HMB

What is HMB?

HMB (hydroxy beta methylbutyrate) is a derivative of the branched-chain amino acid leucine, which is formed in the body when leucine is metabolized. HMB plays an important role in protein metabolism in the human body and it is assumed that HMB also plays a significant role in the well-documented anabolic and anti-catabolic effects of leucine. Unfortunately, only about 5% of dietary L-leucine is converted into HMB in the human body, which corresponds to a daily production of just 1.5 grams of HMB in 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 body's ability to minimize protein breakdown in muscle cells under high stress, such as intensive training. 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, grapefruit 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, commissioned a group of students to feed a substance called -hydroxy -methyl butyrate to some sheep to see if it would increase meat production. A small amount of -hydroxy -methylbutyrate (HMB) was synthesized and they set 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 sporting world.

The tests on animals went so well that the application on humans was started. The results here were also stunning. Students who were given HMB and exercised at the same time gained muscle mass and lost fat - the ideal combination. Further studies followed and it soon became clear that HMB was not just a "fad", but a highly effective, natural means of increasing performance. According to insider reports, the majority of medal winners at the 1996 Olympic Games in Atlanta 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 quantities. HMB is therefore practically free of side effects. The latest research reports even suggest that HMB may also improve endurance performance. Even older people (in one study 65 - 80 year old test subjects were used) respond excellently to HMB! HMB is introduced into the muscle metabolism and influences 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 the skeletal muscles. 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 the breakdown of muscle mass, giving it a strong 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 intensive training session more quickly.

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

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

Furthermore, HMB increases protein efficiency, i.e. a protein diet 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 appears to have a particularly strong muscle-building effect on beginners and during the first few years of training. Dieting athletes can also benefit from HMB supplementation, as HMB effectively counteracts diet-induced muscle loss during a strict diet, while at the same time promoting fat loss. In addition to athletes and dieters, health-conscious people can also benefit from HMB supplementation, as HMB can lower blood pressure and levels of harmful LDL cholesterol, as well as stimulating 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. As creatine and HMB develop their effects via completely independent pathways, their individual effects add up when used in combination. In fact, studies have shown that subjects who combined creatine with HMB gained 30% more muscle mass than subjects who used creatine alone.

What are the main benefits of HMB?

• Has anabolic effects that promote muscle building
• Stimulates protein synthesis
• Can counteract diet-induced muscle loss through an anti-catabolic effect
• Protects muscle cells from training-induced damage and accelerates regeneration after training
• Supports the breakdown of body fat
• Delays exhaustion during training and increases aerobic and anaerobic endurance
• Reduces blood pressure and cholesterol levels
• Improves the function of the immune system

Recommended intake

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

Side effects

Apart from acne, there are no known side effects or intolerances, nor are there any acute risks of overdose. There are no studies on the risks of prolonged use. You should therefore be careful and consult your doctor if you notice any side effects associated with taking HMB. After all, HMB supplements have only been around since 1995, so the observations of effects and side effects to date are not conclusive. If you want to reduce protein breakdown in the body, you should definitely meet at least the minimum daily requirement of important nutrients (carbohydrates, fat, protein, vitamins, minerals, etc.).

Another thing, I have read in many reports of athletes who have not experienced any performance-enhancing effect from HMB intake. This indicates that they have not dosed optimally. With hardly any other supplement is the method of intake so decisive for the effect. If taken incorrectly, it does not help at all, and in the ideal dose it is one of the most effective supplements of 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 traning FASEB J. 10: A287.
2. Vukovich MD, Stubbs NB, Bohlken RM, Desch MF, Fuller JC, Rathmacher JA (1997) The effect of dietary HMB on strength gains and body composition changes in older adults. FASEB J 11.3: A376.