Monster Hamstrings from Hell!!
Most bodybuilders choose free weights over machines for maximum hamstring activation. Like the quadriceps, the hamstrings muscle group comprises four individual muscles located on the thigh. However, the anatomy and muscle architecture of the hamstrings muscle group are much more complex than those of the quadriceps. The stiff-legged deadlift is considered one of the best exercises for building massive, hanging hamstrings, however, a new study suggests that lying leg curls activate more muscle fibers in the hamstring than the still legged deadlift. This is unexpected as it often recommended to choose free weights over machines for maximal muscle recruitment.
Researchers placed electrodes all over subject’s hamstrings and measured electrical activity of the hamstrings during the performance of the stiff-legged deadlift, a hip-dominant exercise, and the lying leg curl, a knee-dominant exercise. The participants performed the stiff-legged deadlift and lying leg curl to muscular failure using a load equating to their eight repetition maximum for each exercise. Results showed that the lying leg curl elicited significantly greater muscle activation of the hamstrings compared with the stiff-legged deadlift. Athletes looking to target the hamstrings maximally should favor the lying leg curl over the stiff legged deadlift.
So does that mean that the lying hamstring curl is the best exercise for the hamstrings? Well, the lying hamstring curl is better than the stiff-legged deadlift, but it’s still not the best hamstring exercise. The latest study in the British Journal of Sports Medicine examined ten different hamstring exercises. The hamstrings are a group of four muscles on the back of the thigh. The four hamstrings muscles are: the biceps femoris (long head), the biceps femoris (short head), the semitendinosus, and the semimembranosus. The two biceps femoris muscles are located on the lateral part of the thigh. The semitendinosus and the semimembranosus are located on the medial part of the thigh.
The total volume of the medial hamstrings is greater than that of the lateral hamstrings, the lateral hamstrings are more often injured, but the medial hamstrings are more highly activated during high-speed running. Different exercises may be required to develop the medial and lateral hamstrings, and both groups should be trained for improving sprint running ability.
Here are the exercises that the researchers studied:
Bilateral stiff-leg deadlift
Unilateral stiff-leg deadlift
Unilateral bent knee bridge
Unilateral straight knee bridge
45° hip extension
Nordic hamstring exercise
At the end of the study, the researchers concluded that the hamstring should be exercised thru several different exercises rather than just one exercise. Regarding muscle recruitment during the eccentric contraction, 45° hip-extension exercise elicited the largest muscle response. The researchers concluded that hip extension exercise selectively activates the biceps femoris long head, while the Nordic curl preferentially recruits the semitendinosus.
Key Point: The hamstring should be exercised by a number of different exercises to build muscle, but the 45° hip-extension and Nordic curl are two of the best hamstring exercises that can be incorporated in the gym.