Vary Tempo To Maximize Muscle & Strength Gain
by Charles Poliquin
Train with a variety of training tempos to get the greatest muscle and strength gains. Tempo training or varying the time your muscles spend performing a lift is one of the most important, but commonly overlooked, programming parameters to get maximal results. Varying tempo is a “big bang for your buck” strategy that will allow you to achieve goals and overcome plateaus that hold you back.
A new study in the European Journal of Applied Physiology
tested the effect of a variety of tempos and training loads in a group of untrained women—a population on which there is a lack of research into the effect of varying tempo on muscle and strength development.
The following training protocols were compared: a traditional strength protocol that used a fairly heavy weight of 80 to 85 percent of maximal for all exercises using “normal” speed exercises with 1 to 2 second contractions for both the eccentric and concentric phases of the lift; a slow speed protocol that had participants lift to failure with a weight of 50 to 60 percent of maximal for all exercises with a varied tempo of 10 seconds for the concentric phase and 4 seconds for the eccentric phase of the lift; and a muscle endurance protocol that also used the “normal” tempo with weights that were 50 to 60 percent of maximal.
Both the slow speed and the traditional strength protocols resulted in significant muscle building. The muscular endurance protocol resulted in no muscle-building response and no change in muscle size. The slow speed protocol increased the size of both the slow type I fibers and the faster type IIA fibers, while the strength protocol produced the greatest increase in overall muscle fiber growth and the largest increase in type IIA and IIX muscle size. The type IIA and IIX fibers are the fast-twitch fibers that are needed for power and speed, and if the goal is muscle building, you want to target them because they have a greater capacity to grow than type I fibers.
Even though the slow speed protocol used a “slow” and “steady” protocol, it did produced a large increase in the percentage of type IIA fibers that are needed for speed, strength, and power. This indicates that a slow tempo can provide a significant stimulus to the muscle and appears to recruit higher threshold motor units that can trigger adaptations, which you would not suspect to see from the light load used.
Overall, the strength protocol produced the greatest muscle adaptations with
a 38.8 percent increase in muscle fiber size compared to a 10 percent muscle growth in the slow speed protocol. Slow speed training did build muscle, which would likely lead to increases in strength, but the heavy strength protocol produced the greatest stimulus to the muscle, which may indicate that in untrained individuals training the fast motor units is optimized at near maximal forces and faster velocities.
Previous studies have shown that increasing the amount of time spent on the eccentric phase of the lift rather than the concentric phase is more effective at maximizing muscle development and recruitment of the high-threshold motor units. A recent study compared the effect of a 1-second tempo with a 6-second tempo and found that the rate of protein synthesis was two-fold greater following the slow tempo protocol.