This is an excerpt from Nutrient Timing for Peak Performance by Heidi Skolnik & Andrea Chernus.
What Are the Benefits of Nutrient Timing?
There are several benefits of nutrient timing. These involve maximizing your body's response to exercise and use of nutrients. The Nutrient Timing Principles (NTP) help you do the following:
- Optimize fuel use so that you remain energized throughout your training
- Ensure that you repair and strengthen your muscles to the best of your genetic potential
- Ingest sufficient nutrients to keep you healthy and able to fight off infection, limiting the suppression of the immune system often experienced with intense training
- Recover from your training so that you are ready for your next practice, event, or training session with well-fueled muscles
When sports nutritionists talk about energy, we are referring to the potential energy food contains. Calories are potential energy to be used by muscles, tissues, and organs to fuel the task at hand. Much of the food we eat is not burned immediately for energy the minute it's consumed. Rather, our bodies digest, absorb, and prepare it so that it can give us the kind of energy we need, when we need it. We transform this potential energy differently for different tasks. How we convert potential energy into usable energy is based on what needs to get done and how well prepared our bodies are; how we fuel endurance work is different from how we fuel a short, intense run. It is helpful to understand that you must get the food off your plate and into the right places in your body at the right time.
Clients consistently ask us, “What can I eat to give me energy?” For you, “energy” may have different meanings, depending on what you're referring to and how you're feeling. If you're talking about vitality, liveliness, get-up-and-go, then a number of things effect this: amount of sleep, hydration, medical conditions, medications, attitude, type of foods eaten, conditioning and appropriate rest days, and timing of meals and snacks. Food will help a lack of energy only if the problem is food related. You may think that's obvious, but it's not to some. If you're tired because you haven't slept enough, for instance, eating isn't going to give you energy. However, if your lack of energy is because you've eaten too little, your foods don't have “staying power,” you go for too long without eating, or you don't time your meals and snacks ideally around practice or conditioning, then being strategic with food intake can help you feel more energetic. What, how much, and when you eat will affect your energy.
Nutrient timing combined with appropriate training maximizes the availability of the energy source you need to get the job done, helps ensure that you have fuel ready and available when you need it, and improves your energy-burning systems. You may believe that just eating when you are hungry is enough, and in some cases this may be true. But, many times, demands on time interfere with fueling or refueling, and it takes conscious thought and action to make it happen. Additionally, appetites are thrown off by training, so you may not be hungry right after practice, but by not eating, you are starving while sitting at your desk in class or at work. Many athletes just don't know when and what to eat to optimize their energy stores.
By creating and following your own Nutrition Blueprint and incorporating the NTP, your energy and hunger will be more manageable and consistent, whether you are training several times a week, daily, participating in two-a-days, or are in the midst of the competitive season.
During the minutes and hours after exercise, your muscles are recovering from the work you just performed. The energy used and damage that occurred during exercise needs to be restored and repaired so that you are able to function at a high level at your next workout. Some of this damage is actually necessary to signal repair and growth, and it is this repair and growth that results in gained strength. However, some of the damage is purely negative and needs to be minimized or it will eventually impair health and performance. Providing the right nutrients, in the right amounts, at the right time can minimize this damage and restore energy in time for the next training session or competition.
The enzymes and hormones that help move nutrients into your muscles are most active right after exercise. Providing the appropriate nutrients at this crucial time helps to start the repair process. However, this is only one of the crucial times to help repair. Because of limitations in digestion, some nutrients, such as protein, need to be taken over time rather than only right after training, so ingesting protein throughout the day at regular intervals is a much better strategy for the body than ingesting a lot at one meal. Additionally, stored carbohydrate energy (glycogen and glucose) and lost fluids may take time to replace.
By replacing fuel that was burned and providing nutrients to muscle tissue, you can ensure that your body will repair muscle fibers and restore your energy reserves. If you train hard on a daily basis or train more than once a day, good recovery nutrition is absolutely vital so that your muscles are well stocked with energy. Most people think of recovery as the time right after exercise, which is partially correct, but how much you take in at subsequent intervals over 24 hours will ultimately determine your body's readiness to train or compete again.
Muscle Breakdown and Muscle Building
Nutrient timing capitalizes on minimizing muscle tissue breakdown that occurs during and after training and maximizing the muscle repair and building process that occurs afterwards. Carbohydrate stored in muscles fuels weight training and protects against excessive tissue breakdown and soreness. Following training, during recovery, carbohydrate helps initiate hormonal changes that assist muscle building. Consuming protein and carbohydrate after training has been shown to help hypertrophy (adding size to your muscle). The proper amount and mix of nutrients taken at specific times enables your body to utilize them most efficiently—that's one of the Nutrient Timing Principles.
Nutrient timing can have a significant impact on immunity for athletes. Strenuous bouts of prolonged exercise have been shown to decrease immune function in athletes. Furthermore, it has been shown that exercising when muscles are depleted or low in carbohydrate stores (glycogen) diminishes the blood levels of many immune cells, allowing for invasion of viruses. In addition, exercising in a carbohydrate-depleted state causes a rise in stress hormones and other inflammatory molecules. The muscles, in need of fuel, also may compete with the immune system for amino acids. When carbohydrate is taken, particularly during longer-duration endurance training (two to three hours), the drop in immune cells is lessened, and the stress hormone and inflammatory markers are suppressed. Carbohydrate intake frees amino acids, allowing their use by the immune system. Carbohydrate intake during endurance training helps preserve immune function and prevent inflammation.
Certain vitamins and minerals also play a role in immunity: iron, zinc, and vitamins A, C, E, B6, and B12. However, excess intake of iron, zinc, and vitamins A, C, and E can have the opposite effect and in some cases impair the body's adaptation to training. An eating plan incorporating all of these nutrients in reasonable quantities, such as amounts found in food, can help athletes maintain immunity. The quality of the foods selected is very important and needs to be just as much of a priority as the focus on carbohydrate or protein, for example. For instance, eating a bagel for the carbohydrate but also including an orange for the vitamin C is important; drinking a protein shake can be helpful at the right time, but including some lean steak or shellfish for the iron and zinc is also essential.
Did you know that dehydration and low blood sugar can actually increase your risk of injury? Avoiding injury due to poor nutrition is absolutely within your control. Inadequate hydration results in fatigue and lack of concentration. Low blood sugar results in inadequate fueling to the brain and central nervous system. This leads to poor reaction time and slowness. Poor coordination as a result can lead to missteps, inattention, and injury.
Additionally, chronic energy drain (taking in fewer calories and nutrients than needed) will increase your risk of overuse injuries over time. Stress fractures are one example; poor tissue integrity can happen when athletes think solely about calories taken in but not the quality of the calories consumed. This is what is behind the phrase “overfed but undernourished.” Eating lots of nutrient-poor foods will not provide your body with the building blocks for healthy tissues and overall repair. Inadequate protein will also hinder the rebuilding of damaged muscles during training. If muscles are not completely repaired, they will not be as strong as they could be and will not function optimally. The damaged muscle fibers can lead to soft-tissue injuries. Both protein and carbohydrate along with certain nutrients are needed to help with this repair. For instance, gummy bears may provide carbohydrate, but they don't contain any vitamin E, which is helpful in repairing soft-tissue damage that occurs daily during training. Therefore, the goal is both an appropriate quantity and an appropriate quality in food selection.