Slow speed strength training and the facts

There has been increased interest in Super-Slow® training that has led to considerable controversy among strength and fitness professionals.

Super-Slow® strength training was developed by Ken Hutchins in 1982 as a safer method for performing resistance exercise. During the past 20 years those who have attempted this style of strength training either love it (the minority) or hate it (the majority). Nevertheless, there has been increased interest in Super-Slow® training that has led to considerable controversy among strength and fitness professionals.

Let''s begin with the relationship between movement speed, muscle tension and force production. Without exception, slower movement speeds require more muscle tension and permit higher force output than faster movement speeds. Figure 1 presents a maximum effort isokinetic knee extension (Q) and knee flexion (H) at a relatively slow speed of 60º per second, a moderate speed of 90º per second, and a relatively fast speed of 120º per second. You will note that as the movement speed increases, the muscle tension (area under the force curves) and muscle force production (peak of the force curves) decreases.

Although slower movement speeds are more effective for building muscle strength than faster movement speeds, they are also much more difficult to perform. Super-Slow® strength training, with a 10-second lifting phase and a four-second lowering phase, represents an extremely slow repetition speed that most people find unacceptable as a standard exercise technique. On the other hand, if you don''t mind a little muscle discomfort you should find the Super-Slow® training protocol highly productive.

Research studies

Consider two research studies that we conducted comparing Super-Slow® and standard-speed strength training with 147 previously untrained men and women.<1> Both studies were conducted in the research centre at the South Shore YMCA, using a small class format (six participants working with two instructors). The training protocols in both studies were identical. Subjects were randomly assigned to either Super-Slow® training (one set of 13 Nautilus exercises; four to six repetitions at 14 seconds each, with 10 seconds lifting and four seconds lowering) or to standard-speed training (one set of 13 Nautilus exercises; eight to 12 repetitions at seven seconds each, with two seconds lifting, one second pause and four seconds lowering). Both groups performed essentially the same amount of exercise in approximately the same amount of training time (four to six reps at 14 seconds each required 56 to 84 seconds; 8 to 12 reps at 7 seconds each required 56 to 84 seconds).

Research results

Strength assessments were made before and after eight weeks of training in the first study and 10 weeks of training in the second study. In Study One, the subjects who performed Super-Slow® training attained 50% greater strength gains that the subjects who performed standard-speed training (see Table 1). Likewise, in Study Two, the subjects who did Super-Slow® training achieved 50% greater strength development than the subjects who did standard-speed training (see Table 2).

Two studies with almost 75 subjects each, conducted six years apart, produced similar statistically significant results. In addition, analyses by gender revealed essentially the same percentage of strength improvement for both men and women who used the Super-Slow® protocol (25%) and for both men and women who used the standard-speed protocol (44%).

From a physiological perspective, these studies indicated that Super-Slow® training is superior to standard-speed training for building muscle strength in beginning exercisers. However, from a psychological perspective there was little subject support for the Super-Slow® exercise technique. Only one participant in each study continued to train in a Super-Slow® manner after completion of the research project.

Our studies with advanced exercisers have also shown significant strength gains following six weeks of Super-Slow® training, indicating that this is an effective technique for overcoming strength plateaus.<2,3> After six weeks the subjects returned to standard-speed training for six weeks, before again performing the Super-Slow® protocol.

Practical applications

Slower movement speeds appear to be more effective than faster movement speeds for increasing muscle strength. However, the repetition speed should not be so slow that it is poorly tolerated by the participant. We have had excellent results with Super-Slow® strength training programmes lasting from six to 10 weeks in duration. However, longer periods of productive Super-Slow® training may require high levels of motivation and/or supervision by a personal trainer/instructor.

We have recently experimented with a slow strength training protocol, we call 5x5x5. Basically, the participants perform each exercise for five repetitions, using a five-second lifting movement and a five-second lowering movement. This procedure provides 50 seconds of continuous, high-effort resistance exercise, and has proven effective for both beginning and advanced subjects in our preliminary studies. Perhaps just as important, it has been well received by almost all of the participants.

Regardless of the repetition rate you prefer, use proper exercise technique and controlled movement speeds that reduce the role of momentum. Although less momentum typically means lower weightloads, this is a fair price to pay for greater strength gains and lower injury risk. As a general classification, we consider lifting movements less than two seconds as fast, lifting movements between two and six seconds as slow, and lifting movements between six and 10 seconds as very slow. Unless you are an Olympic-style weightlifter who must maximise momentum for competitive success, there is little reason to lift weights/weightstacks in less than two seconds. Beyond that, the repetition speed is up to you.

Wayne L Westcott PhD is fitness research director at the South Shore YMCA in Quincy, MA, USA. He has authored 18 books on strength training, including Specialized Strength Training and High-Intensity Strength Training.

Table 1. Changes in muscle strength for Super-Slow® and standard-speed training groups in Study One (74 subjects).

Rep Speed	Pre-Training	Post Training	Strength Gain
Standard	20.5 Kg	28.5 Kg	+ 8.0 Kg
Super-Slow®	20.3 Kg	32.3 Kg	+12.0 Kg*
*Statistically greater strength gain (P <.001).

Table 2. Changes in muscle strength for Super-Slow® and standard-speed training groups in Study Two (73 subjects).

Rep Speed	Pre-Training	Post Training	Strength Gain
Standard	26.5 Kg	33.6 Kg	+ 7.4 Kg
Super-Slow®	25.0 Kg	35.9 Kg	+10.9 Kg*
*Statistically greater strength gain (P <.001).

References

1. W Westcott, R Winett, E Anderson, J Wojaik, R La Rosa Loud, E Cleggett and S Glover 2001, Effects of regular and slow speed resistance training on muscle strength, Journal of Sports Medicine and Physical Fitness, 41: 154-158.
2. W Westcott 1996, Building Strength and Stamina. Champaign, Il: Human Kinetics.
3. W Westcott and T D’Arpino 2003, High-Intensity Strength Training. Monterey, CA: Healthy Learning.

Courtesy of Fitness Professionals UK

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