Engaging in a well-designed exercise program can provide a myriad of health benefits.
Canadian physical activity guidelines, put out by the Canadian Society for Exercise Physiology, recommends 150 minutes of moderate to vigorous-intensity aerobic physical activity per week as well as muscle and bone strengthening exercises two times per week — from brisk walking to running. Muscle and bone strengthening exercises include weight-bearing activities which require force to be produced against resistance, either body weight or an external resistance.
The Health Benefits of Exercise
It is well accepted that engaging in regular physical activity provides many health benefits and improves one’s quality of life.
Physical activity has the ability to prevent or delay:
- Heart disease
- High blood pressure
- Certain types of cancer
- Type 2 diabetes
- Overweight and obesity
- Loss of physical function
- Premature death
And can lead to improved:
- Mental health (morale and self-esteem)
- Bone density
- Body image
So how does physical activity provide all of these benefits? To answer this question we first have to understand the different functions of exercise.
Functions of Exercise
Engaging in physical activity creates a stress on the body. If the stress is great enough to cause a stress response to occur, but not so great to cause injury, the body will adapt in a way that makes it better able to manage this type of stress in the future. Different types of exercise create different types of stress, and therefore, the resulting adaptations are specific to the particular type of exercise.
While all forms of exercise have effects on the body as a whole, it is easier to understand exercise by first separating it into distinct functions, then re-combining them to assess specific forms of exercise. For this purpose, I will be considering functions of exercise using these 7 distinct categories: cardiovascular fitness, reduction in body fat, muscular strength, muscular endurance, flexibility (mobility), balance, and coordination.
Cardiovascular fitness refers to the health and function of the heart and blood vessels (arteries and veins). Cardiovascular exercise includes any type of exercise, which raises heart rate for a prolonged period of time (e.g. running, jumping jacks). The heart is a muscle and adapts to this stress by getting bigger and stronger. A stronger heart is able to pump more blood and sustain a given exercise intensity for a longer period of time.
Short-term increases in blood pressure that occur while performing cardiovascular exercise improves blood vessel health; mainly by improving elasticity and by other hormone-mediated processes. Exercise bouts lasting at least 20 minutes in length while maintaining an elevated heart rate are the most effective for improving cardiovascular fitness.
Reduction in Body Fat
Reductions in body fat are commonly observed during an exercise program. This is because body fat is used as fuel during exercise, at varying levels of efficiency based on the type of exercise performed. The most efficient form of exercise for burning body fat is moderate to vigorous intensity cardiovascular activity sustained for a prolonged period of time.
Any form of exercise, which acts to raise one’s heart rate for a prolonged period of time, will burn fat. The specific type of activity largely doesn’t matter; it’s the elevation in heart rate, which is important.
Muscular strength refers to the force production capacity of muscle. Strength is often measured by an all out 1-repetition maximum of a resistance exercise (e.g. maximum leg press). Performing resistance exercises creates a stress on the muscles involved and the body adapts by building these muscles bigger and stronger. This adaptation only applies to the specific muscles involved in the exercise (e.g. biceps after dumbbell curls).
The most important factor needed to improve muscular strength is increased muscular tension over time. Increasing muscular tension generally requires greater amounts of weights to be lifted. This is referred to as the “principle of progressive overload”. This principle states that for continued increases in muscular strength to occur, a progressively greater load must be lifted over time.
Whereas muscular strength is the amount of weight that can be lifted once, muscular endurance refers to the number of repetitions that can be performed with a sub-maximal load (e.g. maximum repetitions of the lunge exercise). Muscular endurance is improved by utilizing higher repetition resistance exercises (15-25 reps) and usually results in a feeling of “the burn”. Muscular endurance and strength are related but not interchangeable. That is to say, increases in muscular strength will always increase muscular endurance but increases in muscular endurance may not necessarily increase muscular strength.
Flexibility is the property of muscles, which allows them to lengthen, and mobility refers to the ability to utilize the full range of motion of a joint (e.g. full squat). Flexibility can be improved in a number of ways including static and dynamic stretching. Static stretching refers to passive stretching in a fixed position for a period of time (generally at least 30 seconds). Dynamic stretching is an active form of stretching which involves body movement through a full range of motion (e.g. arm circles).
Balance is the ability of the body to be stable in different positions. Static balance refers to stabilization during still body positions, and dynamic balance refers to the ability to control movements without falling over. Balance is controlled by the brain and nervous system and, like any other skill requires practice to improve. Static balance is improved by maintaining difficult positions while remaining still and dynamic balance is improved by mastering challenging movement patterns.
Coordination, as the name implies, refers to one’s ability to coordinate movement of their body parts in space. Like balance, coordination is controlled by the brain and nervous system and requires practice to improve. Developing the coordination necessary to complete specific movements requires practice in those specific movements. The more movement patterns a person masters, the easier it is for them to learn other movements. This includes movements as complicated as gymnastics or as simple as walking without losing balance.
Creating a Comprehensive Exercise Program
A well-designed exercise program incorporates all of the functions of exercise in the most efficient and effective way possible to achieve the desired results. Since individuals have different fitness goals, the priorities emphasized in different programs vary, but all exercise programs include a combination of these functions. Below I will outline the most efficient way to combine these functions in an exercise program. The recommended routine consists of 3 parts: steady-state cardio, a stretching routine, and a weight-training program.
Steady-state cardio is any form of activity, which acts to raise one’s heart rate for longer than 20 minutes. Common examples are jogging, exercise classes, biking, jump rope, and various sports. A moderate to vigorous intensity is best, usually resulting in heavy breathing and sweating. This form of exercise effectively fulfills two of the functions of exercise: cardiovascular fitness and reductions in body fat. Steady state cardio should be performed at least 3 times per week, with greater amounts contributing greater health benefits.
A stretching routine will improve flexibility. Static stretches should be performed daily until the desired flexibility is achieved, each session lasting 10-30 minutes. Once the desired level of flexibility is achieved, the frequency of static stretching sessions can be cut to 3 or more times per week. Dynamic stretches should be performed before weight training and other exercises.
A weight training routine will improve the remaining functions of exercise: muscular strength, muscular endurance, balance, and coordination. Weight training can also maintain a certain level of flexibility. To improve muscular strength the routine should employ the “principle of progressive overload” by increasing the weights lifted over time.
This requires the use of “heavy” weights lifted in the 1-15 repetition range. “Heavy”, of course, is relative to the individual’s own strength level, and lifting heavy should never take precedent over learning proper form. Muscular endurance will be improved by including in the program some higher repetition exercise in the 15-25 repetition range.
Selecting exercises, which require balance and challenging movement patterns, is very important. This generally necessitates incorporating standing free-weight exercises as the main exercises in a program. There are many different types of exercises, which fall into this category, and exercise selection depends on factors such as equipment availability and personal preference.