The training effect is a fitness term that refers to the amount of effort that an athlete must exert in order to receive fitness benefits from an exercise. Kenneth H. Cooper coined the phrase in the 1960s while working for the United States Air Force. The basic principle of the training effect is that experienced athletes will have to undergo a more strenuous workout in order to receive the same benefits that a less-experienced athlete would receive from a less-intense workout. References to the training effect are most common in discussions of cardiovascular exercise, but the term also has relevance to weight training.
The concept of the training effect depends upon a few key points. When an athlete performs aerobic exercises, the heart and respiratory muscles become stronger. Also, the athlete's blood pressure lowers, and the number of blood cells increases. The body becomes more efficient and, as a result, exercises that previously would have been very strenuous become easier and put less strain on the body. The exercises become easier, so their ability to improve the athlete's overall fitness decreases.
As a result of the training effect, athletes who want to continually improve their performance cannot continue to perform the same workouts. If they do, they will find that, over time, their overall fitness level will start to plateau. To continue to improve their fitness levels, then, athletes must perform increasingly difficult exercises.
When Cooper discovered the training effect in the 1960s, it changed the approach that most athletes took to measuring exercise. Rather than measuring the exercises that the athletes were performing, trainers began to measure traits of the athletes while performing the exercises. The Cooper test was one of the first ways that trainers did this, but trainers have found better ways of measuring aerobic performance since Cooper introduced his test in the 1960s. Measuring an athlete's maximal oxygen consumption, or VO2 Max, for instance, allows trainers to determine how much aerobic activity an athlete needs to perform in order to improve his or her overall fitness.
While most of the measurements that resulted from Cooper's research were specific to aerobic exercises, the basic concept of the training effect is relevant to weight training as well. As an athlete performs various lifts, he or she increases his or her total amount of muscle tissue and increases the efficiency of the nervous system that controls the muscles. As a result, the athlete is capable of lifting more weight, and the previous workouts will no longer provide the same benefit that they did when he or she first started performing them. This training effect results in an athlete needing to continually increase either the amount of weight or the number of repetitions in order to continue to increase his or her muscular fitness.