Fitness and Exercise Explained

[Ryan]

This is going to be a sticky thread that I will use (over time) to discuss what general physical fitness is, what exercise is, and how we evaluate ourselves to achieve various health goals.

 

People should feel free to ask questions, but keep them pertinent to the material present at the time of your question. Questions should be about the material, not about you. This is a discussion on physiology and muscular kinetics, not an individual training thread.

[Ryan]

When one talks about fitness, there are actually 5 areas of general physical fitness. These attributes apply to any activity and are specific to none. I shall delineate and describe them.

 

 

Muscular Strength - the force output capability of the musculature of the body.

 

Muscular Endurance - the ability for the muscular system to repeatedly perform a submaximal task.

 

Cardiovascular Ability - the ability for the cardiovascular system to deliver fuel/oxygen and remove waste products.

 

Flexibility - the range of motion through which the joints of the body can move without injury.

 

Body Composition - the ratio of bodyfat to lean body mass, particularly muscular mass.

[Ryan]

I shall now discuss the criteria by which the 5 areas of general fitness are improved.

 

Muscular Strength - The basic criteria are overload (higher than normal output requirement) and progression (increasing requirements over time).

 

Muscular Endurance - This is influenced by a combination of muscular strength and metabolic adaptation. Increased muscular strength means a given task is now a smaller portion of maximal output. Increased metabolic adaptation means the body can regenerate energy more quickly for a given level of activity.

 

Cardiovascular Ability - This is influenced by the volume of blood the heart can deliver and the volume of oxygen the lungs can deposit in the blood.

 

Flexibility - The basic criteria is loading a joint through its fullest safe range of motion.

 

Body Composition - The major factor here is quantity of bodyfat, with quantity of muscle mass being secondary.

[Ryan]

I shall now discuss to what degree the areas of general fitness can be improved and how feasible it is to measure them.

 

Muscular Strength - Muscular strength has the greatest degree of potential for improvement of all the areas. It is essentially impossible to measure absolute strength, but it is very easy to measure relative changes in strength.

 

Muscular Endurance - Muscular endurance has a moderate degree of potential. It is difficult to accurately measure, but relative change can be noted. Strength is discussed above; measuring improvements in energy regeneration is not feasible since this occurs at a cellular level.

 

Cardiovascular Ability - Cardiovascular ability has a fairly small potential for improvement. The heart has slight potentials for increased chamber size and fraction of blood sent out compared to the amount brought in per beat (ejection fraction). The maximum amount of oxygen the lungs can pass is mostly genetically fixed and not subject to noteworthy change.

 

Flexibility - Flexibility has a moderate degree for potential improvement. It is the easiest to measure of all the 5 areas.

 

Body Composition - Body composition has a moderate to strong potential for improvement. Both bodyfat and muscle mass levels are very difficult to measure in absolute terms. Bodyfat can be fairly easily gauged in terms of relative change. Change in muscle mass is slighty more difficult and less accurate, as it must be extrapolated from other body composition information.

[Ryan]

There are as many ideas and prescriptions of "exercise" as there are "experts" in the field. Various individuals and organizations will state various things to categorize or identify activities, but hardly any of these sources can provide a precise, concrete definition of exercise. It is important to have such a definition by which any activity can be evaluated.

 

 

Exercise is:

 

An activity that overloads all of the major muscle structures of the body through a full range of motion to the point of significant fatigue.

 

 

I have denoted key terminology here for further explanation.

 

Overload - a demand beyond the typical/prior degree of demands placed on a given system.

 

Major Muscle Structures - The muscle groups that account for the most significant (in size and involvement) musculature in the body, which are the hips, thighs, back, and chest (in order of significance).

 

Full Range Of Motion - The greatest amount of joint motion possible without subjecting the body to injury.

 

Fatigue - Reduction in muscular output capacity, also known as inroad.

[Ryan]

I shall explain the basic tenets of proper strength training. This will lead to an explanation of why proper strength training is the only activity that fits a rigorous, scientific definition of exercise.

 

There are 4 tenets to proper strength training: intensity, brevity, infrequency, and safety.

 

 

Intensity - Intensity is a term that refers to the degree of muscular output relative to the maximum possible output at a given time. Proper strength training requires a high degree of intensity. This means pushing your body VERY hard (new trainees build up to this during an introductory period). Often this means exerting oneself such that no further voluntary motion is possible. This point is commonly called "failure," which is when you can no longer move the resistance.

 

Brevity - When training with high intensity, it is neither desirable nor POSSIBLE to train for a long period of time. You have a finite amount of energy, so you can't go forever at high output. Each training session should last no more than an hour, with most people falling in the 20-40 minute range. Training is built around movements that incorporate large amounts of muscle mass, known as compound movements or multi-joint movements. These are: squat, deadlift, leg press, chin-up, pulldown, row, pullover, bench or chest press, dip, overhead press. There are variants on many of these and not all are necessarily part of a given routine. 1 or 2 movements are chosen for each major muscle group. Additional specific movements can be added, but will be supplementary to the core training. Little or no rest is taken between sets.

 

Infrequency - Proper strength training does NOTHING for your body directly. It is technically a stressor - a NEGATIVE thing. Training wears your body down, which stimulates it to adapt. In order to garner benefits, the body must be left alone to undergo adaptation. This is why training sessions are done with at least 48 hours of rest. Most people will optimally train at 3-5 days per session.

 

Safety - Although last, this is the most crucial element. One of the main goals of strength training is to make the body MORE resistant to injury. It would make no sense to train in a fashion that puts oneself at significant risk. ALL movements are to be performed in GOOD form through a full range of motion. New trainees will spend about 4 weeks learning proper form and technique as they build intensity. There is no excuse to let form slip in order to perform more repetitions. Furthermore, all repetitions are done in a SLOW, CONTROLLED fashion. Safety is increased because the speed of the repetition is lower. This means the force involved to get the repetition started (and stopped) is lower; force is what causes injury. Intensity is also improved because a slower repetition has less momentum. This means you must generate a more consistent amount of force to perform a repetition.

[Ryan]

It is important to evaluate any activity against the definition of exercise and the components of general fitness. This allows us to determine the value of a given activity. I shall do so for proper strength training (as previously described).

 

 

Overload - Training to a high degree of intensity, at or near muscular failure, provides a very high degree of overload on the systems of the body.

 

Major Muscle Structures - Proper strength training incorporates movements that use all of the major muscle structures of the body.

 

Full Range Of Motion - Proper strength training uses the fullest safe range of motion possible for the movements chosen and applies overload through the entire range.

 

Fatigue - Training at or near the point of failure ensures that the muscular system has fatigued to a significant degree.

 

 

 

Muscular Strength - The basis for all progress is improvements in strength. It is easily measurable and proper strength training incrementally and consistently increases the load over time, thus meeting the progressive overload requirements excellently.

 

Muscular Endurance - Both muscular strength and metabolic adaptation are factors here. Muscular strength is handled above. Metabolic adaptation refers to the ability for the muscular system to regenerate energy (ATP). To improve the ability of the cellular structures to regenerate ATP, one must make significant demands on the muscular system such that the energy stores are rapidly depleted. Proper strength training places very high demands on the muscular system, which means very high demands on the ATP regeneration process.

 

Cardiovascular Ability - Although the cardiovascular system has little potential for improvement, it can be achieved. Since very high demands are placed on the muscular system, the cardiovascular system must act to support these high demands with oxygen, fuel, and waste removal. A high demand on the muscular system NECESSARILY causes a high demand on the cardiovascular system.

 

Flexibility - Training through a full range of motion promotes flexibility by improving muscular and connective tissue strength through the entire range of motion. This creates better joint stability which allows for fuller joint movement.

 

Body Composition - Proper strength training does little to affect bodyfat levels, since it burns few calories compared to what bodyfat stores. However, proper strength training promotes gains in muscle mass better than any other activity. This causes an increase in overall metabolic needs by 30-50 calories per day per pound, simply for existence. Metabolic increases are useful for employing effective fatloss strategies.