There is a lot of conflicting information out there surrounding nutrition and exercise. People like to throw around phrases like "pre-workout" and "optimal window" and "fed vs fasted workout" and "nutrient timing". The truth is, what is important regarding exercise nutrition really comes down to what your individual goals and preferences are. Over the next few posts, I will breakdown the reasons for nutrient consumption before, during, and after working out, and whether it would fit into your personal fitness goals. And, although it may seem a little backward, the first post will focus on post-workout nutrition, which is often looked at as one of the most important pieces of recovery.
WHY IS POST-WORKOUT NUTRITION IMPORTANT?
During exercise, muscles are broken down and energy is expended. Exercise is a stressor to the body, and it needs the proper tools to help repair it and hopefully make it stronger in the process. Immediately after working out, muscle breakdown increases significantly, surpassing the rate of protein synthesis. This results in a breakdown of muscle. At the same time, the energy store in your muscles is decreased. In order to help your body repair itself, you should consume a mixture of protein and carbohydrates.
Protein is important in the post-workout period for two reasons: it stimulates protein synthesis in the muscles, and if consumed directly after your workout protein stimulates more protein synthesis than when consumed at rest. What does that mean? It means that when your post-workout meal includes protein, your body will begin building protein back up, and at a greater rate than it would had you consumed the same amount of protein at rest.
Carbohydrates are also important post-workout for two reasons: they increase insulin levels which suppresses muscle breakdown rates, and they refill the muscles with glycogen which was used as fuel during the workout.
WHEN SHOULD POST-WORKOUT BE CONSUMED?
Ideally within an hour of finishing your workout. The reason for this is that after exercise, there is increase blood flow to the muscles, which allows for the nutrients in the blood supply to enter them more quickly. The muscles are considered "primed" for nutrition at this point which is often referred to as the "window of opportunity". After exercise, this window begins to close as blood flow slowly reverts back to resting rate. In order to reap the benefits of increased protein synthesis and glycogen storage, a combination of protein and carbohydrates should be consumed in this window.
WHO NEEDS POST-WORKOUT NUTRITION?
This is where things get a little tricky, and it depends largely upon the intensity of your workout and what your fitness goals are. Post-workout meals become important after high intensity exercise. High intensity can consist of: circuit training with challenging weights, a HIIT workout, or a speed workout/long run. If your workout consists of a few rounds of push ups and sit ups or if you go for an easy 3 mile run, a meal directly after your workout will not be necessary, since your muscles are not being broken down in the same accelerated way that they are in a higher intensity or more challenging workout.
Your goals are also a factor here. If your goal is weight loss, what you consume post-workout will look very different from someone who is trying to build muscle. In both cases, post-workout nutrition is important for the body to function at its best. With the goal of fat loss, however, there will be less emphasis on carbohydrates after your workout. Remember carbs assist in suppressing muscle breakdown and refilling glycogen stores. While this is important, it may not be necessary if your main goal is fat loss. The reason for this is that research shows that only a moderate amount of insulin is necessary to assist in suppressing muscle breakdown, which could be achieved by protein consumption alone. And, while refilling glycogen stores is important, carbs ingested later in the day will do the same job, although it will occur at a slower rate. Unless you plan to workout later in the day, this slower refill rate should not affect your performance. Carbs exceeding what is used for energy storage in muscles will be stored as fat. So, when aiming for fat loss, it is best to keep your post-workout consumption lower in carbs.
Another thing to keep in mind when the goal is fat loss is the "calories in vs calories out" rule. While weight loss is more complex than that, it is important to remember that when you are trying to lose weight, adding meals or snacks after a workout still count as "calories in". Your ultimate goal is to have an energy deficit by burning more than you are consuming. Adding a calorie dense snack after exercise can potentially derail all of the hard work you are putting in if you do not factor it into your daily meal plan as a whole. If you plan to have a substantial meal within 1-2 hours after exercise then you may consider skipping a post-run snack.
Now, if your goal is to increase muscle, then consuming a mix of protein and carbs after exercise becomes much more important. The only way for muscles to grow is to synthesize proteins faster than they are being broken down. Protein, of course, would be necessary here, but carbs also become more important. Higher carb meals tend to result in higher insulin levels, which maximizes protein synthesis.
WHAT SHOULD YOU CONSUME POST-WORKOUT?
As we've already covered, a mixture of protein and carbs is key after exercise. But in what form should they be consumed? Liquid forms of nutrition tend to be preferable over whole food directly after exercise because many people find whole foods unpalatable after working out and whole foods are digested more slowly than liquids. That being said, easily digested whole foods can be consumed and still result in the same benefits. Examples for post-workout nutrtion:
- Protein shake (with or without fruit depending on goals)
- Omelette with veggies and toast
- Yogurt with fruit
- Egg white wrap
- Pita and hummus
- Cottage cheese and fruit
The most important thing is to find what works for you body and stick with it. In the next post, I will focus on pre-workout nutrition. Any questions? Feel free to ask below!