In order to build muscle, you have to be in a positive nitrogen balance. One supplement that claims to help augment nitrogen balance is HMB
, known as
. HMB is a metabolite of
, one of the
branched chain amino acid
s. Prior work with HMB has provided some evidence for a nitrogen sparing effect. A recent study in the Journal of Trauma investigated whether HMB could offset the negative nitrogen balance in critically ill patients who were admitted to the hospital for acute trauma. Initially, 100 patients were randomly assigned to receive for two weeks either HMB (3 g/day), HMB + extra arginine and glutamine (14 g/day each), or a control that had equal amounts of protein. While in the hospital, measures of nitrogen intake and nitrogen excretion were made in order to calculate nitrogen balance. Because of the acute trauma, nitrogen balance declined rapidly during the initial week of treatment in all groups. However, during the second week of treatment, the HMB
groups exhibited a more rapid recovery in nitrogen balance, meaning they were in a less negative nitrogen balance. There did not appear to be any advantage to the extra arginine and glutamine beyond that achieved with HMB alone. These findings indicate that HMB may provide some benefit on protein balance in severely catabolic situations such as trauma. Although not exactly the situation for athletes, frequent very high intensity training can be viewed as a form of trauma, especially if associated with inadequate rest and recovery.
Kuhls DA, Rathmacher JA, Musngi MD, Frisch DA, Nielson J, Barber A, MacIntyre AD, Coates JE, Fildes JJ. Beta-hydroxy-beta-methylbutyrate supplementation in critically ill trauma patients. J Trauma. 2007 Jan;62(1):125-31; discussion 131-2.