The 3 Keys of an Effective Training Nutrition Plan

Anytime you're training for more than 60 minutes, I recommend hydrating during training, from at least the 30-minute mark onward. If you're training for 60 minutes or less, you can likely get by with no hydration as long as you're well-hydrated going into training. Or, you can take along water.

More: 6 Ultrarunning Hydration Gear Options

In high heat or humidity, you must hydrate while training—no matter the duration. But, what about over-hydration? I'll cover this below in the electrolyte section. Over-hydration is really too little electrolytes compared to the amount of fluid intake. It's not the fluid that's the problem, but the lack of electrolytes.

Within each goal group, there's subtle difference in my fluid recommendations.

Weight Loss	Performance	Competitive
Fluid Needs: 18-24 oz. fluid per hour (runners may carry slightly less, but aim for at least 75% of these amounts)	Fluid Needs: Follow the weight-loss guidelines.	Fluid Needs: Follow the weight-loss guidelines.
Drink choices: Electrolyte tabs in water.	Drink choices: < 90 minutes: Electrolyte tabs in water. 90 minutes or >: Full Nutrition drinks with 10-15 grams carbs per 8 oz.	Drink choices: < 90 minutes: Follow the performance guidelines. 90 minutes or >: Follow the performance guidelines.
Comments: Although you may not want sugar and carbs, the electrolytes and fluids are still important.	Comments: If you choose to use a low-carb or diluted drink, make up for the carbs in other fuel sources.	Comments: If you're training or competing for 5+ hours, aim for more carbs per hour.

Quick Tip: Want to know exactly how much fluid you need during training? Weigh yourself immediately before and after training, in the buff or in only underwear, if possible. If not, have on the same clothes both times. Calculate every pound lost as 16 fluid ounces. Then, add in any fluid you consumed during training. This is the amount of fluid you lost during that specific exercise session. Plan to hydrate proactively for the next one.

More: Hydration Guide for Endurance Athletes