John Underwood from the American Athletic Institute is world-renowned for his expertise and research on athletic performance. Underwood works extensively with Olympic athletes including both World and Olympic champions. Underwood’s work and research highly revolves around the impact that drugs and alcohol take on the body and performance of an athlete.

Underwood surveyed 215 high school athletic directors and found that 59% of them had personally death with intoxicated student-athletes. He found that alcohol use was more prominent in high school athletes than the use of other drugs. The following are facts that Underwood and his team of researchers have discovered while exploring the impact of alcohol on athletic performance:

  • Alcohol increases the time for recovery of androgenic training hormones by up to 96 hours;
  • Alcohol’s diuretic effect diminishes water soluble vitamins required for hormone catalytic/conversion actions;
  • Alcohol increases the release of cortisol (the stress hormone).  Cortisol negates training effect;
  • Alcohol decreases the protein synthesis for muscle fiber repair;
  • Alcohol reduces the immune system capability;
  • Alcohol reduces performance potential by up to 11.4%;
  • Alcohol disturbs the REM (rapid eye movement) time reducing the CNS (central nervous system) restorative/recovery ability;
  • Alcohol impairs reaction time up to 12 hours after consumption;
  • Heavy episodic drinking results in projected loss of up to 14 days of training effect;
  • Alcohol affects heart lungs and muscle performance


Source: American Athletic Institute. (2006). Pure performance: The way to success. Retrieved from