BACKGROUND: Methylsulfonylmethane (MSM) has been reported to provide 
anti-inflammatory and antioxidant effects in both animal and man. Strenuous 
resistance exercise has the potential to induce both inflammation and oxidative 
stress. Using a pilot (proof of concept) study design, we determined the 
influence of MSM on markers of exercise recovery and performance in healthy men.
METHODS: Eight, healthy men (27.1 ± 6.9 yrs old) who were considered to be 
moderately exercise-trained (exercising <150 minutes per week) were randomly 
assigned to ingest MSM at either 1.5 grams per day or 3.0 grams per day for 30 
days (28 days before and 2 days following exercise). Before and after the 28 day 
intervention period, subjects performed 18 sets of knee extension exercise in an 
attempt to induce muscle damage (and to be used partly as a measure of exercise 
performance). Sets 1-15 were performed at a predetermined weight for 10 
repetitions each, while sets 16-18 were performed to muscular failure. Muscle 
soreness (using a 5-point Likert scale), fatigue (using the fatigue-inertia 
subset of the Profile of Mood States), blood antioxidant status (glutathione and 
Trolox Equivalent Antioxidant Capacity [TEAC]), and blood homocysteine were 
measured before and after exercise, pre and post intervention. Exercise 
performance (total work performed during sets 16-18 of knee extension testing) 
was also measured pre and post intervention.
RESULTS: Muscle soreness increased following exercise and a trend was noted for 
a reduction in muscle soreness with 3.0 grams versus 1.5 grams of MSM 
(p = 0.080), with a 1.0 point difference between dosages. Fatigue was slightly 
reduced with MSM (p = 0.073 with 3.0 grams; p = 0.087 for both dosages 
combined). TEAC increased significantly following exercise with 3.0 grams of MSM 
(p = 0.035), while homocysteine decreased following exercise for both dosages 
combined (p = 0.007). No significant effects were noted for glutathione or total 
work performed during knee extension testing (p > 0.05).
CONCLUSION: MSM, especially when provided at 3.0 grams per day, may favorably 
influence selected markers of exercise recovery. More work is needed to extend 
these findings, in particular using a larger sample of subjects and the 
inclusion of additional markers of exercise recovery and performance.