Mittwoch, 3. Juli 2013

Science: Post-Resistance Exercise Ethanol Ingestion and AcuteTestosterone Bioavailability

Alcohol (ethanol) and resistance exercise can independently affect circulating bioavailable testosterone concentration. PURPOSE: The purpose of this study was to examine the testosterone bioavailability and the anabolic endocrine milieu in response to acute ethanol ingestion following a bout of heavy resistance exercise. METHODS: Eight resistance trained men (mean +/- SD: 25.3 +/- 3.2 yrs, 87.7 +/- 15.1 kg, 177 +/- 7 cm) completed two identical acute heavy resistance exercise tests (AHRET: six sets of 10 repetitions of Smith machine squats) separated by 1 week. Post-AHRET participants consumed either 1.086 g of grain ethanol per kg lean mass (EtOH condition) or no ethanol (Placebo condition). Blood samples were collected immediately before exercise (PRE), immediately after exercise (IP), and every 20 min postexercise for 300 min. Samples following IP were pooled into phases (20-40 min, 60-120 min, and 140-300 min after exercise) and analyzed for total (TT) and free testosterone (FT), sex hormone binding globulin (SHBG), cortisol, and estradiol. RESULTS: Peak blood ethanol concentration (0.088 +/- 0.015 g[middle dot]dl-1) was achieved 60-90 min post-exercise. TT and FT was elevated significantly (p<=0.05) at IP for both conditions. At 140-300 min post-exercise TT, FT, and free androgen index were significantly higher for EtOH (TT: 22.5 +/- 12.5 nmol[middle dot]l-1 ; FT: 40.5 +/- 7.6 pmol[middle dot]l-1) than for Placebo (TT: 13.9 +/- 6.8 nmol[middle dot]l-1; FT: 22.7 +/- 10.0 pmol[middle dot]l-1). No differences between conditions were noted for SHBG, Cortisol, or Estradiol. CONCLUSION: Post-exercise ethanol ingestion affects the hormonal milieu including testosterone concentration and bioavailability during recovery from resistance exercise.