From Charles Poliquin
Varying the speed with which you perform your lifts can help you lose fat and build muscle. Playing with lifting speed, or tempo, is an effective way to change the stimulus to the muscles so that you break through plateaus and drop those excess pounds.
A new Spanish study that was presented at the International Conference on Strength Training in Norway shows the effect of various lifting speeds. Researchers used trained men and had them do six squat workouts with different rep/set schemes and varied tempos. After each workout they tested the degree of neuromuscular fatigue and metabolic buildup of lactate and ammonia.
The workout schemes were as follows: 3 X 8 reps with 60 percent 1RM load at maximal velocity, 3 X 8 reps with 70 percent 1RM load at half speed, 3 X 6 reps with 70 percent 1RM load at maximal speed, 3 X 6 reps with 70 percent 1RM at half speed, 3 X 3 reps with 80 percent 1RM load at maximal speed, and 3 X 3 reps with 80 percent 1RM load at half speed.
Results showed that metabolic stress was much greater when the trainees lifted as fast as possible. Blood lactate and ammonia were significantly higher when training at maximal velocity compared to the intentionally slower half speed for all rep/set schemes. Metabolic stress was greatest following the explosive 3 X 8 reps at 60 percent 1RM load, followed closely by the 3 X 6 reps at 70 percent 1RM at full speed. This indicates that explosive contractions trained for a higher volume with moderate loads can promote the dual goals of fat loss and muscle development.
Neuromuscular fatigue showed a similar training effect: The higher volume, maximal velocity training led to greater reductions in countermovement jump height than the slower speed lifts. Maximal intended lifting velocities demand the recruitment of fast motor units, which produce higher lactate levels for both metabolic and neuromuscular benefits.
This study is a snapshot of the effect of lifting tempo to elicit strength and body composition changes. A second study measured how lifting speed affects energy expenditure. Researchers compared an explosive squat tempo with a 2-second squat tempo for 4 sets of 8 reps at 60 percent 1RM.
Results showed that the rate of energy expenditure was increased by 11 percent during the squats in the explosive condition compared to the controlled condition. The amount of calories burned in the hour after the workout was also 5 percent higher following the explosive squats.
Take away the understanding that programing your lifting speed allows you to take precise control of the training stimulus to achieve dramatic improvements in body composition. The benefits of tempo training extend beyond simply helping you lose fat and burn more energy. Ballistic contractions such as Olympic lifts, squat jumps, or bench throws will allow you to bring about more central nervous system adaptations as well.
Mazzetti, S., et al. Effect of Explosive Versus Slow Contractions and Exercise Intensity on Energy Expenditure. Medicine and Science in Sports and Exercise. 2007.
Sanchez-Medina, L., et al. Acute Metabolic and Mechanical Response to Resistance Training Performed at Maximal Intended Vs. Half-Maximal Lifting Velocity in the Squat Exercise. International Conference on Strength Training. 2012. Oslo: Norway.