Guidelines for Healthy Eating

Eating a variety of foods and maintaining an energy balance are basic guidelines for a healthy diet. Good nutrition is not complicated for those who understand these dietary guidelines.

To be properly nourished, you should regularly eat a wide variety of foods from the major food groups, selecting a variety of foods from within each group. A well-balanced diet provides all the nutrients needed to keep one healthy.

Most healthy adults do not need vitamin or mineral supplements if they eat a proper variety of foods. There are no known advantages in consuming excessive amounts of any nutrient, and there may be risks in doing so.

To get enough fuel from the food you eat and to obtain the variety of foods needed for nutrient balance, you should eat three meals a day. Even snacking between meals can contribute to good nutrition if the right foods are eaten.

Another dietary guideline is to consume enough calories to meet one’s energy needs. Weight is maintained as long as the body is in energy balance, that is, when the number of calories used equals the number of calories consumed.

The most accurate way to control caloric intake is to control the size of food portions and thus the total amount of food ingested. One can use standard household measuring utensils and a small kitchen scale to measure portions of foods and beverages. Keeping a daily record of all foods eaten and physical activity done is also helpful.

For example, a person running at 6 miles per hour (MPH) will burn 0.079 cal./min./lb. and a typical, 150-pound male will burn 11.85 calories/minute (150 lbs. x 0.079 cal./lb./min. = 11.85) or about 710 calories in one hour.

To estimate the number of calories you use in normal daily activity, multiply your body weight by 13 if you are sedentary, 14 if somewhat active, and 15 if moderately active. The result is a rough estimate of the number of calories you need to maintain your present body weight. You will need still more calories if you are more than moderately active. By comparing caloric intake with caloric expenditure, the state of energy balance (positive, balanced, or negative) can be determined.

Avoiding an excessive intake of fats is an important fundamental of nutrition.

Carbohydrates are the primary fuel source for muscles during short-term, high-intensity activities.

Avoiding an excessive intake of fats is another fundamental dietary guideline. A high intake of fats, especially saturated fats and cholesterol, has been associated with high levels of blood cholesterol.

The blood cholesterol level in most Americans is too high. Blood cholesterol levels can be lowered by reducing both body fat and the amount of fat in the diet. Lowering elevated blood cholesterol levels reduces the risk of developing coronary artery disease (CAD) and of having a heart attack. CAD, a slow, progressive disease, results from the clogging of blood vessels in the heart. Good dietary habits help reduce the likelihood of developing CAD.

It is recommended that all persons over the age of two should reduce their fat intake to 30 percent or less of their total caloric intake. The current national average is 38 percent. In addition, we should reduce our intake of saturated fat to less than 10 percent of the total calories consumed. We should increase our intake of polyunsaturated fat, to no more than 10 percent of our total calories. Finally, we should reduce our daily cholesterol intake to 300 milligrams or less.

Isometric contraction produces contraction but no movement, as when pushing against a wall. Force is produced with no change in the angle of the joint.

Isotonic contraction causes a joint to move through a range of motion against a constant resistance. Common examples are push-ups, sit-ups, and the lifting of weights.

Isokinetic contraction causes the angle at the joint to change at a constant rate, for example, at 180 degrees per second. To achieve a constant speed of movement, the load or resistance must change at different joint angles to counter the varying forces produced by the muscle(s) at different angles. This requires the use of isokinetic machines. There are other resistance-training machines which, while not precisely controlling the speed of movement, affect it by varying the resistance throughout the range of motion. Some of these devices are classified as pseudo-isokinetic and some as variable-resistance machines.

Isotonic and isokinetic contractions have two specific phases - the concentric or “positive” phase and the eccentric or “negative” phase. In the concentric phase (shortening) the muscle contracts, while in the eccentric phase (elongation) the muscle returns to its normal length. For example, on the upward phase of the biceps curl, the biceps are shortening. This is a concentric (positive) contraction. During the lowering phase of the curl the biceps are lengthening. This is an eccentric (negative) contraction.

A muscle can control more weight in the eccentric phase of contraction than it can lift concentrically. As a result, the muscle may be able to handle more of an overload eccentrically. This greater overload, in return, may produce greater strength gains.

The nature of the eccentric contraction, however, makes the muscle and connective tissue more susceptible to damage, so there is more muscle soreness following eccentric work.

When a muscle is overloaded, whether by isometric, isotonic, or isokinetic contractions, it adapts by becoming stronger. Each type of contraction has advantages and disadvantages, and each will result in strength gains if done properly.

The above descriptions are more important to those who assess strength than to average people trying to develop strength and endurance. Actually, a properly designed weight-training program with free weights or resistance machines will result in improvements in all three of these categories.

Poor body composition can cause problems in day-to-day living. People with inadequate muscle development cannot perform as well as people with good body composition. As a person gets fat, their ability to perform physically declines, and their risk of developing disease increases. Poor body composition, especially obesity, has a negative effect on appearance, self-esteem, and negatively influences attitude and morale.

The amount of fat on the body, when expressed as a percentage of total body weight, is referred to as the percent body fat.

Flexibility is a component of physical fitness. Developing and maintaining it are important parts of a fitness program. Good flexibility can help you accomplish such physical tasks as lifting, climbing, running, and hiking with greater efficiency and less risk of injury. Flexibility is the range of movement of a joint or series of joints and their associated muscles. It involves the ability to move a part of the body through the full range of motion allowed by normal, disease-free joints.

No one test can measure total-body flexibility. However, simple tests can be used to assess flexibility in the hamstring and low-back areas. These areas are commonly susceptible to injury due, in part, to loss of flexibility. A simple toe-touch test can be used. You should stand with your legs straight and feet together and bend forward slowly at the waist. A person who cannot touch his toes without bouncing or bobbing needs work to improve his flexibility in the muscle groups stretched by this test.

Stretching during the warm-up and cool-down helps you maintain overall flexibility. Stretching should not be painful, but it should cause some discomfort because the muscles are being stretched beyond their normal length. Because people differ somewhat anatomically, comparing one person’s flexibility with another’s should not be done. People with poor flexibility who try to stretch as far as others may injure themselves.

Muscular strength is the greatest amount of force a muscle or muscle group can exert in a single effort.

Muscular endurance is the ability of a muscle or muscle group to do repeated contractions against a less-than­maximum resistance for a given time.

Although muscular endurance and strength are separate fitness components, they are closely related. Progressively working against resistance will produce gains in both of these components.

Activities such as running, hiking, bicycling, swimming, cross-country skiing, rowing, stair climbing, and jumping rope place an extra demand on the cardiovascular and respiratory systems. During exercise, these systems attempt to supply oxygen to the working muscles. Most of this oxygen is used to produce energy for muscular contraction. Any activity that continuously uses large muscle groups for 20 minutes or longer taxes these systems. Because of this, a wide variety of training methods are used to improve cardio respiratory endurance.

A poorly designed and executed physical fitness program is counterproductive not only will you not get the results you expect you’ll lose your focus and motivation. A good program is well planned and organized, has reasonable yet challenging requirements, and is competitive and progressive.

Continually assess yourself to determine which specific areas of fitness you lack. Once you identify your shortcomings, modify your programs to correct the weaknesses.

Regularly measure your physical fitness level to evaluate your progress and determine the success of your program.

Ensure that the time you allotted for your physical fitness training is used effectively.

Training times is wasted by the following:

• Being unprepared or unorganized.
• Insufficient training intensity: it will result in no improvement.
• Rates of progression that are too slow or too fast.
• Extreme formality that usually emphasizes form over substance.
• Inadequate facilities which cause long waiting periods between exercises during a workout and/or between workouts.
• Long rest periods which interfere with progress.

Attaining a high level of physical fitness cannot be done simply by going through the motions. Hard training is essential.

Your objective should be to incorporate the most effective methods of physical training into a balanced program. This program should result in the improved physical fitness and an enhanced ability to perform daily life tasks.

Your level of physical fitness’ has a direct impact on your quality of life. The many environmental stresses of work, finances, relationships, and daily events in modern society underscore the important role physical fitness plays in day-to-day living. The renewed nationwide interest in fitness has been accompanied by many research studies on the effects of regular participation in sound physical fitness programs. The overwhelming conclusion is that such programs enhance a person’s quality of life, improve productivity, and bring about positive physical and mental changes. Not only are physically fit people healthier, they are also more likely to have enjoyable, productive lives.

This chapter provides an overview of fitness. It defines physical fitness, outlines the phases of fitness, and discusses various types of fitness programs and fitness evaluation. You can use this information to develop an intelligent, lifestyle-related, physical fitness program.

Physical fitness, the emphasis of this website, is but one component of total fitness. Some of the others are weight control, diet and nutrition, stress management, dental health, and spiritual and ethical fitness, as well as the avoidance of hypertension, substance abuse, and tobacco use. This website is primarily concerned with issues relating directly to the development and maintenance of the five components of physical fitness.

This website’s physical fitness training program extends to all people in all lifestyles includes all people of all ages and both sexes. Its purpose is to present a foundation to create your own physical conditioning program that will promote health and fitness throughout your life. It also includes people with limiting physical abilities who want to participate in physical fitness training.