For many years it was thought that resistance training was inappropriate for many athletes. The belief was that weightlifting exercises would slow athletes down, and the increase in muscle size would cause athletes to loose joint flexibility and become muscle bound. This myth was discarded in the 1960s after coaches and exercise researchers discovered that strength and power training are beneficial for almost all sports and activities.

The formal definition of muscular strength is the ability of a muscle or group of muscles to generate maximal force. The test for finding what your maximum strength is referred to as the one-repetition maximum, or the 1-RM. To determine your 1-RM, select a weight that you know you can lift or press at least once. After a proper warm-up, perform a few repetitions. If you are successful, add some more weight and try again. Repeat this until you are unable to move the weight more than one repetition. The weight you are able to do only one repetition with is considered your 1-RM and is a measurement of your muscular strength. Record this number in a journal, and upon the completion of thirty days of training repeat this test and see how much your strength has improved.

Strength allows your muscle to generate force in short bursts, relying on anaerobic capacity (See Chapter 10 for more on anaerobic exercise.)

Stronger muscles are generally larger and require stronger ligaments (connective tissue) to support them and avoid injuries.

While you can be too flexible, it's hard to imagine a situation where too strong is ever a problem unless your strength is uneven in your body. Each protagonist muscle has an antagonist muscle. Chest muscles overdeveloped relative to the back muscles may exhibit rounded shoulders, shortened pectorals, and otherwise poor posture. While you may want to focus on particular areas, remember that it is essential that you develop your entire body.

As mentioned earlier, muscular strength is essential for a high level of performance in many sports and activities. There are many other health factors that come along with strength training as well. Strong muscles help keep joints strong, making them less susceptible to sprains, strains, and other injuries.

Strength training also promotes good posture. Your life is full of activities that pull your shoulders forward, causing a slumping or slouching in the upper back. Working at a computer, driving a car, sitting and reading a book — anything you do that utilizes your arms and hands in front of your body causes gravity to pull you forward and down. This can cause all kinds of neck and back pain, which can then lead to other postural problems and injuries. An adequate strength-training program can eliminate and prevent many of these problems if done properly.