Principles of training (part 2)

Overload principle

The basis for the overload principle is that adaptations will not occur unless the demands of training are greater than the usual demands made on a particular physiological mechanism. When you increase the usual demands on as system, we say that the system is overloaded.

Although simple in definition, the overload principle is complex in application. Although the demands of the training must be sufficient to stimulate adaptation, they cannot be excessive or the training effect will be lost through injury or failing adaptation. 

Progression principle

The progression principle is the systematic process of increasing the overload of the training in order for further adaptations and improvement in performance to take place. Swimmers cannot train at the same speed week after week and expect to continue improving their aerobic capacity or other physiological capacities. They must gradually increase their training intensity throughout the season to provide a progressive overload that will stimulate further improvements.

Coaches and athletes should be very careful when they are designingtheir training progression because the nature of the desired training effect can be distorted by overloading incorrectly or by trying to progress too rapidly. 

The most common form of training used by swimmers is interval training, a method that lends itself to the application of progressive overload. Interval training involves completing a certain number of swims or repeats with a period of rest after each swim. Four variables govern the construction of each set:

1. the number of repeats in the set,
2. the distance of each repeat,
3. the rest interval between each repeat, and
4. the speed of each repeat.

Swimmers can manipulate interval training variables to continue overloading various aspects of their physiological systems in three ways:

1. By increasing the speed of swimming repeats (training intensity)
2. By increasing the number of repeats or the distance of each repeat in a repeat set (training volume)
3. By decreasing the rest interval between repeats (training density)

Each way has its strengths and weaknesses :

Training intensity

Strengths

• most direct method for improving competition times
• best method for improving sprint speed
• one of the best methods for improving aerobic and anaerobic muscular endurance
• physiological adaptations occur more rapidly than they do with any other method

Weaknesses

• least effective for improving aerobic capacity because increasing swimming speeds cause a shift in ATP recycling away from aerobic metabolismand toward anaerobic metabolism
• physiological improvements tend to plateau quickly
• emotionally stressful

Training volume

Strengths

• good procedure for improving aerobic capacity, aerobic muscular endurance, and anaerobic muscular endurance
• physiological adaptations tend to continue at a steady rate for a longer time than they do with other methods
• least stressful method physically and emotionally

Weaknesses

• has little if any value for improving sprint speed
• can become boring
• requires progressively more practice time

Training density

Strengths

• very effective for improving aerobic and anaerobic muscular endurance
• can be effective for improving aerobic capacity if sets are designed and conducted properly
• very challenging and motivating form of training

Weaknesses

• procedure has little value for improving sprint speed
• can interfere with improvements in aerobic capacity if rest intervals are shortened before aerobic adaptations allow the athlete to swim the repeats with less rest and not produce severe acidosis
• difficult to administer to large groups in crowded swimming lanes