How Top Athletes Beat the Heat.

Summer can be especially exhausting for athletes. Recovery is often more difficult, because hot workouts cause more fluid and electrolyte loss, as well as an increase in core temperature, said Ben Greenfield, one of the nation’s top fitness, triathlon, and nutrition experts.

Greenfield was voted in 2008 as the Personal Trainer of the Year by the National Strength and Conditioning Association and recently wrote the “Get Fit Guy’s Guide to Achieving Your Ideal Body.” He said to enhance recovery, athletes should take a cold shower or ice bath directly after a workout, followed by an Epsom salt bath a few hours later or even the next day.

“If I’m sore post-workout, or after a long weekend of training, I’ll draw a bath and throw a few cups of Epsom salt in to help relax the muscle, decrease swelling and inflammation, and speed up recovery,” Greenfield said.

After athletes have a chance to cool, Greenfield recommends adding 2 to 3 cups of Epsom salt to a bathtub with water about 100 to 103 degrees (not too hot, since that can limit the absorption of Epsom salt — actually magnesium sulfate — which researchers have found can be absorbed through the skin).

Epsom salt baths can also be used to deal with lingering tightness or injuries that may be holding some out of summer training, said Greenfield, who has a BA and MA from the University of Idaho in sports science and exercise physiology and personal training, plus strength and conditioning certifications from the NSCA.

Every muscle operates via a fine electrochemical balance, Greenfield said. The electrolytes in Epsom salt can help to displace some of the charges across the muscular membrane, particularly those from calcium, which he said causes a contracted muscle to relax.

Greenfield also said foot soaks can help after long runs, or for athletes battling any type of plantar fascia or Achilles pain. To do that, he’d add 1/2 cup of Epsom salt to a large pan of warm water, and soak the feet for 10 to 15 minutes, followed by rinsing and drying. In general, though, he prefers baths.

“Go big,” Greenfield says, “or go home.”

Note: For human use, the Epsom Salt Council recommends only Epsom salt with the USP designation.