Concentric vs Eccentric
Resistance training involves two main types of movements, concentric and eccentric:
Concentric movement is when the muscle shortens while producing force (contracting the muscle). This happens when you are raising the weight during a biceps curl.
Eccentric movement is when the muscle lengthens while producing force. For example, when you’re lowering the weight back down during a biceps curl.
Both movements are said to lead to increased hypertrophy/muscle mass. Some evidence suggests that eccentric training promotes muscle mass more than concentric. This may be due to a more rapid response of muscle building (anabolic) signaling and induced muscle damage. Loading differences between the two movements can contribute to the small advantage of eccentric lifting. During eccentric lifting one often tend to use a heavier weight of around 10-15% concentric 1RM.
Concentric movements are great for increasing power and reduce the prevalence of DOM’s whereas eccentric training will increase strength and lead to an increase in DOM’s
Although both training methods have there benefits, it is always good to include both training modes into your workouts