Testosterone Responses to Intensive, Prolonged Endurance Exercise in Women

OBJECTIVE: To examine the response of testosterone in women to an intensive, prolonged endurance exercise bout that mimicked a competitive event. METHODS: Ten healthy eumenorrheic women ran to exhaustion at ~100% of their ventilatory threshold in their follicular menstrual cycle phase. Testosterone measures were assessed pre-exercise, immediately, 30 min, 60 min, 90 min, and 24 h post-exercise. RESULTS: At exhaustion (75.1 ± 7.0 min), total (56%), free (36%), and bioavailable testosterone (50%) were increased from pre-exercise values (p< 0.05). At 24 h post-exercise, these measures were decreased from pre-exercise values (−21%, −31%, −18%, respectively; p < 0.05). Effect sizes for these changes ranged from medium to large in magnitude. CONCLUSION: Testosterone was elevated in the early recovery period following exhaustive endurance exercise but was reduced by 24 h afterward. These outcomes are comparable to responses seen in men when sex-based concentration differences are considered.