B-hydroxy+B-methylbutyrate+(HMB)

//**WARNING:**//
//**"This statement has no been evaluated by the FDA. This product is not intended to diagnose, treat, cure, or prevent any disease."**//

**DEFINITION:**
During exercise, muscles are damaged, causing muscle protein to break down. HMB, a metabolite of leucine (a branched-chain amino acid), helps prevent protein breakdown.

**SOURCES:**
Approximately 5% of dietary leucine is oxidized into HMB, and HMB appears to be the main metabolite of leucine that more effectively prevents the breakdown of muscle protein. When compared to leucine, HMB appears to be significantly more potent on a gram per gram basis at attenuating the rate of muscle protein breakdown but is less effective than leucine at inducing muscle protein synthesis. Due to this, HMB is marketed as an anti-catabolic agent (purposed to reduce the rate of muscle breakdown) rather than an anabolic agent (purposed to increase muscle mass). (//http://examine.com/supplements/hmb//)

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HMB appears to be significantly more potent as an anti-catabolic agent rather than as an anabolic agent. HMB, currently, appears to be a beneficial supplement for the purpose of reducing muscle wasting during periods of catabolism (cancer, AIDS, caloric restriction).=====
 * =====HMB has been reported to improve training adaptations in untrained individuals who are initiating training as well as help reduce muscle breakdown in runners.=====
 * HMB has also been shown to decrease fat while also increasing lean muscle mass
 * It can also provide other health benefits such as lowering LDL levels and it has shown to promote wound healing.
 * With 2g of HMB (combined with [|5g L-Arginine] and 1.5g L-Lysine) were able to improve muscular control and power output over 12 weeks in women (with an average age of 76) without affecting lean mass.
 * The study noted a trend in increased lean mass with a subsequent study confirming an increase in lean mass, but without improvements in muscle function.One study adding[| Vitamin D] found benefit to both strength and lean mass over the course of a year.
 * For older adults participating in weight training, supplemental HMB was associated with an increase in lean mass (0.8kg/1.75lb over 8 weeks) without affecting fat mass.
 * HMB supplementation has been confirmed to be anticatabolic in periods of high risk muscular wasting (cancer cachexia, AIDS, bedrest) at a feasible supplemental dosage, but there is insufficient evidence to properly assess their role in athletes. It appears to be better than leucine at this job, but requires more robust evidence to confirm. (//Examine.com//)

**USAGE:**
Taking protein and amino acids after a workout can help replace lost protein, and build more. The presence of HMB signals muscle cells to preserve the existing muscle, thereby promoting additional muscle growth and faster muscle development and recovery. This helps you build muscle mass, muscle strength, and muscle endurance.
 * HMB supplementation at up to 3g daily has been demonstrated to be very well tolerated, and it is suspected that higher doses are equally safe
 * Human toxicological studies have noted that approximately 6g of HMB daily (78mg/kg) for one month in untrained young males did not show any toxic effects
 * 3g of HMB daily for up to 8 weeks in both youth and older persons did not alter toxicity in blood serum
 * Unless you have been advised by a medical doctor not to take HMB, anyone can use it.
 * Overall, standard doses of HMB appear to be well tolerated over long periods of time.

**WARNINGS:**
HMB is not a banned substance or a prohibited supplement (IOC,WADA,USADA). However, some organizations may be against their athletes from taking it such as the NCAA. Did not find any reports on any known side effects.

EFFECTIVENESS: 2/5
The dietary supplement beta-hydroxy-beta-methylbutyrate (HMB) is claimed to increase strength, lean body mass, and decrease fat mass when used in conjunction with resistance training. Although there is some support for these claims, the evidence is not conclusive.Therefore, we aimed to further elucidate the effects of HMB supplementation in trained men. A randomized, double-blind, controlled study design was used to investigate the effects of supplementing 22 resistance trained men with 3 g.d of HMB or corn starch placebo for 9 weeks with resistance training. The effect of HMB on strength was determined using the 1-repetition maximum (1RM) method for the lower body (leg extension) and upper body (bench press, bicep preacher curl) at baseline and after the supplementation period. Body composition was assessed by skinfolds and bioelectrical impedance analysis (BIA). Overall, 9 weeks' HMB supplementation resulted in a clear-cut, trivial increase in combined averaged strength measures of 1.6% (90% confidence limits: +/-4.3%). When considered in isolation, however, leg extension 1RM increased by a substantial 9.1% (90% confidence limits: +/-7.5%), but the effect on upper-body strength was inconclusive (bench press: -1.9 +/- 9.3%; bicep curl: -1.7 +/- 4.7%). Based on BIA estimates, HMB had a decreasing (although inconclusive) influence on fat mass of -9 +/- 14%, but it had a clear, trivial effect on fat-free mass of 0.2 +/- 2.2%. The magnitude of change in body mass was trivial, but the probability of substantial reductions in skinfold thicknesses ranged from negligible to likely. In previously trained men, supplementation of HMB in conjunction with resistance training provides a substantial benefit to lower-body strength, but it has negligible effects on body composition. ( //Journal of Strength and Conditioning Research//)
 * The free acid form appears to be better absorbed and reaches a serum peak level quicker than the calcium salt form of HMB. (//Examine.com//)
 * In regards to animal studies, 460mg/kg HMB daily to middle aged rats appears to be effective in reducing the rate of motor decline and muscular cross-sectional area during the subsequent aging process, but failed to affect lean mass. When this dose is given to female aged rats, the increase in muscle mass and power output seen with exercise is not augmented. (//Examine.com//)
 * There is limited evidence to support the idea that HMB improves power output. HMB taken before workouts has failed to reduce soreness enough to promote power output in the 72 hours measured afterwards and taking HMB during your training regimen does not appear to be better than placebo. (//Examine.com)//

SAFETY: 4/5
Insulin has been noted to be acutely induced by HMB supplementation, although it appears to be disconnect from a large reduction in blood glucose (this study noting that 320mg/kg cause a 245% increased in insulin with a 6% reduction of glucose) and its receptor's expression increased but only in liver tissue (not in skeletal muscle). Similar to leucine, HMB supplementation may cause acute increases in insulin release from the pancreas.

Toxicology testing has noted that the No Observed Adverse Effect Level (NOAEL; the highest dose not associated with any toxic signs) for HMB oral ingestion in rats is 3490mg/kg for male rats and 4160mg/kg for female rats; this is an estimated human equivalent of 558mg/kg and 665mg/kg, and assuming a body weight of 150lbs equates to 38g (males) and 45g (females).

Human toxicological studies have noted that approximately 6g HMB daily (78mg/kg) for one month in untrained young males subject to exercise did not show any toxic effects on serum parameters (half the dose had a spontaneous increase in basophils, considered to be insignificant) and 3g of HMB daily for up to 8 weeks in both youth and older persons has similarly failed to alter toxicological parameters in serum and this dose has been safe for one year of administration (study confounded with L-lysine and [|L-Arginine] ingestion). Overall, standard doses of HMB appear to be well tolerated over long periods of time.

**HMB-Fa**

 * $49.99 per container @ 3 servings per day amounts to $1.79 per serving (1 Month supply)
 * Gel Capsule
 * Less Popular (Less researched)
 * Greater Bioavailability



**Ca-HMB**

 * $28.87 @ 3 servings per day amounts to $0.96 (1 Month supply)
 * Capsule
 * More Popular, more researched



EASE OF USE: 5/5
Supplementation of HMB tends to be in the dosage range of 1-3g daily for the purpose of reducing muscle mass losses over time (anti-catabolic). As HMB is said to be 20-fold more potent than leucine for this purpose, it is seen as equivalent to 20-60g of leucine supplementation. HMB is to be taken 30-45 minutes before a workout.

**REFERENCES:**

 * 1) Thomson, J., Watson, P., & Rowlands, D. (n.d.). Effects of Nine Weeks of β-Hydroxy-β- Methylbutyrate Supplementation on Strength and Body Composition in Resistance Trained Men. Journal of Strength and Conditioning Research, 827-835
 * 2) Examine.com. HMB - Scientific Review on Usage, Dosage, Side Effects | Examine.com. 2015. Available at: http://examine.com/supplements/hmb/. Accessed November 19, 2015.
 * 3) Kreider, Ferreira, Wilson, Almada. Effects of Calcium â-Hydroxy-â-methylbutyrate (HMB) Supplementation During Resistance-Training on Markers of Catabolism, Body Composition and Strength. International Journal of Sports Medicine. 1999;20(8):503-509. doi:10.1055/s-1999-8835.