Ask Afaa

American Fitness, Jan, 1999 by Gregory L. Welch

Focusing on the Negative

If weightlifters stress the negative part of a lift (the return) is more important for muscle growth than the push, how do you acquire strength in water weight training since there is no negative resistance in water?

Philip Marmaros, Ph.D. Jerusalem, Israel

To answer this question effectively, it is important to clarify the concept of negative work and its relation to resistance training in water. Negative work, more appropriately known as eccentric muscular contraction, is the lowering of a weight against the pull of gravity. An eccentric movement in the bench or chest press would be lowering the weight to the chest. In the same example, the opposite of an eccentric contraction is a concentric contraction, which would be lifting the weight away from the chest.

Some weightlifters adopt the philosophy that separate eccentric training is an important aspect of a strength regimen. In the second edition of The Encyclopedia of Weight Training (1997), Paul Ward explains that although it assists in stimulating muscular growth, negative work does not produce strength that can be transferred to a positive or concentric movement. Brian Sharkey agrees in his book, Fitness and Health (1997), where he states that before people get excited about the minimal strength gains of eccentric training, they must understand the law of specificity. Unless a sport or job calls for letting down heavy loads, negative training will not help performance as much as regular weight training. Regular weight training would include both the eccentric and concentric contraction. It is the combination of concentric and eccentric muscle action which increases exercise efficacy, resulting in enhanced muscle strength and fiber size (O'Hagen et al., 1995).

This brings us to the second issue of strength training in water. Resistance in water is only concentric work. In other words, whereas free weights or machines involve alternate concentric and eccentric actions of the same muscle with little or no rest in between, water resistance involves alternate concentric actions of antagonist muscle groups. Each muscle group rests while its antagonist works (Harman, 1994). The lack of eccentric muscle action in water-resisted activity can build strength but would involve the same problems regarding the law of specificity. For instance, most sport and job-related activity involves eccentric work with any movement requiring a breaking action. Walking or running downhill, decelerating after a sprint, stopping the throwing arm after releasing a ball or simply setting down any object are all examples of eccentric work that we often take for granted.

It is most important when designing an individual's exercise program that many factors are considered, such as the specific objective of the training. Resistance training in water would not be my first choice for a strength modality. However, there are several other reasons that I would design a training program to be carried out in water. The initial assessment of the individual is the best place to begin and ultimately crucial in designing the most appropriate and effective exercise program.

Gregory L. Welch, M.S., is an exercise physiologist and president of SpeciFit: An Agency of Wellness in Seal Beach, California. He lectures and is published nationally regarding fitness topics focusing on special needs populations, as well as being an instructor for the senior exercise specialist certificate program at California State University, Fullerton.