Ask A Dietitian: Should I Eat More Calories If I Workout?

This is an excellent question with multiple answers. Ultimately, the number of calories you should eat depends on a few factors. These include:

1. The goal of the workout. Training for an event? Trying to lose weight?

2. The duration of the work out. Going for a 20 minutes? Charging for 90 minutes?

3. The intensity of the workout. Is this a walk, intense run, cycle class, or athletic event?

Let’s dive into a few scenarios to better answer this question.

If you’re in for an intense session or going for the long haul yes, absolutely, you need more calories. Calories give you the energy to bust through your workout. Insufficient calorie intake will most likely lead to decreased performance and fatigue. Not getting in enough calories over time can lead to anemia, bone loss, muscle loss, menstrual dysfunction, injury, compromised immunity, decreased muscle mass, and decreased metabolism.

The amount of extra calories will depend on length of activity, intensity of activity, age, gender, and weight. A great website to calculate your calorie needs based on your activity level is This website gives you the tools to calculate your calorie needs for workout days and non-workout days.

To help you meet your calorie goal spread calories throughout the day and include pre- and post-workout snacks. Follow this simple guide to help you meet your caloric goal

Pre-workout: Have a carbohydrate rich snack 30-60 minutes beforehand. Avoid high fiber foods, artificial sweeteners, and high fat foods. These foods can cause an upset stomach during your workout. Good options include a Health Warrior Chia Bar, a slice of toast with jam, tart cherry juice, peanut butter and banana sandwich, yogurt with fruit, and apple with cheese.

The greater duration and intensity of the workout the more calories you will need. Use the below guide to help you estimate how large your pre-workout snack should be.

●      60 minutes of physical activity: 5-7g of carb per kg of body weight (1 kg = 2.2lb)

●      1-3 hours of physical activity 6-10g of carb per kg of body weight

●      4-5 hours of physical activity 10-12g of carb per kg of body weight

Post- Workout: To promote a speedy recovery, re-fuel within 1 hour of your sweat session. Choose a snack or meal that contains complex carbohydrates and protein. This will replenish glycogen stores, encourage muscle repair, and minimize muscle breakdown. Good options include a Protein Mug Muffin with almond butter and bananas, chia seed beet and berry smoothie, chickpea pasta with pesto, tofu quinoa stir-fry, and pea protein burger on a whole grain bun.

Going for a walk with a friend and chatting it up the whole time? Typically nope, you don’t need to add in extra calories. A casual walk likely won’t cause much of a calorie deficit that needs any conscious increase in calories.  If you’re able to have a conversation while you’re exercising you’re not working at a moderate activity level that would warrant additional calories. However, if this walk goes on for more than 60 minutes you could probably use an extra small snack during the day. Use the calorie calculator here to calculate how many calories you need depending on your duration of walk

Trying to shed a few lbs? When weight loss is part of the goal, many times, no you don’t need more calories. Generally low to moderate exercise under 60 minutes doesn’t need any additional fuel. When focusing on losing weight the goal is to burn more calories than you consume. Too big of a calorie deficit can cause you to lose weight too quickly which can cause a decrease in metabolism, hair loss, and decreased muscle mass. The goal is to lose about .5-2lbs per week, anything more than that is too much. If you are losing weight too rapidly (which may sound nice but it won’t help you long term) add in an additional calories on workout days. Some great options include Pumpkin Seed Bars, Chia Bars, an apple, a handful of raw almonds, chia seed pudding, avocado toast,

Bottom line, we have to look at the big picture and multiple factors to decide whether to boost calories on workout days or not. As always, fill your day with energy from nutrient dense foods and superfoods. Some of my favorite energizing foods include chia seeds, goji berries, blueberries, baru almonds, quinoa, pumpkin seeds, beets, sweet potatoes, flax seeds, walnuts, avocado, wild rice, acai, dark chocolate, tart cherries, strawberries, quinoa, and hemp seeds.