Short-term beta-hydroxy-beta-methylbutyrate supplementation does not reduce symptoms of eccentric muscle damage.
OBJECTIVE
We examined the effects of short-term beta-hydroxy-beta-methylbutyrate (HMB) supplementation on symptoms of muscle damage following an acute bout of eccentric exercise.


METHODS
Non-resistance trained subjects were randomly assigned to a HMB supplement group (HMB, 40mg/kg bodyweight/day, n = 8) or placebo group (CON, n = 9). Supplementation commenced 6 days prior to a bout of 24 maximal isokinetic eccentric contractions of the elbow flexors and continued throughout post-testing. Muscle soreness, upper arm girth, and torque measures were assessed pre-exercise, 15 min post-exercise, and 1, 2, 3, 4, 7, and 10 days post-exercise.


RESULTS
No pre-test differences between HMB and CON groups were identified, and both performed a similar amount of eccentric work during the main eccentric exercise bout (p > .05). HMB supplementation had no effect on swelling, muscle soreness, or torque following the damaging eccentric exercise bout (p > .05).


CONCLUSIONS
Compared to a placebo condition, short-term supplementation with 40mg/kg bodyweight/day of HMB had no beneficial effect on a range of symptoms associated with eccentric muscle damage. If HMB can produce an ergogenic response, a longer preexercise supplementation period may be necessary.
Paddon-Jones
D
D
School of Human Movement Studies at The University of Queensland, Brisbane, Australia. djpaddon@utmb.edu
Keech
A
A
Jenkins
D
D
D000328:Adult; D001132:Arm / Q000033:anatomy & histology; D019587:Dietary Supplements; D004311:Double-Blind Method; D004551:Elbow Joint / Q000502:physiology; D015444:Exercise / Q000502:physiology*; D006801:Humans; D007537:Isometric Contraction; D008297:Male; D018482:Muscle, Skeletal / Q000293:injuries* / Q000378:metabolism / Q000473:pathology; D011897:Random Allocation; D013997:Time Factors; D019415:Torque; D014631:Valerates / Q000008:administration & dosage*
D014631:Valerates; C004961:beta-hydroxyisovaleric acid