Hydrate
When exercising, you lose about a litre of water per hour—a figure that increases with heat and humidity. Drink a minimum of 400 millilitres per hour to stave off dehydration. But avoid drinking more than a litre per hour; it will only slosh around in your stomach. While water will get you through most workouts, those exceeding 90 minutes require more than H2O. When you're getting a serious sweat on, stick to the following sipping schedule.
 
Before exercise: Drink 500 millilitres of water two hours before, and 250 millilitres an hour before. This will hydrate you, but also give you enough time to go to the washroom beforehand.

During  exercise: Aim for at least 400 millilitres per hour. If you're going for more than 90 minutes, switch from water to a sports drink. These drinks contain electrolytes like sodium and potassium (which are lost when you sweat), and carbs for energy. Sip slowly to avoid stomach cramps.

After exercise: Try chocolate milk—it has the perfect ratio of carbs to protein needed for recovery. During exercise, carbs help maintain glucose levels, but afterward they restore glycogen, a form of energy stored in the muscles. That energy, combined with muscle-repairing protein, will prepare you for your next workout.

Fuel
During endurance exercise, you need more than just fluids to keep you going. If you're spending a short time at the gym, there's no need to completely change your eating habits, but if you're active for more than 90 minutes, you'll want to pay careful attention to how you're fuelling your body. Follow this eating itinerary.

Before exercise: Eating too close to your workout can cause poor performance and uncomfortable cramping, as digestion draws blood to the digestive system and away from muscles. Try to wait two to three hours after a meal or one hour after a snack to get moving, particularly if you're doing an activity like running, in which your body bounces up and down. Focus on light protein and complex carbs to provide a slow release of energy as you exercise. For a meal, try chicken and quinoa; for a snack, try toast with peanut butter.

During exercise: While some people might be OK with a sports drink for long periods of physical activity, others may find they need something more. Fruit and protein bars are easy options that can keep you going. If you're buying a protein bar, look for whole foods on the ingredient list, such as dried fruits, nuts, seeds and whole grains. Or use those foods to make your own bars. Runners might want to stick with quick-digesting carbs like fruit or sport gels, while cyclists may be able to stomach more solid foods, like sandwiches.

After exercise: Getting the proper nutrients after a workout helps your body recover. Try a smoothie consisting of protein and carbs. Include berries (for carbs), a banana (for carbs and potassium), whey powder (for easily absorbable protein) and milk (for protein and hydration). Have a couple of crackers on the side for sodium, and avoid fats during recovery, as they'll slow down absorption.

Drinking water and still getting muscle cramps?
Those cramps are signs of a fluid imbalance in your muscles' cells. Drinking water should relieve cramps. If it doesn't, that's a sign you also need to replenish your electrolytes. Try a sports drink or vegetable juice; both contain electrolytes like sodium and potassium, which help control the body's fluid balance. 

What's your sweat rate?
We all perspire differently, so it's important to know how much you sweat during an average workout to avoid dehydration. Weigh yourself before and after exercise. If you've lost more than two percent of your body weight, you're dehydrated and need to step up fluid intake during your workouts.

Need some caffeine?
Caffeine is added to some sports drinks, but it's not just for an energy boost. Erdman says caffeine dulls the perception of pain, so you can keep going when you're not feeling your best. 

Working on your muscles?
If you're doing strength training, your meal before and after working out should consist of two parts carbs to one part protein. For cardio, aim for a three to one ratio of carbs to protein. And don't overdo the protein: Erdman says the most your body can use at a time is 30 to 35 grams, the equivalent of about a cup of Greek yogurt.

Worried about sugary drinks?
The sugar in sports drinks can send up red flags. But when you're working hard for more than 90 minutes, the sugar is OK. Erdman says you won't get blood-sugar spikes because insulin is suppressed during exercise.

Trying to lose weight?
Feel free to reduce the amount of food you consume in recovery, but don't cut it out entirely. Neglecting to nourish your muscles after a big workout will leave you with only half a tank of energy for your workouts in the days that follow, and may leave you with some intense cravings.

For more fitness tips, check out the 4 best workouts for burning calories.
 

This content is vetted by medical experts

                                               

This story was originally titled "Power Up" in the June 2014 issue.             Subscribe to Canadian Living today and never miss an issue!