Many combine all of the major leg muscles into one overall intensive workout but anyone, whose goal is to build some serious muscle, or shaped and toned hamstrings, and then maximum activation of the hamstrings is required. The common overall ‘leg day’ session is flawed in its ability to meet this requirement.
Firstly, it is important to remember that the hamstring muscles have multiple sections, all with different needs in order to make them fire effectively. Consequently, by fatiguing all of the leg muscles within one session the agonist or antagonist are going to suffer in terms of energy and sufficient exercise management. For example, if the quadriceps are trained before the hamstrings then energy levels will already be depleted through quadricep dominant exercises such as back squats.
Arguably, the hamstrings are still getting a workout through these combined sessions, and depending on the overall goal and intensity, good results can be elicited. However, these results are limited, as per the example, EMG activity during numerous squat variations and loads have been found to have minimal effects on the hamstrings compared to the quads, leaving the potential of the muscles contained and under used.
The hamstrings are a collective set of three muscles. These include; the biceps femoris with a long head and cross sectional area and short head with a short cross sectional area (also known as the lateral hamstring muscles). These are capable of knee flexion only.
The medial muscles of the hamstrings include the larger semimembranosus and with a slightly smaller cross sectional area, the semitendinosus muscle. These have the ability to both flex the knee and extend the hip.
This is important to know as exercise modifications should be based on the individual makeup of the three muscles and their abilities. Angles, repetitions and training type can then be attributed to make it an effective, balanced hamstrings workout.
With these actions available at both the hip and knee joints, we can focus in on the fact that the hamstrings are a set of bi-articulate muscles; that is, they rely on the attachments to both the hip and knee joints in order to perform knee flexion and hip extension.
Well, what is often found is that the medial muscles are over dominant, over developed and generally activated more on a daily basis. This means that the lateral muscles can often suffer as a result, causing the aesthetic look of the hamstrings, to appear smaller with a lack of overall width. Not to mention the reduction of strength and power output potential by ignoring these lateral portions. So, by including more exercise variety to target these regional needs and abilities we have the tools to work the hamstrings effectively to the max.
Let us step back to the actions of the bi-articular muscles. When force is applied to both of these joints at the same time, the overall movement will be weakened and compromised. However, by restricting the use of one joint it allows the effort to be taken by the other. In other words, focus in on choosing multi-angled exercises for the upper and lower portions of the hamstrings. This then allows more muscle isolation to ensure that the workout is really worth your time.
Starting with the lower section of the muscles, we should choose exercises that include knee flexion. Staple exercises such as hamstring curls fit this requirement. These exercises are generally done in a variety of positions, including standing, seated and lying in a prone position. However, it is the positioning of the body during these exercises that make a difference to the muscles overall ability to target each area in isolation.
Tests have proven that it is not one sole angle, or prime exercise that can illicit enough EMG activity for the hamstring muscles to be trained entirely. Instead, a collective effort of multiple angles is required to ensure the specific activation of each muscle within the trio.
For example, an upright standing hamstring curl allows too much movement allowance for the rest of the body, which I am definitely guilty of when the weight is slightly beyond my capabilities.
Tip 1: Standing hamstring curls on the cables are more effective if the body is bent forwards at a 45 degrees, to isolate the hamstring in the hip flexed position.
What I have also experienced myself and seen with others in more ‘old school gyms’ is the detrimental and uncomfortable positioning of a flat surfaced machine to perform lying hamstring curls. Here the hips are allowed to remain in an extended position, which then limits contraction, rather than the modern version where the machine is angled. This change in machine construction is going back to the point on bi-articulate muscles, and the need to flex the hips to enable maximum flexion of the knees.
Ok, so how can we better adapt our hamstring curls?
The body positioning on the seated hamstring curl machine places you in an upright position, allowing for a comfortable 90o flexion of the hip joints. This enables isolated flexion of the knees in order to maximally challenge the lower portion of the hamstrings. For further isolation ensure the hips are strapped or held down to keep them out of the equation and to avoid the body lifting during the exercise. Create added time under tension here by pausing at maximum peak contraction before the slow eccentric phase.
During lying or seated hamstring curls, we can also utilise different angles to ensure all three sections are worked for muscular balance. By rotating the legs and feet inwards, the inner portion of the lateral hamstring muscles take the workload, whereas an external rotation of the legs will focus on the outer lateral muscles, and a parallel position on the medial muscles.
Tip 2: Do four sets of these as mechanical drop sets to really stimulate the muscle fibres.
They hurt but they work… yes, glute-ham raises also need to be included as a priority. A study by Ebben et al compared the EMG activity of different hamstring exercises and this came out on top. Whilst they do contradict the need to isolate the joint activity, by putting the effort on the eccentric lifting of the body, knee flexion and hamstring contraction is optimised.
Now let’s bring the gastrocnemius into the equation. During the knee flexion part of the leg curl if the feet are plantar flexed the bi-articular gastrocnemius is partially disabled due to its short muscle fibre length. However, when dorsiflexed it can allow the hamstrings to generate more force. As you are more than likely aware, we are generally stronger on the eccentric phase of a movement. Bearing in mind the effect of plantarflexion on isolation, using this information will make your hamstrings fire on every rep.
Tip 3: When curling in a parallel position, dorsiflex on the concentric phase and plantar flex on the eccentric phase for even more hamstring power and isolation!
The focus for these exercises is hip extension. To maximally target this the hamstrings need to be removed from their role as knee flexors. As the glutes and erector spinae are also utilised here a higher repetition range can be used to make sure those hamstrings are blasted hard! Exercises such as Good Mornings, cable pull throughs, kettlebell swings and deadlifts utilise these capabilities to build and tighten the glute/hamstring tie in.
Tip 4: Deadlifts using a hex bar can be effective here as it takes the strain off the lumbar spine and allows for a heavier load to be lifted in a more balanced position.
Play with your angles here - turn the feet out and widen your stance to hit those outer lateral muscles.
The physiology of the hamstrings varies between its individual muscles, however a balance can generally be seen between type I and type II muscle fibres (Dahmane et al. 2006). However, one size does not fit all so this can also vary depending on an individual’s genetics. A combination of repetition ranges, number of sets, set types and loads could therefore be used (see my tips for examples). Extended sets in particular can be used to cover all ground, using strength-endurance to fully fatigue the hamstrings. This means high loads at a minimum of 70% of 1RM maintained throughout sets to create complete muscular exhaustion. Do this by flexing or lifting explosively then lowering slowly to create high-powered yet controlled time under tension for the benefit of both the mixture of fibre types and the larger cross sectional areas. For the same reasons, heavy compound movements such as elevated power cleans (on a step) are also ideal to add into your customized programme. This exercise powers through the CNS to recruit more muscle fibres as quickly as possible during the explosive movement, whilst amplifying muscle damage through the slow active tension of the stretched eccentric phase.
Tip 5: Use a golden oldie! Lunges can also create a larger degree of damage to the upper lateral portion, whilst adding the benefit of plyometric shock and explosive power. This means big dynamic steps!
Don’t ignore muscles, three is a crowd so take the time to target them one by one, fatiguing them completely using a variety of repetition ranges and resistance training methods. Volume and intensity is key. Try 4-5 sets of exercises, favoring shorter 8-10 reps for all knee flexion exercises and 10-12 or even up to 20 reps for hip flexion movements and watch those results! Try these variations and hopefully science will speak for itself.
If you would like to know more about muscles, our Core Training CPD course provides you with the knowledge and skills you'll need to prescribe safe, effective and challenging exercises for your clients.
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