The Hamstring Muscles
The hamstrings are three muscles running down the back of the thigh. The biceps femoris — with its long and short heads — is the largest and forms the outer portion. The semitendinosus runs down the middle and inner side. The semimembranosus is the deepest of the three, sitting beneath the others on the inner thigh. All three share two functions: they flex the knee and they extend the hip. This is why the hamstrings need both curling movements and hinging movements to be fully trained — the curl works the knee flexion, the hinge works the hip extension. Training only one pattern leaves half the muscle undertrained.
The Muscle Group Nobody Trains
You cannot see the hamstrings. They sit behind you, invisible unless someone else is watching — and in most gyms, nobody is watching the leg area because nobody is in the leg area. The hamstring machine is consistently the emptiest piece of equipment in any commercial gym. Walk in on any day and you might find one person using it, loading it with 80 kilograms they cannot control properly, grinding out half-range reps with no understanding of what the muscle actually does. That is the full extent of hamstring training in most facilities.
There is nothing glamorous about lying face down on a machine and curling your legs. It does not appear on social media. It does not make the arms look bigger or the chest more impressive. It is purely functional, purely honest training for a muscle group that almost nobody prioritises. Which is precisely why the people who do train it properly look and move differently from the ones who do not.
Why They Matter — More Than You Think
The hamstring is the brake for the knee. Where the quad pulls the leg into extension, the hamstring controls that movement and protects the knee joint under load. When the hamstrings are significantly weaker than the quadriceps — which is the case for almost everyone who trains chest and arms and skips leg day — the knee joint is less stable, more vulnerable to injury and more likely to cause problems over time. Hamstring strains are the most common acute sporting injury in football, basketball, sprinting and most other sports that involve explosive movement. A stronger hamstring handles that load. A weak one gives way.
This is why quads and hamstrings are always trained together on the same day. Not because it is convenient. Because they are opposing muscle groups that work in balance, and training one without the other creates exactly the imbalance that leads to injury. Leg day means legs — front and back.
How It Started
Playing football and basketball from an early age meant training legs properly long before most people in a gym would consider it. In the early days, when the gym was busy and the benches and machines were all taken, the leg area was always free. Nobody wanted to be there. It was partly shyness, partly convenience — but it turned out to be the right instinct. The leg section being empty was the best thing that could have happened. The habit of training hamstrings alongside quads was built early and has never stopped.
Three Exercises — Train With the Quads
Lying leg curls and standing leg curls cover the knee flexion function of the hamstring from two slightly different positions. Good mornings cover the hip extension function with a deep, controlled stretch that finishes the session properly. After squats and lunges, the hamstrings will already be working. These three exercises finish them off completely. There is no need for more.
Lying Leg Curl
The foundation of hamstring training. Face down on the machine, curl the legs toward the glutes, lower with control. Full range of motion — all the way up, all the way down. After a session of squats and lunges the hamstrings are already warm and partially fatigued, which means the weight does not need to be high. Focus on the contraction at the top and the stretch at the bottom. This exercise done after heavy quad work will make itself felt for the next two or three days. Three to four sets of ten to twelve reps.
Standing Leg Curl
The standing version of the curl changes the position of the hip, which changes the portion of the hamstring being emphasised. Standing upright rather than lying prone engages the upper hamstring and the area where the hamstring meets the glute more directly. Not every gym has a standing leg curl machine — the old standalone machines are less common now — but when available it is a genuine addition alongside the lying version. Three sets of ten to twelve reps.
Good Mornings
The finish. Barbell across the upper back, hinge forward at the hips with a slight bend in the knees, feeling the stretch through the hamstrings at the bottom, drive back up through the glutes. The good morning trains the hip extension function of the hamstrings — the part that curling movements cannot reach — and produces a deep stretch that properly closes out a leg session. Very light weight. The stretch is the point. Three sets of ten to fifteen reps. Occasionally these were done first — but that was rare, and the lying curl was always the anchor of the hamstring work.
Also Worth Knowing — Romanian Deadlift
The Romanian deadlift is the other major hip hinge for the hamstrings — bar in hand, hinging at the hips with a soft knee bend, feeling the stretch down the back of the legs and driving back up through the hips. It loads the hamstrings under more tension than the good morning and allows heavier progressive loading over time. If the good morning is the stretch-focused finish, the Romanian deadlift is the loaded hinge that builds hamstring strength and thickness. The two can be alternated from session to session, or the Romanian deadlift used as a direct replacement when more loading is wanted.
