I mixed equal parts water and vinegar in a glass and put tablet in this morning at 9:30 am CST. Now, many doctors, nutritionists, health care providers, etc. will tell you they often see undigested vitamin supplements on x-rays of people's stomach or colon. And I'm going to confirm that they are right and people are probably wasting millions of dollars per year on this stuff.

But what are effects relating to fitness? If that grande-no-foam-double-whipped-extra-shot-no-fat latte gives us get-up-and-go to start our day at work, will it do same if we’re headed to gym?

Physiological Effects The main ingredient in coffee that gives us that jolt is caffeine, a central nervous system stimulant. Caffeine is found naturally in coffee beans, tea leaves, and chocolate, and is a popular added ingredient in carbonated beverages and some over-the-counter medications such as cold remedies, diuretics, aspirin, and weight control aids. It is estimated that in U.S., 75% of caffeine intake comes from coffee.

Caffeine stimulates central nervous system by blocking adenosine, a neurotransmitter that normally causes a calming effect in body. The resulting neural stimulation due to this blockage causes adrenal glands to release adrenaline, "fight or flight" hormone. Your heart rate increases, your pupils dilate, your muscles tighten up, and glucose is released into your blood stream for extra energy. Voila… you now have caffeine buzz.

But wait…we’re not done yet. Caffeine also increases dopamine. Dopamine activates pleasure in parts of brain. It has been suspected that this also contributes to caffeine addiction.

Physiologically, caffeine makes us you feel alert, pumps adrenaline to give you energy and changes dopamine production to make you feel good. Another espresso, anyone?

Ergogenic Effects of Caffeine to Performance In addition to various psychological and physiological benefits, numerous studies have documented caffeine’s ergogenic effect on athletic performance, particularly in regard to endurance. Studies show that caffeine ingestion prior to exercising extended endurance in moderately strenuous aerobic activity. Other studies researching caffeine consumption on elite distance runners and distance swimmers show increased performance times following caffeine consumption.

Despite effects on endurance, caffeine produced no effect on maximal muscular force in a study measuring voluntary and electrically stimulated muscle actions. However, same study did show findings that suggest caffeine has an ergogenic effect on muscle during repetitive, low frequency stimulation.

Caffeine’s positive performance-enhancing effects have been well documented. So much so that International Olympic Committee placed a ban leading to disqualification for an athlete with urinary limits exceeding 12 mg/mL. Roughly 600 to 800mg of caffeine, or 4 to 7 cups of coffee, consumed over a 30-minute period would be enough to exceed this level and cause disqualification. The National Collegiate Athletic Association has a similar limit, set at 15 mg/mL.