New research has shown one type of muscle contraction is most effective at increasing muscle strength and muscle size and rather than lifting weights, the emphasis should be on lowering them. It found those who only lowered a weight saw the same improvements as those who raised and lowered weights — despite only performing half the number of repetitions. One eccentric muscle contraction a day can increase muscle strength if it is performed five days a week..This latest study shows we can be far more efficient in the time we spend exercising and still see significant results by focusing on eccentric muscle contractions.