I also had problems with the heat when I hiked three weeks ago on a Sunday. I left at 6 AM and hit the tram at 1 PM. When I hit the trees, I literally laid down in the middle of the trail to let my core temperature cool off. I'm glad none of you stepped over my body that day
Shameless plug for Cactus2Clouds Perry -- thank you for your website and this forum. I discovered the site after that hike.
I've had muscle cramps on this hike at Flat Rock and can attest that they're awful.
Heat cramps are caused by an imbalance of the body's water and electrolyte (primarily sodium) concentrations. Heat cramps are caused by losing too much fluid (dehydration) and/or loosing too much sodium from sweating. Some athletes are salty sweaters (sweat stings the eyes and clothes are covered with salt) and are at greater risk of heat cramps.
If you drink enough fluid to nearly replace your sweat losses and still cramp, you probably need more sodium. I recommend consuming about 800 milligrams of sodium for every 2 lb (1 quart) of sweat lost.
There are many ways to replace sweat sodium losses during endurance exercise (I provide these guidelines for triathletes but they're also appropriate for hikers):
1) Use a sports drink with a higher sodium content such as Gatorade Endurance or PowerBar Endurance. One qaurt of Gatorade Endurance has 800 mg of sodium.
2) Use a carbohydrate gel with a higher sodium content such as some of the PowerBar gels. PowerBar gels that have 4X sodium provide 200 mg per gel.
3) Use a low dose (300 to 500 mg) sodium tablet every 1 to 2 hours.
4) Carry those little salt packets from fast food restaurants. One half teaspoon of salt has 1000 mg of sodium. I believe the packets have a 1/4 teaspoon of sodium (500 mg).
5) Check out E-lyte or Hydrolite (per Guest's earlier post)
6) Carry salty snacks such as pretzels and baked chips.
If you drink water or other low-sodium fluids, consider options 2-6.
Heat cramps can be avoided by staying hydrated and consuming enough sodium.
Don't over-drink. If you drink more fluids than you're losing in sweat, you can dilute the sodium level in your blood and develop hyponatremia (low blood sodium). This causes brain swelling and associated symptoms. Hyponatremia usually occurs in endurance events lasting 4 hours or more. There are case studies of Grand Canyon hikers developing hyponatremia. It has also been observed in long runs and triathlons.
If you gain weight after a long hike, you're overdrinking.
Bottom line -- drinking too little or too much fluid can be dangerous.
Miles of smiles,
Ellen