Friday, July 5, 2013

Hamstring Training For Bodybuilding

Hamstring Training For Bodybuilding

Fully developed hamstrings are often the difference between good legs and great legs. When a bodybuilder hits a side pose, it is the hamstrings that catch the judge’s attention: and why wouldn’t they, a massive rounded mound of flesh hanging of the rear of the leg is enough to make anyone pay respect. Additionally, striated hamstrings can be the icing on the cake in an array of back poses.
Impressive as they are, hamstrings are definitely not one of the more glamorous muscle groups and seldom, if ever, do we hear people discussing training them. Even rarer is to see people training them correctly. Most people throw in a couple of sets of leg curls after they have just annihilated their quads and expect such a meagre effort to stimulate some hypertrophic adaptation. Unfortunately, this approach simply will not work. Hamstrings, like all other muscle groups, require a detailed plan of attack that encompasses an array of exercises and careful manipulation of the variables (reps, sets and rest etc).

Basic Anatomy And Physiology

The hamstrings consist of three muscles: the biceps femoris, semitendinosus and the semimembranosus. The biceps femoris is located to the rear and on the outside of the thigh. It has two heads; one originates on the pelvis and one originates on the femur. This muscle is responsible for bending the knee, extending the hip, and rotating the leg outwards, especially when the knee is bent.
The second muscle is the semitendinosus. This muscle is located on the rear and in the middle of the thigh. It lies directly above the semimembranosus and inside of the biceps femoris. The semitendinosus is responsible for bending the knee, extending the hip and rotating the knee inwards when the knee is bent.
The third muscle of the hamstring group is the semimembranosus. This muscle is located to the rear and towards the middle of the thigh. It lies directly under the semitendinosus and has the same muscle action.

Advanced Anatomy And Physiology

The hamstrings consist of three muscles, which are as follows:
Biceps Femoris (biceps = two & femoris = femur) - The biceps femoris originates on the ischial tuberosity (long head), linea aspera and distal femur (short head). It inserts into the head of the fibula and lateral condyle of the tibia. It is responsible for the following muscle actions:
  • knee flexion,
  • hip extension, and
  • external rotation of the femur when the knee is flexed.
Semitendinosus (semi = half & tendinosus = tendon) – the semitendinosus originates on the ischial tuberosity and inserts on the medial aspect of the upper tibial shaft. It is responsible for the following muscle actions:
  • knee flexion,
  • hip extension, and
  • medial rotation of the femur.
Semimembranosus (semi = half & membranosus = membrane) – the semimembranosus originates on the ischial tuberosity and inserts on the medial condyle of the tibia. It has the same muscle actions as the semitendinosus.
Ok, enough of the technical stuff. You now know the three muscles that make up the hamstrings, their origin and insertions and the muscle actions they each perform. 
The following table identifies exercises for the biceps femoris and the percent (out of 100) EMG activity:
Exercise
% EMG
Standing leg curl
82
Lying leg curl
71
Romanian deadlift
63
Seated leg curl
58

In addition to EMG studies, MRI has also been used to determine how the biceps femoris responds to other various exercises. The results are as follows:
  • Bodyweight squats – the biceps femoris is used minimally but improves with smith machine squats.
  • Leg press – with feet high the biceps femoris has limited use; however, when the feet are low, it contracts with moderate intensity.
  • Stiff legged deadlift – the biceps femoris contracts moderately during hip extension.
The following table identifies exercises for the semitendinosus and membranosus and the percent (out of 100) EMG activity:
Exercise
% EMG
Standing leg curl
88
Lying leg curl
79
Romanian dead lift
70
Seated leg curl
63

The semitendinosus and membranosus although used in squatting and pressing movements, only contract minimally. Maximum recruitment of these muscles occurs during the seated leg curl.

The Final Word

The results indicate that the standing leg curl is the exercise of choice for maximally recruiting the biceps femoris. This muscle when developed will enhance the lateral sweep of the leg when viewed side on. The seated leg curl will have the greatest effect on the semitendinosus and membanosus, which form the bulk of the hamstring. So, for complete development, ensure you use a combination of the aforementioned exercises; however, if you for whatever reason had to chose just one, I would suggest using the standing leg curl.
As always, the muscle prioritisation principle should be utilised if your hamstrings are a lagging body part. I would suggest either allocating one of your weekly sessions to just training hamstrings or pair them up with another muscle group such as back. A second session could be performed after quad training for additional stimulation.
Ensure to have at least 48 hours recovery between sessions. Complete hamstring development will compliment the calves and quadriceps and will ensure you are well on your way to achieving symmetry, balance and proportion.

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