of untrained subjects. When applied to individuals with training experience, positive outcomes in strength measures were less consistent, and usually minor. Researchers could not detect any significant effect of HMB on muscle mass or body composition. With regard to its effects on aerobic metabolism, a placebo-controlled study examined the effects of five weeks of HMB supplementation (3g/day) on running performance in a group of active college students. Each subject completed interval training on a tread-mill, and oxygen consumption was measured with the
use of a respiratory-gas analyzer. Supplementation
with HMB resulted in an 8.4% increase in maximal
oxygen consumption (Vo2max).
Empirical Evidence
HMB has been widely used as a stand-alone product. The empirical evidence on this supplement has been mixed. Many users do report positive results, particularly with muscle endurance and overall athletic/exercise performance. The improvements are typically modest and difficult to accurately quantify, but tangible to these users nonetheless. Many become loyal repeat users of HMB. A seemingly equal percentage of users, however, do not seem to notice strong positive results with this supplement. Given that only modest improvements appeared during clinical studies with trained subjects, it is possible that benefits are imparted to a greater percentage of users, but they are overlooked. HMB has an Empirical Evidence Rating
of 3 (3/5).
Effective Dosage
Based on clinical studies, a dosage of 3 grams per day is recommended.
Side Effects / Safety
HMB was well tolerated in all clinical studies, with no significant adverse effects.
PERFORMANCE VALIDATION SCORES
Combined 8
Clinical Support Rating 5
Empirical Evidence Rating 3
Description
HMB (beta-hydroxy-beta-methylbutyrate) is a naturally occurring metabolite of the essential branched chain amino acid leucine. This nutrient is obtained in small amounts from a variety of food sources, including catfish, breast milk, and citrus fruits. The human body also produces HMB from leucine, which accounts for approximately 5% of its total metabolism.
The approximate daily production of HMB in humans is estimated to range from 1/4 to 1 gram, depending on the concentration of protein (specifically leucine)
in the diet.:- As a byproduct of the metabolism of an essential nutrient, HMB is not considered an essential dietary nutrient itself. In supplemental form, HMB is most often supplied as a calcium salt.
The exact role of HMB in exercise physiology is not fully understood. It appears to influeno
biological nonThe exact role of HMB in exercise physiology is not fully understood. It appears to influence a number of biological processes, particularly those involved in muscle repair and resistance to damage. However, its exact mechanism of action in these processes is unknown. HMB appears to exert some of its activity via stimulation of the MAPK and PI3K pathways, and increasing the expression of IGF-1 mRNA levels.
This leads to reduced muscle cell damage and increased myoblast (a precursor cell used for
repair/growth) production. It has been shown to support a positive protein balance, specifically by reducing the protein catabolism phase of protein turnover, HMB has also been demonstrated to reduce creatine phosphokinase (a marker of muscle damage) and inhibit lactate dehydrogenase (an enzyme responsible
for forming lactate in the muscles) after intense endurance exercise.
HMB has long been the subject of controversy,
mainly concerning the manner in which it was marketed early on. Much of this has been attributed to former EAS owner Bill Phillips, who compared HMB to Deca-Durabolin, a popular anabolic steroid, when first introducing the readers of his magazine (Muscle-Media 2000) to the new supplement. The supplement,
of course, failed to perform in any manner that resembled this drug, which resulted in a great deal of nesative backlash towards Phillips and HMB. For years. this public relations disaster overshadowed much of the active research on this substance, some of it very positive. Today, the phrase “feels like Deca” has become synonymous with the exaggeration of a supple-
ment’s efficacy.
miss.
Promoted Benefits
HMB is promoted to help increase muscle mass,
strength, endurance, and aerobic performance.
Clinical Studies
HMB has been the subject of extensive clinical study.
A number of placebo-controlled investigations support the use of this supplement to enhance
exercise/athletic performance. This ingredient has been shown to improve performance in placebo-controlled studies with experienced resistance-trained adults. Its Clinical Support Rating is 5 (5/5).
One placebo-controlled investigation published in
May 2009 examined the effect of nine weeks of HME supplementation in resistance-trained men. The consumption of 3 grams of HMB per day tended to produce a small increase in average strength (1.6%) compared to placebo. The increase was mainly attributed to improvements in lower body strength, which improved on an average of 9.1%. Measures of upper body strength (bench press, bicep curl) were inconclusive. Fat free mass increased only slightly (.2%) over placebo.
The Journal of Strength Conditioning Research conducted a comprehensive analysis of all HMB studies involving resistance training published prior to May 2009.Nine qualifying placebo-controlled studies were reviewed, involving a total of 394 participants. A combined evaluation of all studies showed a slight average increase in strength (3.7%) with HMB supplementation. The most consistent improvements.were noticed in the lower body strength measures of untrained subjects. When applied to individuals with training experience, positive outcomes in strength measures were less consistent, and usually minor. Researchers could not detect any significant effect of HMB on muscle mass or body composition. With regard to its effects on aerobic metabolism, a placebo-controlled study examined the effects of five weeks of HMB supplementation (3g/day) on running performance in a group of active college students. Each subject completed interval training on a tread-mill, and oxygen consumption was measured with the
use of a respiratory-gas analyzer. Supplementation
with HMB resulted in an 8.4% increase in maximal
oxygen consumption (Vo2max).
Empirical Evidence
HMB has been widely used as a stand-alone product. The empirical evidence on this supplement has been mixed. Many users do report positive results, particularly with muscle endurance and overall athletic/exercise performance. The improvements are typically modest and difficult to accurately quantify, but tangible to these users nonetheless. Many become loyal repeat users of HMB. A seemingly equal percentage of users, however, do not seem to notice strong positive results with this supplement. Given that only modest improvements appeared during clinical studies with trained subjects, it is possible that benefits are imparted to a greater percentage of users, but they are overlooked. HMB has an Empirical Evidence Rating
of 3 (3/5).
Effective Dosage
Based on clinical studies, a dosage of 3 grams per day is recommended.
Side Effects / Safety
HMB was well tolerated in all clinical studies, with no significant adverse effects.
Last edited:
