There are numerous training philosophies in the fitness industry. From books and magazines to videos and the Internet, the information can be overwhelming. Some work best for strength, others for size. Some for cuts, some for speed. Some for sports, some for fitness. Some for hard gainers, some for beginners. Even if you have time to peruse all of them and adequate knowledge of training science to make informed choices, uncertainty as to which is best can still paralyze you. Science, then, must guide you. After all there is really only one science. But all too frequently, science is misinterpreted, which leads to confusion.

There are well-documented training principles that are important in judging the merits of any training system. There are at least seven overlapping principles upon which all systems must rely if optimum effectiveness in training outcomes is to be expected. Most (but not all) of the training systems popular in current muscle magazines adhere only in part to The Seven “Granddaddy” Laws. What determines whether a training system is more or less effective than another lies in how these laws are implemented, how they are used to the best advantage of the trainee and whether or not they are even considered.

1. Principle of Individual Differences

This principle is an acknowledgment that we all have different genetic blueprints. David Q. Thomas, Ph.D. stated, “We all will have similar responses and adaptations to the stimulus of exercise, but the rate and magnitude of these changes will be limited by our differing genetics. Some are fast responders and others are slow responders. Some have the capacity to reach elite status and some do not. If we have everyone perform the same exercise program, they will all not receive the same benefits at the same rate or to the same extent. This is an important principle to teach to people wishing to start an exercise program or to youngsters just coming into sports. There are two reasons: 1) so they can set realistic goals, and 2) so they do not get frustrated when they do not see miraculous changes in their bodies or performance.”

International Sports Sciences Association (ISSA) 8th Edition Text