Strategies for Enhancing Exercise
Hormone Restoration (Men and Woman)
Age-related decline in levels of testosterone and growth hormone are associated with loss of muscle mass and strength, exercise capacity, and mobility in elderly men. In addition, aging is associated with accumulation of body fat and insulin resistance.105 Diminished muscle mass and strength in the elderly are also accompanied by the rapid age-related decline in the hormone DHEA (dehydroepiandrosterone).106
Testosterone and growth hormone are potent anabolic (tissue-building) agents that increase muscle mass, but they act through different mechanisms. The combination of testosterone and growth hormone has a greater anabolic effect than either hormone alone. In fact, studies in healthy older men have shown that hormone replacement therapy (HRT) with a combined regimen of testosterone and growth hormone, but not either one alone, increased exercise capacity and muscle strength.
Collectively, these studies indicate treatment with moderate doses of testosterone and growth hormone is safe over a six-month period.105 However, long-term use of growth hormone therapy may increase the risk of some cancers.107 People at risk for cancer should consult a healthcare provider before initiating growth hormone therapy, and long-term use may be unwise.
For more information about HRT, see Life Extension's Male Hormone Restoration protocol.
In women, HRT using estrogen and progesterone may also enhance the effects of exercise. In one study, post-menopausal women using conventional HRT had significantly greater improvements in exercise-induced insulin sensitivity than post-menopausal women not using HRT.108
Bioidentical hormone replacement therapy (BHT)—including progesterone, estradiol, and estriol—has become a popular alternative to traditional HRT for the treatment of menopausal symptoms. Bioidentical hormones are structurally identical to human hormones.109-111
Data from a review of studies found the use of bioidentical hormones carries a lower risk of breast cancer and cardiovascular disease, and treatment with BHT has been as effective as conventional HRT for the treatment of menopausal symptoms.112,113 For more information on BHT, see the Life Extension's Female Hormone Restoration protocol.
Proper timing of meals can enhance exercise capacity and aid recovery and tissue repair following exercise.114-116
Consuming a carbohydrate-containing meal four to six hours before exercise ensures adequate reserves of glycogen (stored carbohydrate energy) in muscle and liver. An additional carbohydrate plus protein snack, consumed 30 to 60 minutes prior to exercise, may protect against energy depletion towards the end of an intense exercise session, as well as help prevent breakdown of protein in muscle tissue.115
During prolonged intense exercise (ie, greater than 60 minutes), beverages (10‒15 fl. oz.) containing carbohydrate and electrolytes should be ingested every 15–20 minutes to prevent low blood sugar levels.115
Post-exercise nutrition is important to help replenish glycogen stores and repair muscle tissue damaged during exercise. The International Society for Sports Nutrition recommends protein and carbohydrate consumption within three hours after exercise.115,117
Elderly individuals may require greater post-exercise protein intake to maximize recovery.117 One study showed 20 grams of post-exercise supplemental protein maximally stimulated muscle protein synthesis in young men118; another study found that in elderly men, 40 grams of post-exercise whey protein enhanced muscle protein synthesis more than 20 grams of whey protein.119
Studies suggest caffeine ingested before or during exercise enhances endurance exercise performance. Emerging research also suggests caffeine aids in short-term, high-intensity burst activity performance. For example, competitively trained males who ingested 5 mg/kg body weight of caffeine lifted more total weight on the chest press and generated greater anaerobic power.120 This dose of caffeine corresponds to about 2‒4 cups of coffee for a 170-pound individual.121,122 Approximately 150 to 300 mg of caffeine, or about one to three cups of coffee, has been shown to improve concentration and decision making during and after exhausting exercise.121
Possible mechanisms for the ergogenic effects of caffeine include increased fat burning, reduced fatigue, central nervous system stimulation, and reduced perception of pain.121,123,124 The stimulant effect of caffeine is primarily due to its ability to block adenosine receptors in the brain.125,126
Possible side effects of caffeine consumption include increased heart rate, disturbed sleep, and nervousness; these are generally less pronounced with lower doses.121 The response to caffeine varies considerably from person-to-person.127-129 A recent review suggested older adults may be more susceptible to the sleep-disrupting effects of caffeine than younger individuals, so awareness of sleep quality and modifying caffeine use appropriately is important.130