Use heavy eccentric exercises to optimally train the hamstrings. The hamstrings are an important muscle that is often overlooked in everyday life and sports. With the right training program you can prevent injury when sprinting and improve speed.
Biomechanics of The Hamstrings
The hamstrings are one of the most commonly strained muscles in high speed sports such as soccer, rugby, football, and sprinting. The majority of hamstring injuries occur while running at maximal speeds. The hamstring experiences a high degree of stress when sprinting because it is a biarticular muscle that crosses two joints—the hip and knee and joints.
A contributing factor is that the musculotendon unit of the hamstring is at its longest during terminal swing just prior to foot strike when sprinting. Peak length is about 10 percent longer than when in an upright stance.
The hamstrings utilizes the stretch-shortening cycle when sprinting, with the muscles lengthening during the terminal swing before touchdown, switching to a shortening phase just prior to foot-strike.
During the terminal swing, the hamstring muscles have the greatest biomechanical load because each of the individual muscles that make up the hamstring reach peak strain and perform large amounts of negative (eccentric work).
The hamstrings is three separate muscles that work together. Interestingly, a movement analysis found that the three hamstring muscles experience the terminal phase of sprinting differently:
- the biceps femoris has the largest peak strain (12 percent increase in length from upright stance)
- the semitendinosus has the greatest lengthening speed
- the semimembranosus produces the highest force and performs the largest amount of positive and negative work.
The biceps femoris is the most commonly injured hamstring muscle. Researchers believe this is due to the fact that the biceps femoris experiences a high degree of muscle damage during the eccentric motion.
Train The Hamstrings With Heavy Eccentrics
The best way to prepare the hamstrings to handle heavy loads is to train eccentric exercises. Eccentric exercises emphasize the lengthening portion of a lift, either with heavier loading or an extended tempo. For example, you could use a longer eccentric tempo in typical hamstrings exercises.
Good ones to start with are Nordic eccentric hamstring exercises paired with lying hamstring curls. Perform these exercises using a 4-second lowering, eccentric motion and a 1-second concentric motion.
Progress to more advanced eccentric hamstrings exercises:
Use a 6- to 10-second tempo on Good Mornings, Romanian Deadlifts, and Reverse Hyperextensions to maximally train the hamstrings.
Training the hamstrings with eccentric exercises is worth the effort because it will promote structural balance and help prevent injury to this oft injured muscle.