Center for Human Nutrition

Medical Nutrition Syllabus

Guide to Healthy Diet and Lifestyle

Exercise Guidelines

Managing Obesity

Exercise Prescription

Medicine and Surgery Nutrition Assessment Checklist

Pediatric Nutrition Assessment Checklist

Adolescent Nutrition Assessment Checklist
AMERICAN COLLEGE OF SPORTS MEDICINE EXERCISE GUIDELINES

A comprehensive exercise prescription for an individual is based upon an objective evaluation of that individual's response to exercise, including observations of heart rate (HR), blood pressure (BP), ratings of perceived exertion (RPE) and a subjective response to exercise.

The fundamental objective of an exercise prescription is to create a significant change in personal health behavior to incorporate habitual physical activity. Therefore, the most appropriate exercise prescription for a particular person is the one that is most helpful in achieving this behavioral change.

ACSM emphasizes that, " The art of exercise prescription is the successful integration of exercise science with behavioral techniques that results in long-term program compliance and attainment of that individual's goals."

ACSM GENERAL GUIDELINES FOR AEROBIC CONDITIONIING

The essentials of a systematic, individualized exercise prescription are based on the following components: Mode, Intensity, Duration, Frequency and Progression.

MODE

The greatest improvement in *VO2max, occurs when exercise involves the use of large muscle groups over prolonged periods and is rhythmic and aerobic in nature.

*walking;*jogging
*hiking;*running
*machine-based stair climbing;*swimming
*cycling;*rowing
*cross-country skiing;*combined arm and leg ergometry
*dancing;*rope skipping
*endurance game activities
Clearly, there is a wide-range of steady-state exercises to accommodate all fitness and skill levels. For the obese patient, a rhythmic activity as simple as walking has been found to be both efficient and effective in increasing heart rate and initiating caloric expenditure.

  *Maximal oxygen uptake (VO2max) Is the traditionally accepted c6te@on measure of cardiorespiratory fitness.

INTENSITY

Intensity and duration of exercise determine the total caloric expenditure during a training session and are integrally related. ACSM recommends that the intensity of exercise be prescribed at 60 to 90% of maximum heart rate (HRmax). However, patients with a very low initial level of fitness respond to a low exercise intensity, for example 30 to 60% of HRmax. Several important factors to consider prior to determining the level of exercise intensity include: the patient's fitness level, presence of medications that may influence heart rate, risk of cardiovascular or orthopedic injury, a patient's preferences for exercise and specific program objectives.

FORMULA FOR ESTIMATING TARGET HEART RATE

Formula for estimating maximum heart rate (HRmax):

HRmax = 220 - Age

Formula for estimating target (training) heart rate:

HRm= X exercise intensity, i.e. 60%, 70%, 80% etc.

EXERCISE DURATION

ACSM recommends 20 to 60 minutes of continuous aerobic activity. Initial goals should be set reasonably so that patients can reach preset goals with exercise sessions of moderate duration (20 to 30 minutes). For severely deconditioned patients, multiple sessions of short duration (-10 minutes) may be necessary. Increases in exercise duration should be instituted as the patient adapts to training without evidence of undue fatigue or injury.

EXERCISE FREQUENCY

Frequency is interrelated with both intensity and duration of exercise and therefore depends on those two variables. Patients with a low level of fitness benefit from multiple short daily exercise sessions. For patients of moderate to higher levels of fitness, 3 to 5 sessions per week are recommended. The number of exercise sessions per week may vary and are based on caloric expenditure goals, patient preferences and limitations imposed by lifestyle.

ACSM recommends minimal thresholds of 300 kcal per exercise session performed 3 days per week or 200 kcal per session done 4 days per week. A reasonable approach in prescribed exercise programs is to target a weekly exercise caloric expenditure of approximately 1000 kcal. In order to achieve optimal physical activity levels, the goal is to bring the weekly expenditure closer to 2000 kcal as health and fitness permit.

PROGRESSION

The recommended rate of progression in an exercise conditioning program depends on functional capacity, medical and health status, age and a patient's activity preferences and goals. The endurance aspect of the exercise prescription has 3 stages.

The Initial Conditioning Stage- This stage last for about 4 or 5 weeks with an exercise intensity beginning at about 40% of HRmax progressing to 70% with sessions lasting from about 12 minutes up to a@6und 20 minutes with a frequency of 3 times a week.

The Improvement Stage- This stage typically lasts from 4 to 5 months, during which intensity Progressives within the upper half of the target range of 60 to 85% of HRmax; duration from about twenty minutes increasing to thirty minutes per. exercise session a with 3 to 5 sessions a week.

The Maintenance Stage-The maintenance stage of the exercise program usually begins after the first six months of training. The maintenance stage typically involves exercise frequency of about 3 times a week, working within a target range of 70 to 85% of HRmax and lasting from about thirty to forty-five minutes per bout. Further improvement may be minimal, but continuing the same workout routine enables individuals to maintain their fitness levels.

MUSCULAR (ANAEROBIC) FITNESS

Resistance training of moderate intensity-sufficient to develop and maintain muscular fitness and lean body weight-is a vital part of a complete exercise prescription to create and maintain overall health. It is especially important in the obese population in order to create more lean muscle which increases basal metabolic rate and helps increase number of calories burned both at rest and during activities. The physiological benefits of resistance training also include increases in bone mass and in the strength of connective tissues.

Muscular strength and endurance are developed by the overload principle-by increasing the resistance to movement or the frequency or duration of activity levels above those normally experienced. Muscular strength is best developed by using weights that develop maximal or nearly maximal muscle tension with relatively few repetitions. Muscular endurance is best developed by using light weights with a greater number of repetitions. To realize improvement in both muscular strength and endurance, most experts recommend 8 to 12 repetitions per exercise.

ACSM GENERAL EXERCISE PRESCRIPTION FOR WEIGHT RESISTANCE TRAINING

*Perform a minimum of 8 to 10 separate exercises that train the major muscle groups. A Primary goal of the program should be to develop total body strength in a relatively time-efficient manner. Programs lasting longer than I hour per session are associated with a higher drop out rate.

*Perform one set of 8 to 12 repetitions of each of these exercises to the point of volitional fatigue.
*Perform these exercises at least 2 days per week.
*Adhere as closely as possible to the specific techniques for performing a given exercise.
*Perform every exercise throughout a full range of motion.
*Perform both the lifting (concentric phases) and lowering (eccentric phases) portion of the resistance exercises in a controlled manner.
*Hold weights firmly but not too tightly in the hand.
*Maintain a normal breathing pattern.

ACSM GENERAL EXERCISE PRESCRIPTION FOR MUSCULOSKELETAL FLEXIBILITY

Optimal musculoskeletal function requires that an adequate range of motion be maintained at all joints. Of particular importance is maintenance of flexibility in the lower back and posterior thigh regions to help prevent increased risk for the development of lower back pain.

Properly performed stretching exercises can aid in improving and maintaining range of motion in a joint or a series of joint. Flexibility exercises should be performed in a slow, controlled manner with a gradual progression to greater ranges of motion.

*Frequency-at least 3 days per week
*Intensity-to a position of mild discomfort
*Duration-10 to 30 seconds for each stretch
*Repetitions-3 to 5 for each stretch
*Type-Static, with a major emphasis on the lower back and thigh area