Your muscles contract in two ways during strength training: shortening and lengthening. Most workout programs focus on the shortening, or concentric contractions of the muscles to overload the fibers and increase muscular strength. A concentric contraction, for example, is when you lift a weight during an arm curl, or when you press up a bar during a bench press. The muscles shorten as they contract and you raise the weight.
Slow Down Your Workout
An eccentric contraction happens when the muscle lengthens. This phase is when you lower the weight or return to the starting position of the exercise. An eccentric contraction occurs, for instance, when you lower the weight during an arm curl or lower the bar toward your chest during a bench press. The primary muscles of the Biceps and the Pectorals are lengthening as you lower the weight, yet they remain involved to slow down the movement and prevent you from dropping the weight. If the eccentric contraction did not occur, imagine raising the weight during an arm curl and then your hands quickly falling to your sides as you lower the weight.
Eccentric contractions also help you to slow down when running, maintain your balance when descending stairs and prevent you from dropping things when you want to slowly place them on the ground. You can take advantage of this muscle principle and use it during your strength-training sessions to increase your strength gains. It only requires a slight change to your workout focus, but you will begin to see the results and possibly, enjoy the way it makes you feel. If you’ve been missing that post-workout muscle soreness, eccentric, also known as “negative”, training can bring that back. Since it is an intense workout, the American College of Sports Medicine, ACSM, recommends resting for three to five days before completing another eccentric workout.
The goal with eccentric training is to slow down the lowering, or lengthening phase of the exercise. Count for two seconds to lift the weight and then allow four to six seconds for the lowering phase. For example, stand with your arms at your sides, palms facing forward and holding a dumbbell in each hand. Exhale, bend your elbows and within two seconds, raise the weights toward your shoulders. Pause for one second at the peak of the Biceps contraction, then inhale and slowly lower the weight as you count to six before you return to the starting position. This technique requires concentration and you may also want the assistance of a spotter if performing eccentric contractions during the bench press, French curls or squats to decrease your risk of injury.
Perform a five- to 10-minute warm-up prior to your eccentric workout to increase blood flow to the working muscles. Use proper form and decrease the weight if necessary to keep correct form. At first, complete fewer repetitions until you are comfortable with the workout. Expect to feel muscle soreness as eccentric exercise increases the production of lactic acid in the muscles.
You can also perform eccentrics on weight machines, which is beneficial for older adults or those new to strength training. Eccentrics may increase pain from arthritis, so use with caution.