HMB

What is HMB?

HMB (hydroxy beta methylbutyrate) is a derivative of the branched-chain amino acid leucine that is formed in the body during the metabolism of leucine. HMB plays an important role in protein metabolism in the human body and is also thought to play a significant role in the well-documented anabolic and anticatabolic effects of leucine. Unfortunately, only about 5% of dietary L-leucine is converted to HMB in the human body, which equates to just 1.5 grams of HMB produced daily on an average high-protein sports diet. Against this background, it is not surprising that numerous scientific studies have shown that supplementation with HMB has pronounced anabolic and anti-catabolic effects and can promote muscle building and fat loss.

HMB increases the ability of the organism under high stress, such as intense training to minimize protein breakdown of the muscle cell. Minimizing protein breakdown leads to a better and faster increase in muscle mass and strength. 3 g per day has been shown to be beneficial according to recent studies. HMB is found in foods such as alfalfa, grapefruits and catfish. It is formed in the human body as a derivative of the amino acid leucine. HMB has been the subject of extensive medical research in recent years.

The saga of this incredible substance began in 1988 when a certain Dr. Nissen, a veterinarian and researcher at Iowa State University, instructed a group of students to feed a substance called -hydroxy -methylbutyrate to a few sheep to see if it could increase meat production. A small amount of -hydroxy -methylbutyrate (HMB) was synthesized and they went to work. To everyone's amazement, the initial results were so promising that further trials were soon started. After a few years, it was clear that HMB would be a new superstar in the sports world.

The tests on animals went so well that the application on humans was started. Here, the results were also stunning. Students who received HMB and exercised at the same time gained muscle mass and lost fat - the ideal combination. Further research followed and soon it was clear that HMB was not just a "fashion gimmick" but a highly effective, natural means of enhancing performance. At the 1996 Olympic Games in Atlanta, insiders report that the majority of medal winners took HMB.

HMB is a breakdown product of the amino acid leucine, which occurs naturally in the body. Various foods also contain HMB, but only in minimal amounts. Therefore, HMB is practically free of side effects. Recent research reports even suggest that HMB may also improve endurance performance. Older individuals (one study used 65-80 year old subjects) also respond excellently to HMB! HMB is introduced into the muscle metabolism and influences the protein synthesis there.

How does HMB work?

The well known anabolic effects of HMB are attributed, among other things, to a stimulation of protein synthesis via an enhancement of the effects of the mTOR signaling pathways and an upregulation of IGF-1 gene expression in skeletal muscle. Scientific studies have shown that the muscle-building effect of HMB is stronger than that of the prohormones DHEA and androstenedione.

At the same time, HMB inhibits a group of catabolic enzymes that promote muscle mass breakdown, giving it a powerful anti-catabolic effect that protects against muscle breakdown. In addition, HMB reduces the amount of muscle damage that inevitably occurs during training, which means that recovery after training is faster and you are ready for the next intense training session.

In one scientific study, bodybuilders had built three times as much muscle and strength after taking HMB for three weeks as athletes in a comparison group who followed the same sports and nutrition program but did not take HMB. In another study, bodybuilders taking 3g of HMB per day also showed significantly more strength and muscle gain compared to a control group. In addition, the HMB users had significantly reduced the body fat percentage.

These two studies confirm the findings of earlier research on animals, in which muscle gains averaging 20 to 30 percent were measured through the administration of HMB. The effect of HMB is probably based on the prevention of exercise-induced muscle damage (in the form of minute muscle fiber tears) and on minimizing proteolysis, i.e. muscle protein breakdown after heavy physical exertion (anti-catabolic effect).

Furthermore, HMB increases protein efficiency, i.e. a protein fattening with approx. 4gr. Protein per kg body weight has the same muscle building effect as with 2gr. protein per kg body weight and additional intake of HMB. At the same time it also seems to accelerate the burning of fatty acids - an interesting double effect for anyone who wants to reduce body fat.

Who can benefit from HMB supplementation?

In principle, anyone who wants to build muscle and strength can benefit from the anabolic effects of HMB. Interestingly, HMB seems to have a particularly strong muscle-building effect in novice athletes and during the first years of training. Dieting athletes can also benefit from HMB supplementation, as HMB effectively counteracts diet-induced muscle loss during strict dieting while promoting fat loss. In addition to athletes and dieters, health-conscious individuals can also benefit from HMB supplementation, as HMB can lower blood pressure and levels of harmful LDL cholesterol, as well as stimulate immune system function.

HMB and creatine - a highly effective combination!

Scientific studies have shown that HMB is about as effective as creatine in promoting muscle growth. Since creatine and HMB exert their effects through completely independent pathways, their individual effects add up when used in combination. In fact, studies have shown that subjects who combined creatine with HMB built 30% more muscle mass than subjects who used creatine alone.

What are the main benefits of HMB?

• Possesses anabolic effects that promote muscle growth
• Stimulates protein synthesis
• May counteract diet-induced muscle loss through an anticatabolic effect
• Protection of muscle cells from exercise-induced damage and acceleration of recovery after exercise
• Supports the reduction of body fat
• Delaying exhaustion during exercise and increasing aerobic and anaerobic endurance
• Lowering blood pressure and cholesterol levels
• Improving the function of the immune system

Consumption recommendation

Initially, a loading phase of one week is recommended, during which one should consume five to six grams of HMB. After that, three grams per day is sufficient. Since HMB has a half-life of only about 2 hours, it must be taken several times a day. HMB can be combined well with creatine-containing supplements, as it reduces the breakdown of creatine phosphates and thus indirectly helps in strength and muscle building. HMB should be taken with carbohydrates (e.g. carbohydrate drink). Since HMB acts directly in muscle cells, increased insulin secretion (carbohydrates cause insulin secretion) may result in more HMB being absorbed into cells and lead to better results. Half of the daily dosage should be taken immediately after training.

Side effects

Apart from acne, no side effects or intolerances are known to date, nor are acute risks of overdose. There are no studies yet on risks associated with prolonged use. Therefore, be careful, contact your doctor if you observe side effects that you associate with HMB intake. After all, HMB supplements have only been around since 1995, so observations of effects and side effects to date are not conclusive. If you want to reduce protein breakdown in the body, it is essential that you meet at least the minimum daily requirement of essential nutrients (carbohydrates, fat, protein, vitamins, minerals, etc.).

One more thing, I have read in many reports of athletes who had no performance-enhancing effect from HMB intake. This indicates that they have not dosed optimally. With hardly any other supplement is the intake method so crucial for the effect. Incorrectly consumed it does not bring anything and ideally dosed it is one of the most effective supplements at all.

References

1. Nissen S, Panton L, WilhelmR, Fuller JC (1996) Effect of HMß supplementation on strength and body composition of trained and untrained males undergoing intense resistance training FASEB J. 10: A287.
2. Vukovich MD, Stubbs NB, Bohlken RM, Desch MF, Fuller JC, Rathmacher JA (1997) The effect of dietary HMB on weight gains and body composition changes in older adults. FASEB J 11.3: A376.