Genghis Fitness · Training Guides

Hamstring Workouts: The Complete Training Guide for Strength, Size, and Injury Prevention Using Evidence-Based Exercise Selection

Updated 2026  |  By Team Genghis Fitness  |  25 min read

The hamstrings are the most undertrained muscle group among athletes who squat and deadlift regularly, yet they are simultaneously among the most commonly injured muscles in sport. This apparent contradiction resolves when you understand the anatomy: the hamstrings have distinct functional roles in hip extension and knee flexion that are addressed by completely different exercises, and most athletes train only one of these functions adequately while entirely neglecting the other. The result is an imbalanced hamstring that is relatively strong through the deadlift hip extension pattern but weak and vulnerable through the knee flexion range that sprint deceleration and cutting movements demand.

This guide covers the complete hamstring training framework: the anatomy that explains why different exercises produce different adaptations, the specific exercises that research has identified as most effective for each function, how to structure hamstring training within a complete lower body program, and how to address the flexibility and strength deficits that predispose athletes to hamstring strain injuries.

Hamstring Anatomy: Two Functions, Two Training Priorities

The hamstrings consist of three muscles: the biceps femoris (long and short heads), the semimembranosus, and the semitendinosus. All three muscles cross the knee joint (they are knee flexors) and all except the short head of biceps femoris cross the hip joint (they are also hip extensors). This dual-joint structure means the hamstrings are under tension in two very different movement contexts.

Hip extension function: During deadlifts, Romanian deadlifts, hip thrusts, and good mornings, the hamstrings work primarily as hip extensors. The knee remains relatively extended and the primary challenge is maintaining length under load through the hip hinge. This is the function that squatting and deadlifting athletes train most, and where hamstring strength is typically adequate in experienced lifters.

Knee flexion function: During sprinting (especially deceleration), cutting movements, and knee flexion exercises like leg curls and glute-ham raises, the hamstrings work primarily as knee flexors. The short head of the biceps femoris only crosses the knee, making it active only in this function. Research consistently finds that the ratio of knee flexor (hamstring) strength to knee extensor (quadriceps) strength is a significant predictor of hamstring strain injury risk, with athletes whose hamstring-to-quadriceps ratio falls below 0.6 at substantially elevated risk. A study published in the British Journal of Sports Medicine confirmed that hamstring strength deficits, particularly in eccentric knee flexion, are among the strongest predictors of subsequent hamstring strain in team sport athletes.

The Best Hamstring Exercises: Evidence-Based Selection

Romanian Deadlift (Hip Extension, Lengthened Position)

The Romanian deadlift is the gold-standard hip extension hamstring exercise because it loads the hamstrings in a lengthened position (hips hinged with straight legs) where the muscle is under the greatest stretch. Training muscles under load in their lengthened position produces superior hypertrophy compared to exercises that primarily load shortened positions, as established in research published in the Journal of Strength and Conditioning Research. The RDL movement: stand with the bar in a hip-width grip, maintain a neutral spine and slight knee bend throughout, hinge from the hips to lower the bar along the legs until a strong hamstring stretch is felt (typically when the bar reaches mid-shin level), then drive the hips forward to return to standing. The stretch position is the stimulus; do not rush through it. Heavy RDLs requiring a solid grip benefit from lifting straps to prevent grip from limiting the hamstring training load.

Nordic Hamstring Curl (Eccentric Knee Flexion)

The Nordic hamstring curl is the single most evidence-supported exercise for hamstring injury prevention. The movement requires the athlete to kneel with ankles anchored (under a barbell, by a partner, or in a machine), then slowly lower the torso toward the floor under eccentric hamstring control, resisting gravity through the full range. It trains the hamstrings eccentrically through the knee flexion range at long muscle lengths, precisely the strength quality that is deficient in athletes who predominantly squat and deadlift. A landmark randomized controlled trial published in the American Journal of Sports Medicine found that Nordic hamstring curls reduced hamstring strain injury rates by 65 percent in professional soccer players, the largest injury prevention effect documented for any single exercise intervention. Including 2 sets of 5 to 8 reps of Nordic curls weekly provides meaningful protective benefit.

Leg Curl (Machine Knee Flexion)

Both lying and seated leg curl machines train the hamstrings through the knee flexion range with adjustable loading. The seated leg curl is preferred over the lying variant by several EMG studies because the hip flexion in the seated position pre-stretches the rectus femoris, allowing greater hamstring activation by reducing reciprocal inhibition. Both variations are valid and complementary. Leg curls are the most practical way to progressively overload the knee flexion function of the hamstrings with controlled incremental weight increases, making them an essential component of complete hamstring development. 3 to 4 sets of 10 to 15 reps.

Glute-Ham Raise

The glute-ham raise requires the athlete to anchor the feet in a glute-ham developer (GHD) machine, extend the hips, and then flex the knees to raise the torso. Unlike the Nordic curl, the GHD allows both the eccentric and concentric phases to be trained under control. The exercise loads the hamstrings as both a hip extensor and a knee flexor simultaneously, making it one of the most comprehensive single hamstring exercises available. It requires access to a GHD machine but is worth the effort. Start with bodyweight and progress to added load (weight plate held at chest) as the bodyweight version becomes achievable for 3 sets of 10.

Kettlebell Romanian Deadlift and Single-Leg RDL

Single-leg RDL variations train the hamstrings unilaterally, exposing side-to-side strength asymmetries that bilateral exercises mask. Most athletes have a stronger and a weaker hamstring, and bilateral RDLs allow the stronger side to compensate. Single-leg work addresses this imbalance. The movement is identical to the bilateral RDL but performed on one leg, with the free leg extending behind for counterbalance. The balance demand makes lighter loads necessary but the unilateral challenge produces functional strength development that transfers to running and cutting movements.

Structuring a Complete Hamstring Training Program

A complete hamstring program addresses both functional categories in every training week. Structuring these exercises within a lower body program that also includes squats, hip thrusts, and quad isolation work requires thoughtful sequencing to manage fatigue and recovery.

Exercise	Function	Sets x Reps	Frequency
Romanian Deadlift	Hip extension	3 to 4 x 8 to 12	2x per week
Nordic Hamstring Curl	Eccentric knee flexion	2 to 3 x 5 to 8	2x per week
Leg Curl (seated or lying)	Knee flexion	3 x 10 to 15	2x per week
Single-Leg RDL	Hip extension, unilateral	2 to 3 x 10 per leg	1x per week

Order within a session: perform RDL and other hip hinge hamstring exercises after squats but before isolation exercises. Nordic curls create significant delayed onset muscle soreness in athletes new to the movement; introduce them with low volume (1 set of 5) and progress gradually over 4 to 6 weeks before reaching full volume.

Hamstring Flexibility and Its Role in Injury Prevention

Hamstring stiffness (insufficient flexibility at the required range) is a contributing factor to strain injury risk, but its relationship with injury is more complex than simply “tighter equals higher risk.” Passive flexibility alone does not prevent injury; what matters is the combination of adequate flexibility to allow the movement range required by the sport, and sufficient strength through that full range to resist the forces generated. Athletes who are flexible but have weak hamstrings in the lengthened position are not protected. The flexibility work in our hamstring stretch guide and the strength work in this article work together to address both variables. For lower body training with cable machines that adds ankle strap hamstring curl variations, the ankle straps enable prone and standing cable leg curls that complement machine leg curls effectively.

Frequently Asked Questions

Do Deadlifts Train the Hamstrings Enough on Their Own?

Conventional deadlifts train the hamstrings primarily as hip extensors with the knee remaining relatively extended. They do not train knee flexion hamstring function, they do not develop eccentric strength in the lengthened position to the degree that RDLs and Nordics do, and they do not expose side-to-side asymmetries. For athletes whose only sport is powerlifting, deadlifts provide substantial hamstring development as part of the compound pattern. For athletes who also run, sprint, or play field sports, supplementary hamstring work addressing knee flexion and eccentric strength is necessary for both performance and injury prevention.

How Long Does It Take to See Hamstring Development?

Strength improvements from hamstring training become measurable within 4 to 6 weeks of consistent training at adequate volume. Visible hypertrophy changes (increased size and definition in the posterior thigh) become apparent after 8 to 16 weeks for most athletes. The hamstrings respond to training with similar timelines to other lower body muscles, but because they are often undertrained relative to the quadriceps, athletes who begin a comprehensive hamstring program frequently notice relatively rapid initial strength gains as they develop the neural connection to recruit these muscles effectively.

What Should You Do If You Experience a Hamstring Strain?

A hamstring strain requires cessation of the activity that caused the injury and medical assessment for severity grading. Grade 1 strains (mild muscle fiber disruption) typically resolve with 1 to 2 weeks of relative rest and gentle progressive loading. Grade 2 (partial muscle tear) requires 4 to 8 weeks of progressive rehabilitation. Grade 3 (complete tear) is a surgical consideration. Self-diagnosing the severity is unreliable; persistent pain, swelling, or bruising warrants professional evaluation. Return to full training after a hamstring strain should be guided by pain-free range of motion, symmetric strength compared to the uninjured side, and sport-specific movement quality, not simply time since injury.