Taking a daily L-arginine supplement for two weeks might help young men recover faster from bike workouts by reducing a chemical in their blood that signals muscle damage.

A randomized, double-blind, placebo-controlled trial in healthy young men comparing chronic L-arginine (5 g/day for 14 days) vs. placebo, with serum CK measured before, immediately after, and at 24, 48, and 72 hours post-cycling exercise.

A crossover trial in healthy young men comparing chronic L-arginine (5 g/day for 14 days) vs. acute L-arginine (single 5 g dose on exercise day) vs. placebo, with serum CK measured at multiple time points post-cycling.

A prospective cohort study tracking serum CK changes in healthy young men who self-select into chronic L-arginine (5 g/day for 14 days) or placebo groups, with standardized cycling and CK measurements.

A case-control study comparing serum CK levels after cycling in healthy young men who chronically use L-arginine (5 g/day for ≥14 days) vs. those who do not.

A small pilot study measuring serum CK and other muscle damage markers (e.g., myoglobin, IL-6) in healthy young men after chronic L-arginine supplementation and cycling to explore biological plausibility.