Eccentric strength training is when you apply a greater load, sometimes more than your 1RM, during the negative part of a lift. You then remove the extra load before the concentric part. You can also use a spotter or an assisted machine to lighten the load during the concentric phase.
Many strength training programs designed to promote power and strength include a certain amount of eccentric training. For good reasons. Eccentric training can help promote greater strength gains. Recent research also suggests that you can use it as a tool to maximize hypertrophy.
This tool has to be used with caution, though, as eccentric training can result in excessive muscle damage. This can lead to reduced performance during the recovery period.
In a new study, 11 men with years of strength training experience performed two bench press sessions in a randomized, counterbalanced order. During one of the sessions, they performed 6 sets of 5 reps of Smith machine bench presses using an extra heavy eccentric phase (120% of 1RM). The other session was a regular high-intensity workout. Here, they used 80% of 1RM during both phases of the lifts, with the same number of sets and reps.
The results showed that the eccentric training caused a significant decrease in strength and power during the following 48 hours.
This was especially apparent in activities that require high movement speeds. Muscle power at a high speed of contraction, measured using the bench press throw, was still impaired 48 hours after the eccentric workout. This did not happen after the regular workout.
In addition, ultrasound measures revealed that the eccentric training caused significant muscle swelling that persisted throughout the recovery period. This suggests a greater inflammatory response to the eccentric training.
If you include eccentric training in your routine, make sure you get enough rest and recovery. The researchers suggest you wait at least 48 hours between eccentrically loaded training sessions to let the muscles recover properly.
Eccentric training can be a great tool to stress your muscles enough to force them to grow bigger and stronger. However, greater stress requires greater recovery.