Hi Carrots āĖN’ Cake readers! My name is Nicole and I blog over at The Salted Kitchen, where I talk about nutrition, cooking, fitness and travel. I studied nutrition and dietetics in school, and rather than becoming a Registered Dietitian, I went a different route, and am now a food scientist at a large food company. I think my education and career offer two very distinctive views on the food world, and I love incorporating my passion for fitness and travel among it all.
I hope we have some science geeks out there, because today I’m going to discuss the science behind our post-exercise fuel needs. If you’re a Carrots āĖN’ Cake reader, I can assume you are physically active in one way or another. If you’re interested in improving your performance, it’s critical that you understand the proper way to refuel after exercise. You can increase endurance, strength and improve body composition, simply by fueling properly after exercise, and who wouldn’t want to do that?!
Understanding the Basics
First thing we need to understand is the difference between anaerobic and aerobic exercise. Anaerobic exercise is any activity that does not require oxygen, it’s high-intensity exercise that’s maintained for short durations of time. Sprints are a good example of anaerobic exercise. Aerobic exercise is activity that requires oxygen and can be maintained for long periods of time. Examples are running, cycling, or cross country skiing.
Another important term to understand before going forward is glycogen. When you eat carbohydrates, it enters your bloodstream as glucose, and is taken up in the muscles and liver as glycogen. Therefore, glycogen is the stored form of carbohydrates that is pulled for energy during exercise.
What Does Our Body Use for Fuel During Exercise?
Whenever we do any sort of activity, our body is using a mixture of fats, protein and carbohydrates for fuel. There is never a time when we are exclusively using only one or the other. This is why it’s so important that we maintain a balanced diet with all themacronutrients.
Depending upon the type and duration of exercise, you will use different ratios of these macronutrients. Protein is consistently providing about 10% of our energy during exercise – whether its anaerobic or aerobic. Glycogen is the primary source of fuel in any form of exercise. In aerobic exercise, the longer you maintain that activity, the more and more fat you will use for fuel, unless you replenish your available glucose. When aerobic athletes use up their glycogen supply (which is around 2000 calories worth), they need to provide available sources of glucose for immediate energy (sports drink, goo packets). If they don’t they will continue to use more and more fat for fuel, and will experience fatigue and what many describe as "hitting the wall". The diagram below illustrates how our bodies use more and more fat for fuel the longer we exercise.
What Should You Eat After Exercise?
Whether you’ve finished a long run or lifted weights, your number one priority after exercise should be replacing fluids. Drink fluids of some kind – water, sports drink, coconut water, etc. What you choose to drink is largely dependent upon what activity you did and for what duration. Typically, sports drinks should be reserved for exercise lasting more than 60 minutes, or when exercising in extreme heat. Read more about coconut water, and when it’s best to consume, here. Aim for 20-28 ounces of fluid for every hour of exercise to ensure proper hydration.
Second priority is replenishing your glycogen stores with a carbohydrate source, ideally 15-45 minutes after your workout. Research has found that if a high-carbohydrate meal is eaten within 15 minutes after exercise, the rate of glycogen storage accelerates by 300%. If you wait longer than two hours after your workout to refuel, your glycogen storage capacity declines by half, and your protein repair by 80 percent! By eating soon after exercise, you are not only replacing lost glycogen, but increasing your glycogen capacity so you have more energy (and therefore, endurance) the next time you exercise. So, make it a priority to refuel no more than two hours after your workout. The sooner you can do it, the better! Aim for 30 – 60 grams of carbohydrates for every hour of exercise.
To further improve your glycogen storing capability, eat a carbohydrate and protein source together. Research has found that when protein is added to carbohydrates, blood insulin levels increase. Blood insulin stimulates glucose uptake in the muscle (which converts to glycogen) and increases the rate of protein synthesis. The optimal ratio is 4:1 (four grams of carbohydrates for every gram of protein). Research has found that those who refuel with this ratio of carbs to protein have twice the glycogen stores as those who only eat carbohydrates.
When you exercise, your muscles become very sensitive to certain hormones and nutrients. This is the perfect opportunity for athletes to provide the right nutrients to improve performance. The increased sensitivity only lasts for a limited amount of time, so it’s very important to use this window of opportunity.
Here are some examples of good post-workout snacks:
- cereal with milk
- fruit with greek yogurt
- toast/bagel/english muffin with peanut butter or cheese
- cottage cheese with fruit
- chocolate milk (scientifically proven to be one of the best post-exercise recovery aids!)
- smoothie made with a protein source (milk, yogurt or protein powder)
- piece of bread with sliced turkey
If you have any questions, please feel free to email me at thesaltedkitchen@gmail.com!
34 Comments
What an informative post! I never know what to eat or when to eat it in regards to exercising. I do manage to drink a glass of chocolate milk after my runs.
What would be the best source for someone who can’t drink pasteurized milk? And thank you for the info, I need to work on having a good pot-workout snack!
@Katie @ Peace Love and Oats: Do they make unpasteurized chocolate milk? Otherwise I know there are chocolate soy, almond and hemp milks out on the market. Otherwise, there are plenty of other foods, like those listed above.
If you work out first thing in the morning, should you eat a meal or a snack?
@Alyssa (pb and oatmeal): Yes, because you’re coming off an overnight fast, your body needs glucose in the blood to provide immediate energy. Eat a banana, peanut butter toast, or glass of milk before heading out for your workout.
I am so excited to see chocolate milk part of the list!
Great guest post! Chocolate is by far my favorite post-run fuel. I always recovered best when I had it after long runs during half-marathon training.
Thanks for explaining this in a simple, yet detailed way! These are things I’ve always heard, but never knew the science behind.
This is a very informative post. You definitely made a lot of sense with the “geek” parts, but now I have a question! lol. Many people exercise to lose weight, but how does burning glucose accomplish that? I thought that you -wanted- to burn fat? I realize that 2000 calories (like in the example above) needs to be replenished, but I guess I am still a little confused š
@peanutbutterlover: Good question! I wrote this post with athletes who are trying to maintain their weight in mind – not those trying to loose weight. But I knew the question would come up.
The body has a very hard time turning fat into energy, it takes a lot more work. Carbohydrates (glucose) are much easier, and more efficient way for the body to get energy. If your trying to bike 100 miles, run a half marathon or do some other sort of long-duration exercise, you want your body getting energy in the easiest way possible.
Now if your trying to loose weight, yes, you want to burn fat. The most effective way to do that is anaerobic activity (think sprints, lifting weights, burpees, etc). Your goal should be 60-70% max heart rate for optimal fat burning (220-age is your max, take 60-70% of that for the range).
I hope that’s helpful. If you have more question, email me at thesaltedkitchen@gmail.com!
@Nicole: @Nicole: Thanks. That is helpful!
I will need to look at that chocolate milk link. I’m a very intuitive eater because I feel my body knows best. And after a workout session, it craves chocolate milk. And I was never much of a chocolate person before this.
Great post, thank you!
What a great post- thanks for all the info! I need to be reminded of this!
This is one of the most helpful posts I’ve read, thank you!
Awesome post. Thanks for the insightful information.
This was a great read, thanks. I’m curious how early before a workout should you eat your pre-fuel snack? Sometimes it seems I eat way too early and it does me no good and others I feel like it’s still sloshing around in my stomach. I’m sure it depends too on what it is.
Great post! I learned a lot of this stuff in my sports nutrition class this year (I’m in school to become an RD) and it’s nice to see an online source with accurate information. It’s crazy how many websites are out there with completely false info about nutrition!
excellent post!! this is perfect timing as i have an exam on this thursday… nutrition graduate right here in T-5 days!!!
I’m sort of a science and sports nutrition nerd so I LOVE reading about food for fueling workouts, etc! Great post!
Great info! Now that I’m running longer distances on a consistent weekly basis, pre and post workout foods are top of mind!
EXCELLENT! A new blog to follow!
Mmmm i love any excuse for cereal with milk š
Great post! I’m always interested in this sort of stuff but a lot of articles are hard to follow. Thanks for sharing š
AWESOME post! Wow! so helpful, insightful and made sense!!! Thank you!
Loved this!! My boyfriend swears by chocolate milk as a recovery drink so he’ll be happy to see it made the list! š
thanks for the tips! I learned about this in my Intro to Nutrition class, but not quite as in depth as to “why” so I appreciate the science behind it. I’m pretty bad about refueling after intense exercising so I’ll be sure to keep this in mind. thanks!
Great post. Are egg whites/eggs a good choice for fuel post workout?
@Susan: Eggs or egg whites are great protein sources, but you’re not getting any glucose. Try having a glass of milk with it, or eat the egg over toast for a carbohydrate source.
Nice post, but studies don’t “prove” they provide evidence. Re: chocolate milk.
Hello! I’m currently an exercise science student and took my first sports nutrition class this past semester…so interesting! I love that you provided this information here, this subject is so important for athletes and is very under-discussed.
Kelsy š
Great post!
Do you have any suggestions for non dairy post exercise fuel? Any suggestions for a ‘cleaner’ chocolate milk with less sugar?
@Luv What You Do: Sorry I missed this comment! I know there are dairy alternative chocolate milks – chocolate almond milk, or chocolate soy milk. I’m not familiar with what the label or nutritional profile is like on these products, however. Other non-dairy post exercise options are peanut/almond butter stuffed dates, banana with peanut butter, half a turkey sandwhich, or dried fruit and nut trail mix.