What you eat and when you eat can have a big impact on both fat loss and muscle building. This is referred to as nutrient timing which means consuming specific food types at a time when your body has the best ability to utilize the nutrients. The science behind nutrient timing suggests that this is key to successfully achieving these health, fitness and performance goals. This article will review the current understanding of how nutrient timing helps to replenish muscle glycogen stores, restore physiological function, repair tissue damage and promote muscle growth. Maximise Your Workout with Nutrient Timing…
There are three distinct phases in the nutrient timing system that are based on muscle, its nutritional requirements, and its recovery demands. However, it is important to first understand the basic hormones involved in this process.
The Hormonal Responses To Exercise
The science behind this way of eating really revolves around our hormones. Hormones are responsible for bone growth, fat loss and muscle growth. Within the body are numerous catabolic (breaking down) and anabolic (building up) hormones that are stimulated by exercise. Catabolic hormones are responsible for the disassembly of nutrients for energy production or cell needs. The main catabolic hormones of exercise are epinephrine, norepinephrine, cortisol and glucagon. Anabolic hormones support muscle hypertrophy (growth), tissue repair, inflammation control, and regulate our metabolism.
When it comes to nutrient timing, insulin is the key hormone. Insulin is able to increase the storage of fat cells, and it can do the same for muscle. After we eat carbohydrates, insulin is released by the body and it is responsible for transporting amino acids, carbohydrates and fat into the cells in our bodies.
To put this into real terms, after completing a weight training session for example, the muscles are like an empty gas tank that desperately needs to be refilled. To replenish this critical energy supply, we consume carbohydrates. Therefore, to avoid fat storage, the best time to consume carbohydrates is after working out because our muscles will use the nutrients to repair themselves instead of the body storing them as fat.
What are the three nutrient timing phases?
The nutrient timing system is split into three distinct phases:
1) Energy Phase (just before and during workout)
2) Anabolic Phase (post 45 minutes of workout)
3) Growth Phase (remainder of the day)
- The Energy Phase
Muscle glycogen is the primary fuel (followed by fat) used by the body during exercise. Low muscle glycogen stores result in muscle fatigue and the body’s inability to complete high intensity exercise. The depletion of muscle glycogen is also a major contributing factor in muscle weakness. So, the need for carbohydrates is high for all types of exercise during this energy phase.
The goals with the energy phase are to increase nutrient (primarily carbohydrate and some protein) delivery to muscles, spare glycogen and protein loss, minimize muscle damage, limit immune system suppression and prepare nutritionally for a faster recovery.
According to scientists, prior to aerobic exercise, protein intake with carbohydrate supplementation has been shown to stimulate protein synthesis post-exercise. Additionally, carbohydrate supplementation before resistance training helps maintain blood glucose levels and therefore can increase the body’s capacity to perform more sets, repetitions and prolong a resistance training workout.
- The Anabolic Phase: The 45 Minute Optimal Window
The anabolic phase is a critical phase occurring within 45 minutes post-exercise. During this time muscle cells are particularly sensitive to insulin, making it necessary to ingest the proper nutrients in order to make gains in muscle strength. Ingesting the same nutrients 2 – 4 hours post-exercise will not have the same effect. Moreover, during this time the anabolic hormones begin working to repair the muscle and decrease its inflammation caused during training.
A carbohydrate snack consumed within 45 minutes post-exercise has numerous benefits as the muscle cells can pick up glucose quickly during this period. This aids the recovery process, and can increase protein synthesis which is key for muscle gain.
- The Growth Phase
The growth phase consists of the 18 – 20 hours post-exercise when muscle repair and growth and strength increases occur. The goals of this phase are to continue to replenish glycogen stores and to maintain the anabolic state. Consuming a protein and carbohydrate meal within 1 – 3 hours after resistance training has a positive stimulating effect on protein synthesis.
Recommendations for the fit minded and committed!
During the energy phase a drink consisting of high-glycemic carbohydrate and protein should be consumed. This drink should contain a 4:1 ratio of carbohydrate to protein and should include approximately 6 grams of protein and 24 grams of carbohydrate. Additional drink composition substances should include leucine (for protein synthesis), Vitamin C and E (because they reduce muscle damage), and sodium, potassium and magnesium (which are important electrolytes lost in sweat).
During the anabolic phase a supplement made up of high-glycemic carbohydrate and protein should be consumed. This should be a 3:1 ratio of carbohydrate to protein and should contain approximately 15 g of protein and 45 g of carbohydrate. Other important drink substances include leucine (for protein synthesis), glutamine (for immune system function), and antioxidant Vitamins C and E.
During the rapid growth phase a drink filled with high-glycemic carbohydrates and protein may be consumed. In this phase the ratio of carbohydrates to protein should be 1:5 with 4 g of carbohydrate to 20 g of protein.
All these values are of course simply indicative, based on a 60-65kg male individual. Each person would have specific nutrient need depending on many factors such as age, gender, physical condition, training routine etc.
Now, lets simplify all the above. Most people are unsure about what kind of snacks to go for and the wrong choices may compromise all the hard work at the gym. Forget about the numerous supplements available in stores; in fact only a few of them are actually scientifically proven to work! Here are a few examples of quick and easy pre and post exercise snacks that will do the job just fine if not better!
Easy Pre-Exercise Snack Ideas
- Fruit salad with yoghurt
- Cereal bar
- Fruit smoothie or milk shake
- Breakfast cereal with milk
- Crumpets with jam/honey and milk
- Fruit-flavoured yoghurt
Easy Post-exercise Snack Ideas
- Milk shake or fruit smoothie
- Fruit salad with fruit yoghurt
- Breakfast cereal with milk
- Crumpets with peanut butter and milk
- Flavoured milk and cereal bar or banana
- Fruit yoghurt and cereal bar or banana
- Fruit yoghurt and flavoured milk
Building Muscle? The Secret To Maximising The Effect of Protein
Prolonged and high-intensity exercise causes muscle breakdown, so repairing this damage is important. Protein in your post-exercise snack will provide the amino-acids the body needs to start repairing any damage to the muscles from the exercise session and encourage the muscle rebuilding process. According to the International Society for Sports Nutrition, in order to maximise the effect of protein it should be consumed with carbohydrate. This has been proven to have better results than simply consuming protein supplements. So, you can maximise your results simply by ensuring any food you eat after training contains both carbs and protein.
In the areas of nutrition and exercise physiology, nutrient timing has attracted scientific interest. Among the many benefits of ingesting the appropriate amounts of carbohydrate and protein at the right times are enhanced glycogen synthesis, replenishment of glycogen stores, decreased muscle inflammation, increased protein synthesis and muscle development, faster muscle recovery and higher energy levels. Nutrient timing is therefore an important strategy, but it’s not for everyone. If you’re new to healthy eating, start by improving the overall quality of your diet and adopt a healthy balanced lifestyle. Once you build a foundation of nutritious eating and regular exercise, then consider adding the nutrient timing habit. It is very important to have realistic goals when hitting the gym, avoid overtraining and remember moderation is the key!