Acromegaly patients, who suffer from natural growth hormone levels of up to 100 times higher than normal, have lower stamina towards physical activity than people with regular levels.  When the patients are treated and their growth hormone levels decrease, their stamina improves.  This knowledge is part of the evidence behind the new belief that athletes who use supplemental HGH to raise their levels far above average could actually decrease their exercise tolerance, and thus hurt their athletic performance.  Further backing was provided in a study done by the Danish Institute of Sports Medicine. They found cyclists of good health and endurance “were unable to complete accustomed cycling tasks after administration of exogenous hGH” and concluded that HGH can inhibit recuperation from exercise.  Participants have also been found to have lower stamina after HGH treatment along with higher rates of fatigue. 
Foods high in amino acids may also bump up HGH production in your body. Your basic protein-packed meats (such as chicken, beef, pork, and fish) are good places to start, and dairy products (such as milk, cheese, and yogurt) can also provide the nutrition you need to encourage HGH secretion. A 2008 study published in the Journal of the International Society of Sports Nutrition reported that choline, a neurotransmitter, may boost production of growth hormone, so be sure to add foods that are high in choline, such as eggs and shrimp, to your training table.