Caffeine & Strength

Exercise is important for looking and feeling your best, and many studies show its remarkable benefits in reducing your risk of chronic illnesses and serious disease. In fact, strength training has been linked to reduced risk of injury and osteoporosis by increasing bone density while improving stamina, focus and weight loss. Interestingly, the cup of coffee you have each morning may do more than wake you up. It may improve your health by benefiting your gym session. A number of studies have looked at the ergogenic, or performance-boosting, effects of caffeine during exercise.

Caffeine

Caffeine helps you feel more alert by stimulating the nervous system, but when taken in excess, it can have some negative effects, including restlessness and anxiety. Most people get their caffeine fix in their morning cup of joe, which research has shown is full of free-radical-fighting antioxidants. Studies link coffee's protective health benefits to reducing risk of heart disease, stroke, Parkinson's, liver cancer and cirrhosis, and type 2 diabetes.

Strength Training

Strength training is the use of body weight or equipment such as free weights, weight machines and resistance tubing to increase muscular strength. It preserves and enhances lean muscle mass, while encouraging body fat loss. In a 2008 study published in the "Journal of Strength and Conditioning Research," consuming caffeine an hour before a strength training session improved study participants' performance in both leg extension and arm curl exercises. However, researchers noted that individual results varied greatly, indicating that further research is needed into the exact mechanisms by which caffeine affects performance.

Athletic Performance

During exercise, your muscles burn glycogen as a primary fuel. Your muscles begin to burn fat as fuel when glycogen is depleted. Caffeine appears to mobilize fat stores so that your muscles use as much as 50 percent less glycogen at the beginning of your exercise session, increasing endurance. Studies reflect that caffeine primarily benefits aerobic exercise performance by prolonging duration. However, a 2009 study published in the journal "Sports Medicine" indicated that caffeine appears to have some value in strength training because of its direct effect on the central nervous system and dampening pain perception during exercise to allow a more sustainable and forceful muscle contraction.

Negative Effects of Caffeine on Strength Training

Some research, including a 2010 study published in the "Journal of Sports Science and Medicine," indicates that caffeine may negatively affect resistance training. In the study, caffeine appeared to reduce production of human growth hormone and increase levels of cortisol. Cortisol is a catabolic hormone that can inhibit protein synthesis and degrade muscle protein. These negative changes in anabolic hormonal response may inhibit muscle growth. However, the exact mechanism by which caffeine creates these changes is unknown, and further research is indicated.