When it comes to exercise, you get out what you put in. So, when you devote a lot of work, you expect fabulous results. But, sometimes, the results of a workout are far from what was expected.
From surprise orgasms to black toes, a number of strange things can happen to the body when put through its paces. These issues often occur when the exercise is intense, when it lasts a long time and is atypical -- running a marathon, for example.
Many of the problems stem from simple nutrient depletion, as the body uses up fuel to sustain a tough work out.
"When the body is stressed, it reroutes resources, such as blood flow, away from non-vital systems," said Dr. Michelle Wolcott, assistant professor and sports medicine specialist at the University of Colorado at Boulder. "Muscles, particularly the heart and leg muscles, use up all available nutrients and oxygen."
Because of this, loading up on electrolyte salts or carbohydrates for energy won't solve the problem, and a person can go into a state of hyponatremia, in which the body cannot even process any nutrients.
Marathon and long distance runners seem to endure the bulk of odd side effects from physical exertion, although almost any activity done to excess can have adverse effects, from weight lifting to sports.
In general, however, weird phenomena resulting from intense exercise are out of the ordinary. It is rare that the average gym-goer would experience these problems.
"It's a distinct minority [of people] with a personality type that is probably very different," said Dr. Linn Goldberg, professor of medicine and head of the Division of Health Promotion and Sports Medicine at Oregon Health and Sciences University in Portland.
People who are adversely affected by a hard workout also often have underlying problems, such as a history of migraines, that make them susceptible to further issues.
Experts say the best way to exercise without side effects is to do it often, build intensity slowly and maintain proper nutrition.
"A little can be good, a lot does not mean it's better," Goldberg said.
The following is a list of some of the strange things that happen to the body during exercise.
Mystery or not, the female orgasm has an infinite capacity to surprise. The latest: orgasms making an appearance at the gym.
A phenomenon hotly debated on Internet message boards, many women claim to have orgasms while exercising, primarily during core muscle work, giving it the moniker "coregasm."
Crunches, hanging leg raises and other moves that tense and relax muscles surrounding the pelvis and the pelvic floor muscles seem to be the best triggers for coregasms.
"Orgasm is a physiological response," said Bean Robinson, associate director of the Program in Human Sexuality at the University of Minnesota Medical School. "We know some women who can have orgasms without any physical stimulation, just mental stimulation. ... It makes perfect sense to me that someone could have an orgasm [while exercising.]"
In addition, the pleasure hormones -- endorphin and dopamine -- that are released during exercise may contribute to coregasms.
But the phenomenon may still be rare enough to render the medical community skeptical. Few men have come forward with the same experience.
"I don't know of any science that supports that," said Dr. Ann Hoch, associate professor and director of the Women's Sports Medicine Program at the Medical College of Wisconsin.