Learn how (and when) to fuel your body for cardio and strength workouts.
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The secret to weight loss is consistency in healthier food choices and habits, but there are other components that can help you reach that goal quicker, like exercise.

Research suggests that those who engage in regular physical activity are 1) more likely to have success in losing weight , and 2) more likely to keep that weight off down the road. Exercise also enhances body composition by decreasing fat mass and increasing lean body mass, which gives metabolism a little boost, along with other health benefits like improvements in insulin sensitivity, blood pressure, blood lipids, mental outlook, stress management, and sleep.

Combining weight loss with working out can get tricky when it comes to food. Fueling your workouts while trying to lose weight requires a careful balancing act. On one hand, you need adequate fuel and hydration to support activities. On the other, you don’t want to stall weight loss efforts by overcompensating with that fuel. Here's how to strike a balance between fueling your workouts and reaching your weight loss goals.

Do I need to fuel up for workouts?

The first step is to determine if pre-workout fuel — foods, drinks, or supplements — is really needed. Many people who eat a nutrient-dense diet that meets their energy needs don't need extra fuel to exercise at moderate intensity for 60 minutes or less.

This is often true with low to moderate intensity activities that last a little longer than 60 minutes as well. But determining exact needs depends on the health and adequacy of the diet plan, exercise duration and intensity, and the individual.

An ideal diet plan that supports both weight loss and workouts is one that provides calories that aren’t significantly below estimated needs through nutrient-dense foods like produce, lean proteins, healthy fats, and complex carbs like beans and whole grains.

How many calories should I eat before a workout?

The key is learning to listen to your body and decipher what it’s telling you. Adequately fueled workouts should leave you feeling a little tired and sweaty, but, overall, refreshed and energized. If not, this is often a sign that the body needs more fuel by increasing total daily calories or adding a pre-workout snack.

If you need a little extra fuel, try changing up the eating times of the foods you’re already consuming (more instruction on this below). Then, if needed, add additional fuel — generally a snack or small meal of 150 to 350 calories.

Before I go further, I want to emphasize that the tips and recommendations provided in this article are for individuals exercising within the activity guidelines mentioned above, and who are also following a healthy diet and/or weight loss plan. They are not for individuals following very low-calorie diets (less than 1,200 total calories or more than 500 calories below estimated needs), those who have an existing nutrient deficiency, those who are working out longer or more strenuously than described above, or those who are underweight. In these situations, I recommend working with a dietitian one-on-one.

Eating before cardio and strength workouts

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  • Eat a small, energizing meal (or a larger snack) two to four hours before working out . The meal should be comprised largely of complex carbohydrates, some protein, and a little fat. For example: whole grain cereal with fat-free or low-fat milk, a turkey sandwich on whole grain bread, or low-fat Greek yogurt topped with berries and whole-grain granola.
  • Shift existing meals and snacks . “Fueling up” for a workout doesn’t always mean adding an extra meal or snack to your diet plan. Assuming you’re following a healthy diet and working out as described above, try moving the eating times of your regular meals. If you feel you need additional fuel on days you work out, then add that extra snack or small meal two to four hours prior.
  • Drink 20 to 32 ounces of water within four hours of working out . Avoid alcohol and minimize caffeinated drinks before doing cardio or strength training.
  • You may also want an easy-to-digest snack 45 to 60 minutes pre-workout . This should be a light snack of simple carbohydrates, like a banana, orange, or a snack bar. Try shifting one of your planned snacks (or part of one) first; then add if needed. Avoid foods high in fiber, protein, and fat to prevent GI distress.

Timing tips for eating before cardio-based workouts

You’ll quickly be able to tell if you aren’t getting adequate calories and carbs through your diet when doing longer, moderate to vigorous cardio activities, either by a lack of energy or changes in performance. Example: You can’t sustain the faster pace that seemed pretty easy a few days ago.

It’s important to listen to your body and consider cutting that cardio session a little short if needed. Then, make sure to consume a meal with complex carbs, protein, some fat, and plenty of water within one to two hours following. Consider a small snack before your next cardio session.

If you feel overly fatigued or think your diet may be affecting your workout, recall what you ate in the 24 hours leading to your workout. Did you consume significantly fewer calories or carbs than usual that day? Try shifting foods that have more calories and carbohydrates to be a pre-workout meal or snack two to four hours before working out. If this happens regularly, you probably need to consider increasing total daily calories and/or carbohydrates.

Timing tips for eating before strength training workouts

Protein is key for building lean body mass, but this doesn’t mean you need extra protein. If you’re following a healthy diet plan, then you’re likely consuming adequate daily protein amounts over the course of a day. Most research does not suggest additional protein beyond the recommended daily amount is needed unless you are an athlete or training for an event. Extra protein can be stored as fat just like carbs and fats.

Make sure you do consume a protein-rich meal or snack one to three hours post-workout. Athletes and those doing intense heavy lifting or training may need protein within a smaller time frame, but active individuals shouldn’t worry about precise timing.

It’s important to consume water the four hours prior, during, and after a workout, even if you’re working up less of a sweat.

A note about sports drinks and protein powders and bars

Hydration beverages like Gatorade or Powerade aren’t usually necessary for workouts lasting 60 minutes or less, and they can be a source of extra calories. Both fluids and electrolytes are adequately restored when you drink plain water, eat a healthy meal, or snack post-workout. However, these beverages can be helpful if workouts extend over an hour and/or involve excessive sweating.

Protein powders and bars are convenient at times, but you shouldn’t feel pressure to use them. It’s important to realize that 1) protein supplements aren’t superior to protein in food, and 2) they’re classified as dietary supplements and have little regulation when it comes to claims or ingredients. Remember, too, that most active people don’t need additional protein.