Extract Adapted From:
‘NSCA’s Guide to Sport and Exercise Nutrition’ edited by Bill Campbell and National Strength & Conditioning Association
The field of sport nutrition is continuing to grow. There is no better evidence of this than the escalating rate of record-breaking athletic performance, or the expanding amount of scientific research into the effects of nutrition on health, fitness, and body composition. Whether you are an elite athlete, sport nutritionist or a first-time gym member, this article will help you improve your performance by applying the latest scientific findings in your program and cover the basics of building a balanced nutrition plan that results in high energy, good health, top performance.
Body Composition and Energy Expenditure
A desire to improve body composition may be due to a wish to improve athletic performance. Although, many athletes and fitness enthusiasts also seek to improve body composition for aesthetic reasons. Therefore, athletes often put more effort to improve or maintain their body composition. Body composition can be modified through diet, exercise, nutritional supplements.
For athletes, adjusting their energy balance equation is the easiest way to change their body composition. Energy balance equation states that energy intake (food consumption) equals energy expenditure during normal metabolic processes and activity or exercise.
Total energy expenditure (TEE) is the total number of calories expended throughout the day including basal metabolic rate, thermic effect of food, and physical activity. It can vary depending on a person’s body size, gender, body composition, genetics, and physical activity level.
If more food is consumed than calories are expended, a positive energy balance is created and weight gain is likely to happen. If fewer calories are consumed than needed for normal daily activities an energy deficit is created which result in weight loss.
Nutritional Needs Analysis
Before working with an athlete to develop an individual nutrition plan, the sport nutrition professional must assess athlete’s body composition, weight history, diet history, and current diet. Lab works, bone density scans are other tools that can benefit in developing a plan tailored for an athlete. Body composition measure is way more accurate than the scale.
Most of the carbohydrates are provided by dietary plant sources. Some dietary carbohydrate, however, is found in animal products as well.
Carbohydrates are used throughout the body for various functions. Energy derived from the breakdown of carbohydrates powers many biological processes such as fuelling tissues in the body. The role of carbohydrate in exercise can be observed through performance decline as carbohydrate stores deplete.
In the resting state, our liver, pancreas, and other organs help keep blood glucose levels within a range to match the carbohydrate energy needs of various body tissues. After a meal, the body stores as much carbohydrate in the form of glycogen as possible while stimulating carbohydrate fuel use to help return the blood glucose level to normal.
The fundamental unit of protein is the amino acid. These amino acids are available to be used by the body directly. It is called protein synthesis when amino acids are used to produce new proteins. Dietary protein provides the amino acids that serve as the raw material for this process.
When these processes occur at an equal rate, protein balance is reached. In order for physiological adaptations to occur (e.g., muscle hypertrophy), the rate of synthesis must exceed the rate of breakdown. During resistance training without protein feeding, protein synthesis and breakdown increase too.
Protein needs of the athlete might be higher than the daily recommended intake, which is set at 0.8 g per kg of body weight (0.36 g/lb). Some important considerations for determining athlete-specific protein intake include training, periodization phase, goals, food choices and preferences, and total caloric intake.
Fat is much more than fuel. There are a variety of complex fats. Fatty acids are the major component of fats used by the body for energy and tissue development. The dietary fats that we ingest are incorporated into cell membranes, affecting biochemical processes and the physical nature of the cell. The results can include anti-inflammatory, anti-depressive effects that are important for athletes.
So how much fat is recommended in an athlete’s diet? There are no firm standards for optimal intake. The acceptable distribution range for fat is 20% to 35% of energy intake. In general, athletes report an average fat intake of 35% of total calories. It is recommended for athletes to intake an equal balance of saturated, polyunsaturated, and monounsaturated fats. Saturated fats are found in animal fat such as beef, dark meat in poultry. Monounsaturated fats are found in vegetable oils, such as olive oil, canola oil, and peanut butter. Polyunsaturated fats are found in most vegetable oils, nuts, cheese to some extent, and fish. Athletes need to make sure that they are selecting a variety of foods to obtain the recommended balance between the types of fat.
Water is the most important nutrient for the human body. It composes approximately 60% of a person’s body weight and can fluctuate between 45% and 75%. The amount of water in a person’s body depends on factors such as age, gender, body composition, and overall body size. Water is stored in different locations in the body. Typically, blood is 90% water, skeletal muscle is 75% water, bone is 25% water, and body fat is 5% water.
Athletes must pay attention to fluid and electrolyte balance during aerobic endurance exercise because of the increased chance of becoming dehydrated, overheated, or experiencing altered electrolyte balance. Sport nutritionists must help athletes monitor their hydration and teach them how to do this for themselves to be aware of the signs of dehydration, overheating.
Vitamins and Minerals
Vitamins and minerals function as metabolic regulators, influencing several physiological processes important to exercise or sport performance. For example, many of the B-complex vitamins are involved in processing carbohydrate and fat for energy production. Several B vitamins are also essential to help form hemoglobin in red blood cells, which is a major determinant of oxygen delivery to the muscles. Additionally, vitamins C and E function as antioxidants, which are important for better immune function.
Timing of nutrients facilitates physiological adaptations to exercise and can promote optimal health and performance. Nutrient timing recommendations vary for athletes within a particular sport as well as between sports. Travel, competition, training changes throughout the year will also affect an athlete’s nutrient timing. The dynamic nature of timing makes it important for athletes and coaches to develop a foundation of knowledge regarding consumption of nutrients and fluids.
Athletes needs to intake an optimal amount of carbohydrate pre-exercise. Postexercise carbohydrate can be either solid or liquid but should not be high in fructose. Athletes may also benefit from adding protein to their postexercise meal. The addition of protein has been shown to result in greater glycogen resynthesis (and greater protein synthesis) compared with carbohydrate only.
Consultation and Development of Athlete Plans
Sport nutrition is a field that changes constantly. Therefore, sport nutritionist must take a complete look at an athlete’s lifestyle, medical history, weight history, goals, injury report, body composition, and training program before helping them develop a nutrition plan. Along with good knowledge of the latest research and its application, the sport nutritionist needs to build good relationship with each athlete, in order to let them know they can trust the sport nutritionist and open up.
Many clients may have a fear of opening up and talking about behaviour they are ashamed of (such as binge eating or drinking, overeating, or disordered eating). Athletes must trust and be comfortable with sport nutritionists to talk about how they feel, what they are eating, how much they are exercising, and what they think about their body.