In today's society of being faster, fitter, stronger and leaner, an athlete or any physically active individual can be challenged to find safe and effective ways to achieve those body goals. There are many real and perceived benefits of achieving and maintaining a leaner body with lower amounts of body fat.
The long-term health benefits include decreased risk of cardiovascular disease, reduced amounts of the bad cholesterols and increased amounts of the good cholesterols that protect the heart, reduced blood pressure and better maintenance of blood-sugar levels.
In females, lower body fat may also protect against breast and some other reproductive cancers. Lower body weight and body composition also are believed to positively influence physical performance and the aesthetics of performance.
Athletes involved with weight classification sports (e.g. youth football, wrestling, rowing or boxing) are very familiar with the impact of weight and body composition on physical performance, and their governing bodies have recommendations on how those body weights may be achieved.
However, there are many more athletes and physically active individuals who do not have these types of guidelines to follow. Dancers, distance runners, gymnasts and clyclists often believe that weight and body composition will influence their physical performances and the aesthetics of those performances; however, their governing organizations have no mandated weight control practices.
In addition to athletes, physically active individuals and others involved in recreational activities also may be interested in maintaining healthy body weight and fit appearance, but they often are unable to access accurate information or assistance to do so.
Methods Often Inaccurate
Healthy body weight and body composition goals should be determined using the most scientifically accurate method available. Unfortunately, not all individuals who seek a healthy body weight or lean/fit appearance attempt to achieve those goals in a healthy and safe manner.
Many individuals determine their "goal weights" by referring to standardized height and weight charts or using the BMI (body mass index) methods, but these methods are not accurate for individuals who are muscular.
Armed with this misinformation, these individuals often attempt to lose weight by not eating, engaging in unhealthy weight control behaviors and/or restricting fluids. The use of unsafe weight management practices can compromise physical performance, negatively affect health, and even lead to a poor body image as a result of misinformation or influences from coaches, parents, or peers.
At its 62nd Annual Meeting & Clinical Symposia, the National Athletic Trainers' Association (NATA) released a position statement on "Safe Weight Loss and Maintenance Practices in Sport and Exercise." It was published in the June 2011 issue of the Journal of Athletic Training, the NATA's scientific publication.
The purpose of the position statement is to present athletic trainers and other health care providers with recommendations for safe weight loss and weight maintenance practices for athletes and the physically active, plus guidelines for coaches and parents that will allow athletes and active individuals to safely achieve and maintain weight and body composition goals.
NATA recommends that both diet and exercise be used as part of the strategy to change body weight and body fat. Weight management (change) programs should coincide with the individual's training plans, as well as the performance and body weight goals of the individual. An individual's metabolism, energy needs, and exercise goals must be taken into consideration when choosing a diet or exercise protocol.
Diets should contain a sufficient amount of calories to meet not only the basal metabolic needs of the individual, but also the physical activity needs. This amount can be determined by using simple caloric estimation formulas like the Harris-Benedict or Mifflin-St. Jeor formulas, which take into account height, weight, age, and gender. Goal weights, rather than current weights, should be used in these formulas.
Diets also should include all food groups to ensure that all essential nutrients, including water, are represented and in sufficient amounts. Dietary intake of the energy producing nutrient should include carbohydrates (5-7 g/kg of body weight), proteins (.8-2.0 g/kg of body weight) and fats (~30 percent of total calories) to maintain adequate health and to absorb vitamins and minerals properly.
To ensure adequate hydration, an average adult's water intake should be 3.7 L/d for men and 2.7 L/d for women. Athletes, other physically active individuals, and those who are exposed to hot environments need higher intakes of total water. To maintain adequate hydration, an active individual should drink 200 to 300 mL of fluid every 10 to 20 minutes during exercise.
Diets that restrict certain nutrients and/or over-emphasize others can lead to physiological imbalances within the body and prevent the individual from achieving his or her goal. Very low-calorie diets can cause heart dysrhythmias, changes in heart rate and blood pressure responses to exercise, and sudden cardiac death.
Restrictive diets can affect the endocrine system and that system's ability to regulate growth, bone mineralization (potentially leading to the development of osteoporosis), and stress fractures.
Dietary restrictions also can affect the immune system by significantly impairing normal function and may lead to an increased number of infections during the period of inadequate dietary intake. Excessive intakes of one nutrient also can result in imbalances within the body and again prevent the individual from reaching his/her body composition or performance goals.
All weight management programs should include both a diet and exercise plan. Exercise programs should require a minimum of 30 minutes of exercise, 5 days per week, to maintain good health; however, to facilitate weight and body fat loss, it will be important for the individual to participate in continuous, rhythmic aerobic exercise longer than 30 minutes per exercise bout, but no longer than 60 to 90 minutes, for at least 150 minutes per week.
Maintaining a heart rate at approximately 55 to 69 percent of the individual's predicted maximum heart rate (220 minus age) will facilitate the body fat loss. Caution is advised for those with orthopedic or other health conditions that may warrant changes in exercise protocols.
Non-weight-bearing or limited-weight-bearing aerobic exercises are recommended for those with orthopedic conditions.
Combining weight management and body composition goals with physical conditioning periodization goals can assist athletes and others in reaching their weight goals.
Periodization involves manipulating training intensity and volume to yield specific performance outcomes. The best time for adjustments in weight and body composition is during the preparatory period or months preceding a competition.
The main emphasis of the competitive period should be on performing the sport or activity with the body nearing its highest level of physical fitness. During the competitive period, less time is available for physical conditioning and more time is spent on strength, power, and increased training intensity specifically related to sport performance.
During the different phases of the preparatory period, physical conditioning goals can be used to achieve body composition goals. During the hypertrophy or endurance phase, the emphasis is on developing lean body mass, aerobic capacity, and muscular endurance, which can provide a physiologic environment to assist in decreasing body fat.
During the basic strength and strength or power phases, the emphasis is on developing strength and speed and involves increasing levels of anaerobic activity. An athletic trainer or other trained health care professional should be consulted for assistance in manipulating these phases of the periodization plan to meet training goals.
Any changes in body weight or composition should be gradual, with no excessive restrictions or unsafe behaviors or products. On average, weight loss goals should be approximately 1 to 2 lbs. (0.5 to 0.9 kg) per week, but should not exceed 1.5 percent of body weight loss per week.
A higher rate of weight loss indicates dehydration or other restrictive or unsafe behaviors that will negatively affect performance and health. Progress toward reaching the target weight based on body composition tests should be assessed at regular intervals by repeating the body composition tests.
Dehydration will negatively impact physical performance. In adults, 2 to 3 percent dehydration causes decreased reflex activity, maximum oxygen consumption, physical work capacity, muscle strength and muscle endurance, and impairs temperature regulation.
At 4 percent to 6 percent dehydration, further deterioration occurs in maximum oxygen consumption, physical work capacity, muscle strength, and endurance time; temperature regulation is severely impaired and could result in increased risk of severe heat-related illnesses and even death.
Impact of Education
Finally, it's recommended that education on safe dietary and weight management practices should be conducted on a regular and planned basis; and the involvement of trained nutrition, health and weight management experts such as athletic trainers or other health professionals is highly recommended.
Coaches, peers and family members should not provide information or participate in diet, body composition or weight management practices and should refrain from making comments on them.
Athletes should be cautious with the use of dietary supplements and ergogenic aids for weight management, or any techniques that lead to rapidly changing body weight through unsubstantiated methods of weight reduction. Consideration of the sport governing boards' rulings on such supplements must be given.
To view the NATA statement, visit www.nata.org/sites/default/files/JAT-46-3-16-turocy-322-336.pdf.
This article was produced in cooperation with the National Athletic Trainers' Association (NATA), the professional membership association for certified athletic trainers and those who support the athletic training profession. For more information visit www.nata.org
Paula Sammarone Turocy is professor and chair of the athletic training department at Duquesne University in Pittsburgh.