I have been training in kickboxing (Muay Thai), for about two years. When I first started, I had no idea how important my eating habits were to my performance. Through trial and error, I learned that what I eat, how much, and when plays a huge role in my energy levels. I went through a period of time where I was trying to lose a few pounds, so I cut back my food intake significantly (big mistake). I was exhausted, cranky, and had a lot of trouble making it through my workout. I also learned that eating a big meal close to the start of class made me sluggish and want to puke, and not eating enough made me feel weak. Through a little research and my own experience, here is what I now know:
Kickboxing is a high-intensity sport that requires a lot of energy—and the main source of this energy during your workout is carbohydrates. Carbohydrates are stored in your muscles and liver as glycogen. Your body uses these glycogen stores as energy during your workout. It is very important to include quality carbohydrates in your diet, such as whole grains, fruits, vegetables, and legumes to keep this energy store full. If you exclude carbohydrates from your diet, you won’t burn fat instead while exercising, you will just run out of energy.
The total amount of food you are eating also plays a role in your energy levels and body composition. How much you need to eat depends on your fitness goals.
If you are trying to lose weight: In order to lose one pound, you need to consume 3500 calories less than you are burning. 500 calories less per day is equal to one pound of weight loss per week. It is generally not recommended to lose more than two pounds per week. I you are eating too little, your metabolism will slow down (your body thinks it is starving, will break down your muscles, and will store any excess calories as fat) and you will not have enough energy to keep up with your exercise routine.
If you want to maintain your weight: Likely, if you are exercising more than you used to, you will need to eat more. Not only are you burning energy during exercise, but also you are building more muscle, which leads to more calories burned while at rest. If you feel hungry, then eat, but make sure that it is healthy food (fruits, vegetables, grains and lean dairy and meats). It is common when you exercise often to think: “I work out. I can afford to eat a hamburger with fries and pie and ice cream for dessert!” This type of thinking may lead to unwanted weight gain.
If you are trying to gain weight: To gain one pound of muscle per week, you need to eat about 350-500 calories more than you are burning daily (this only works if you are working out, otherwise it will become fat). Once you gain the muscle, it takes an adequate amount of energy intake to maintain this increased weight. These calories should come from carbohydrates, protein, and some fat. Keep in mind, there is a limit to how much muscle one can gain, and this limit depends on your gender, genetics, and exercise routine.
Not only is what you eat during the day important, but when you eat it. Eating too much too close to the start of your workout can make for a very uncomfortable experience, and not eating enough can make it difficult to maintain energy throughout the class.
It may be helpful to follow these guidelines:
2-4 hours before your workout: Eat a regular meal that includes a carbohydrate and protein source. If your meal is closer to the 2 hour mark, be sure to keep it relatively low in fat and fibre, as these nutrients slow the digestion of food and may give you a stomach ache during your workout. Examples of appropriate meals: Pasta with meat sauce and a side of salad. Meat or Tofu stir-fry with vegetables and rice.
1 hour before your workout: If you don’t have time to eat 2 hours before, eat a light meal or snack 1hour before. Keep this meal low in fat and fibre, and high in carbohydrates.
Afterwards, you will need to replenish the glycogen stores lost during your workout. The two hours after you exercise is when this process is most efficient. This can be a snack that includes carbohydrate and some protein or a meal if you didn’t eat one before class. Examples of post-workout snacks: Toast (carbs) with peanut butter (protein) and a piece of fruit (carbs). Smoothie with yogurt (protein), banana (carbs) and berries (carbs).