Whether you are an avid gym goer or just starting out, you most likely have put in a lot of thought into your pre-exercise nutrition to ensure you have the energy to perform at your best. But, have you put enough effort into your post exercise nutrition? Consuming the right nutrients following your exercise is just as if not more important than your pre-exercise nutrition!
To really understand the importance of post-exercise nutrition we first need to grasp what occurs to your body during exercise. While we are physically active our body will deplete our energy stores within our muscles (ie. glycogen) in addition to breaking down/damaging proteins in your muscles. Following completion of the physical activity your body will start to replenish the depleted energy stores and repair the damaged muscles. If you consume the correct nutrients within the correct time frame following a workout you will be able to enhance this process by decrease muscle protein breakdown, increase muscle protein synthesis (ie. repair and growth of the muscle), restore energy stores (ie. glycogen stores in the muscle) and increases overall body recovery.
Now you might be asking what nutrients are the most important nutrients to consume following a workout and how much of each should you consume of each?
Protein - As I mentioned above, physical activity triggers a catabolic (breakdown) state for your muscles. Each muscle contraction during exercise causes microscopic muscle tears (ie. damaged muscles and proteins) that your body will later repair. Consuming appropriate quantities of protein following a workout is essential to give your body the building blocks (ie. amino acids) not only to repair the muscle damage caused through physical activity but also create new tissue to increase muscle mass. Most individuals will need about 0.3-0.5 grams of protein per kilogram of body weight. Different types of activity will cause different proportions of muscle damage needing to be repaired. For example, resistance training (ie. weight lifting) will cause more and larger microscopic muscle tears than endurance training (ie. jogging) and therefore would require you to consume slightly more protein to provide the building blocks to repair the muscle from this type of workout.
Carbs - Exercise depletes our energy stores (glycogen) in the working muscle. The rate and quantity of energy consumed during exercise is proportional to the type of exercise you are involved in. For example, endurance exercise such as running, swimming, biking, ect… will deplete your energy stores to a greater extent than a low intensity resistance training session. Regardless of the rate and quantity of energy consumed during exercise, following completion of the physical activity your body will start to replenish these energy stores. Consuming 1.1-1.5 grams of carbohydrates per kilogram of body weight following a training session stimulates adequate glycogen resynthesis. Furthermore, studies have shown that consuming protein at the same time as carbohydrates increases insulin secretion which promotes glycogen synthesis. Therefore consuming both carbohydrates and protein together following a workout maximizes both protein and glycogen synthesis to improve recovery.
Fats - Although fats may not provide a large advantage in your post workout nutrition they also do not hinder the effectiveness of your post workout nutrition when consumed in appropriate quantities. For example, studies have shown that consuming whole milk was more effective to promote muscle growth than skim milk following exercise. Although we need to be mindful of the type of fats we are consuming to ensure we limit the quantities of saturated and trans fats, consuming healthy fats following a workout will not hinder your recovery.
The last piece of the puzzle to put together is the timing of your post workout nutrition. The sooner you can start consuming these nutrients the better. Following physical activity your body's ability to rebuild glycogen stores is enhanced and is the perfect time to consume adequate protein and carbohydrates to stimulate this process. There are a lot of theories for exact timing of consumption of nutrients however many experts recommend an ideal window of 15-45minutes post workout to maximize the effectiveness. Studies have shown delaying carbohydrate consumption to more than 2 hours post workout has decreased glycogen synthesis by as much as 50%! One thing to keep in mind is the timing of your pre-exercise nutrition as well. If you had consumed a meal shortly before your physical activity you most likely will be receiving the benefits from the nutrients following the exercise as your body would not be able to digest and absorb all of the nutrients prior to starting exercise.
What are the take home messages to put this all together?
During exercise our bodies deplete our energy stores and breakdown muscle proteins
The type of exercises will dictate how much muscle breakdown and glycogen depletion will occur - endurance exercise greater glycogen depletion, resistance training greater muscle/protein breakdown
Consuming protein following exercise will help to decrease muscle breakdown and increase protein synthesis to repair damaged muscle and create new tissue
Consuming carbohydrates following physical activity will help to replenish glycogen stores
Consuming both protein and carbohydrates together maximizes both protein and glycogen synthesis following exercise
Fats do not hinder post workout nutrition however be mindful of the types of fat consumed (ie. mono- and poly-unsaturated fats)
You need to drink an adequate amount of water to replenish lost water and electrolytes due to sweat and internal chemical reactions. If the physical activity is a high enough intensity lasting for over 45 minutes you may need to intake an electrolyte drink to help increase water and electrolyte absorption.
Timing of nutrient consumption is crucial to promote recovery. Try to consume nutrients within the first 15-45 minutes following a workout.
- KENT UTMAN