Nutrition requirements after exercise will depend on the type of workout performed, for example resistance training or cardiovascular training, the intensity of the workout, and the overall goals of the individual. Post-workout nutrition aims to promote optimum recovery between workouts and to maximise results. The three key principles of recovery nutrition are to:
- Refuel the muscle and liver glycogen (carbohydrate) stores;
- Rehydrate by replacing the fluid and electrolytes lost in sweat; and
- Repair muscle tissue and promote muscle adaptation.
Refuelling after Workouts
After moderate- and high-intensity exercise your muscle glycogen (carbohydrate stores) will be depleted. If these glycogen stores are not replaced, your performance during your next workout will be compromised. The main dietary factor in post-workout refuelling is the amount of carbohydrate consumed. The amount you require will depend on the fuel cost of the workout you completed and the timing of your next session. If an intense workout is planned within the next 24 hours, consuming carbohydrate within the first hour of finishing is ideal for replacing glycogen stores. The meal or snack should provide 1-1.2 grams of carbohydrate per kilogram of body weight. If your goal is weight loss, you can still aim to refuel glycogen stores before your next session, however, it is important that the post-workout meal is considered as part of your overall energy (kilojoules) budget. You may wish to plan for one of your main meals or snacks to be consumed straight after your workout. This meal should provide a nutritious carbohydrate source along with other nutrients such as protein, vitamins, and minerals.
Rehydrating after Workouts
After training, replacing water plus electrolyte losses is important for optimal recovery. You continue to lose fluid through sweat and urine even after finishing your session, so (as a general rule) you should aim to replace losses by 150%. In practice, this means if you are 1 kilogram lighter after your workout, you need to drink 1.5 litres over the next 2-6 hours. Remember 1 kilogram weight loss equals 1 litre of fluid deficit.
If sweat rates were high, include a source of sodium to replace lost electrolytes and help the body to re-hydrate more effectively. Sports drinks, milk, soup, and pretzels are all examples of sodium sources that can help with re-hydration after workouts. Remember that these also provide additional energy (kilojoules) and should be considered in your total energy budget.
Muscle Repair after Workouts
High-intensity or strength-based workouts result in the breakdown of muscle tissue. Taking in protein after a workout provides the amino acid building blocks needed to repair muscle fibres that get damaged during exercise and to provide the development of new muscle tissue. Although protein requirements vary between individuals, consuming 15-25 grams of protein within an hour after exercise can help maximise the muscle rebuilding and repair process. Consuming protein after this ‘window of opportunity’ will still promote the muscle rebuilding and repair process, though the rate at which it occurs is less. Adding a source of carbohydrate to this post-workout meal or snack will further enhance recovery by reducing the degree of muscle protein breakdown. Carbohydrate intake helps stimulate the muscle to take up the amino acids. A protein-carbohydrate meal or snack after a workout is useful not only for muscle repair and adaptation to training but to meet the goals of refuelling muscle glycogen stores.
Does Protein Type Count?
Although research is continuing to evolve, it seems the type of protein you consume can also impact on your results, particularly when it comes to building muscle. Animal-based proteins such as diary, meat, poultry, fish, and eggs are considered to be of high quality due to the protein in the food containing all the essential amino acids required to build muscle tissue.
There are also different classes of proteins in these foods. For example, milk is made up of two key proteins – casein and whey. Both are high quality proteins, but whey is known as a ‘fast protein’ because it is quickly broken down into amino acids and absorbed into the bloodstream, making it ideal to include after your workout. Casein, on the other hand, is digested more slowly. While these ‘slow proteins’ do not promote muscle formation, they do prevent muscle breakdown. Casein is also ideal for providing your body with a steady supply of smaller amounts of protein for a longer period of time. Since milk contains both, one big glass gives your body an ideal combination of muscle-building and muscle-protecting proteins.
Plant foods such as bread, pasta, rice, breakfast cereal, legumes, lentils, and nuts also contain protein, but these sources are incomplete and are missing some important amino acids. It is important to mix these incomplete proteins together to ensure adequate amino acid balance.
The above content is intended for informational and educational purposes only, and in no way is any of the content to be construed as medical or dietary advice or instruction. For personalised medical or diet advice, please consult with your medical/health or dietary/nutritional professional.