Electrolytes replace the salts your horse loses while sweating. If your horse is working hard and sweating profusely it may not be able to replace those salts through diet alone. What are electrolytes and when should they been administered?

And if you are working as hard as your horse is, you need to care for yourself too. A tired dehydrated rider can't look after its horse well. Wendy Bumgardner, About Guide to Walking mixes up some sports drink recipes you can make at home. Just don't share them with your horse!