Hamstring injuries in runners: Causes, recovery and strength exercises

By Henry Howard

A sudden grab at the back of your thigh mid-stride is one of the most frustrating moments a runner experiences. Hamstring injuries sideline everyone from hobby joggers to weekend warriors to elite sprinters. I've seen athletes face down time due to such injuries, as an RRCA-certified running coach who regularly coaches 12 to 20 runners.

The good news is that most hamstring problems respond well to smart, progressive rehab and a few strength habits can dramatically lower your risk of a repeat. The downside is hamstring injuries have a reputation for coming back.

Recently, I have been sidelined by injury.

I first felt pain and discomfort in my glute medius, which I covered in another post, and the issue progressed to affect my hamstring and tensor fasciae latae (TFL), a small, short muscle located on the outer, front-upper side of the hip. After visits with my doctor and physical therapist on the same day last week, I have confirmed it is a strain, not tear, and that a weak hamstring is the underlying cause.

(Please note: This article is for general education and is not medical advice. If you suspect a significant injury, see your doctor or physical therapist.)

This guide covers hamstring injuries in runners, including how common they are, how to recognize one, what causes them, how to recover and the exercises that build a more resilient hamstring.

What are the hamstrings?

Let’s start out with the basics about hamstrings.

Your hamstrings are three muscles running down the back of the thigh: the biceps femoris, semitendinosus and semimembranosus. They attach at the sit bone (ischial tuberosity) at the top and cross behind the knee at the bottom. They extend the hip, bend the knee, and, crucially for runners, act as a brake.

For runners, late in the swing phase of every stride, the hamstrings lengthen under load to slow your lower leg before your foot hits the ground. That combination of stretching and force is exactly why they are so injury-prone.

How common are hamstring injuries in runners?

Hamstring strains are among the most common muscle injuries in sports that involve sprinting and high-speed running. They show up regularly in distance runners too, most likely due to overuse injuries.

They show up most frequently during speed work, hill sprints, races with a fast finish and any surge at the end of a hard run.

Two patterns are worth knowing:

• Acute strains happen suddenly, usually at higher speeds.

• Chronic or overuse problems, such as proximal hamstring tendinopathy (pain where the tendon attaches near the sit bone), build slowly and are common in distance runners and masters athletes.

  
  

Recurrence is also notoriously high. Many people return to running as soon as walking feels fine, before the muscle can handle speed again, and reinjure it. This is likely what elongated my recovery time, even though I was working with a physical therapist on strengthening work, scraping and other recovery methods.

How to identify a hamstring injury

Hamstring injuries are typically graded by severity. For me, it is a mild strain, where I felt the pulling sensation during running, but rarely during walking, cycling or other movements.

• Grade 1 (mild): A small number of muscle fibers are overstretched or pulled. You feel tightness or a pulling sensation, and you can often keep walking normally. Strength is all or mostly intact.

• Grade 2 (moderate): A partial tear. There is sharp pain, noticeable weakness, and often swelling. Walking may be uncomfortable and running is not possible.

• Grade 3 (severe): A complete or near-complete tear of the muscle or tendon. Expect immediate, intense pain, possibly a pop, significant bruising, and difficulty walking or bearing weight.

A pain that is more of a deep ache near the sit bone, which worsens with sitting, hill running or speed work, points more toward tendinopathy than a strain.

Symptoms of a potential hamstring injury

• Sudden sharp pain in the back of the thigh, sometimes with a feeling of a "grab," "pull" or "pop."

• Tenderness when you press on the muscle

• Bruising in the back of the thigh or behind the knee, often appearing a day or two later.

• Swelling.

• Weakness or tightness when bending the knee or extending the hip.

• Pain when stretching, climbing stairs or sitting for long periods (especially with tendinopathy).

• Pain that eases with walking but returns when you try to run faster.

See a medical professional immediately if you heard or felt a pop, cannot walk without significant pain, have extensive bruising, notice numbness or tingling down the leg, or the pain is near the sit bone and severe. A severe tendon avulsion can require surgery, and early assessment matters.

Common causes and risk factors for hamstring injuries

Hamstring injuries rarely have a single cause. They usually result from several factors stacking up.

• Previous hamstring injury. This is the strongest predictor of another one.

• Speed work and sprinting. High-velocity running puts the hamstrings under their greatest stretch and load.

• Fatigue. Tired muscles absorb force poorly. Many strains happen late in a race or workout.

• Weakness or imbalance. Weak hamstrings relative to the quadriceps, or weak glutes and core, push the hamstrings to do more than they can handle.

• Poor warm-up. Going straight to fast running without preparing the muscle raises the risk.

• Sudden jumps in training. Rapid increases in volume, intensity or hill work are classic triggers.

• Overstriding. Landing with the foot far in front of the body increases hamstring stress.

• Age. Risk rises as we get older, which makes this especially relevant for masters runners.

• Tight hip flexors or stiff lumbar spine and pelvis. These can alter running mechanics and overload the hamstring.

• Sitting a lot. Long hours seated can leave the hamstrings and glutes underused.

Best recovery methods for hamstring injuries

Recovery depends on the grade of the injury, but the same principles apply.

1. The first few days

Protect the area and avoid anything that provokes sharp pain, but do not rest completely. Current thinking has moved away from strict rest toward gentle, early movement as pain allows.

• Avoid fast running, aggressive stretching and heavy loading.

• Walk as comfortably as you can. Short, pain-limited walks promote healing.

• Ice or cold packs can help with comfort in the first days, though they are not essential.

• Compression and elevation can reduce swelling if it is significant.

• Talk with a pharmacist or doctor before taking anti-inflammatory medication, since some sports medicine guidance suggests avoiding it early in muscle healing.

2. Early rehab (days to weeks)

Once walking is comfortable, begin gentle isometric exercises, such as light bridge holds, and progress gradually. Exercises prescribed by a PT are also useful in this part of the recovery process. Cross-training that does not aggravate the injury, such as swimming, pool running or easy cycling, can maintain fitness.

3. Progressive strengthening

Strength work is the center of recovery. Move from isometric holds to controlled movement (bridges, hip hinges), then to heavier and more demanding exercises.

I highly recommend working with a physical therapist so they can assess the injury, prescribe specific exercises to address it and demonstrate the proper routine to avoid another injury.

4. Return to running

A general guide for readiness before returning to running:

• Walking and daily activity are pain-free.

• You can perform single-leg bridges and hip hinges without pain and with equal strength to the other side.

• Pain-free jogging is the next step, followed by gradual increases in speed. Strides and sprints should come back last.

  
  

Start with easy runs on flat ground, gradually add volume before intensity, and keep speed work and hills out of the plan until the leg feels normal. A running coach and/or physical therapist can help you test strength and set return criteria, which is particularly helpful for higher-grade injuries or repeat problems.

Typical timelines for mild strains often take one to three weeks, moderate strains several weeks to a couple of months, and severe injuries or tendinopathy can take several months. Everyone heals at their own pace.

Exercises to strengthen the hamstrings

(Last updated: Oct. 17, 2026)

These are examples of exercises that build strength in the way the hamstrings are used in running. Again, it is best to work with a PT to get specific recommendations to heal your injury and correct any muscle imbalances you may have.

Start light, move pain-free, and progress slowly. If an exercise causes sharp pain, stop and return to recovery.

1. Glute bridge (and single-leg bridge)

Lie on your back with knees bent and feet flat. Press through your heels, lift your hips until your body forms a straight line from shoulders to knees, hold briefly, then lower. Progress to single-leg versions or a bridge with feet elevated. Try: 2 to 3 sets of 10 to 15 reps, or 3 to 5 holds of 20 to 30 seconds early in rehab.

2. Sliders

Stand with weight on your injured leg, then slowly slide the opposite foot to the side away from your body, then back and pause, then slide the foot behind your planted leg and return to starting position. Sliders on a smooth floor or dragging a furniture slider with your foot work well. Try: 2 to 3 sets up to 10 reps.

3. Romanian deadlift (RDL) and single-leg RDL

Hinge at the hips with a flat back and soft knees, lowering a weight or just your hands toward the shins, then drive your hips forward to stand. The single-leg version improves balance and tests side-to-side differences. Try: 3 sets of 6 to 10 reps, adding load gradually.

4. Hamstring curls with stability ball

Lie on your back with heels on a stability ball, lift your hips and curl your heels toward you, then slowly extend legs forward. Try: 2 to 3 sets of 8 to 12 reps.

5. Nordic hamstring curl

Kneel with your ankles anchored (I have a device that makes this easier), then slowly lower your torso forward as far as you can control, bracing yourself against the ground with your hands. This eccentric exercise is among the best studied for reducing hamstring injury risk, but it is demanding. Introduce it only once you are pain-free with the exercises above. Try: 2 to 3 sets up to 10 slow reps, building up gradually. Ease in to avoid severe soreness.

6. Marching bridge and glute-focused work

Strong glutes share the load with the hamstrings. Add side-lying leg raises, clamshells, step-ups, and lateral band and monster walks. Try: 2 sets of 10 to 15 reps.

Weekly approach

Two strength sessions per week is a good starting point for most runners, though some of these exercises would work well for a pre-run warmup.

As a full set, this workout is best done on the day of a hard workout or long run; just be sure to get the run completed first.

How to prevent hamstring injuries

• Warm up with dynamic movements such as leg swings, marching, skips and similar movements before each run.

• Keep strength training a permanent part of your routine, not just a rehab tool.

• Increase speed work, hill work and mileage gradually.

• Respect fatigue and cut back on hard efforts when your legs feel heavy.

• Treat small tightness as a warning sign rather than something to run through.

• Allow for recovery, especially as you age. Masters runners often do well with fewer hard days and more consistent strength work.

• Check your stride. If you overstride, increasing cadence slightly can reduce stress on the hamstrings.

Frequently Asked Questions: Hamstring injuries for runners

Question: How long does a hamstring strain take to heal? Answer: It depends on severity. Mild strains often improve in one to three weeks, moderate strains typically take several weeks to a couple of months, and severe tears or chronic tendon problems can take months. Returning too early is a common reason injuries linger or recur.

Question: Can I keep running with a mild hamstring strain? Answer: It depends on pain and function. If you can run easily with no more than very mild discomfort that does not worsen and does not change your stride, short easy runs may be possible, but sharp pain, limping or a worsening ache means stop. When in doubt, cross-train and have it assessed.

Question: Should I stretch a pulled hamstring? Answer: Aggressive stretching in the early days can aggravate the injury. Gentle, pain-free mobility is fine, but strengthening is generally more valuable than stretching during recovery.

Question: Is it a hamstring strain or sciatica?

Answer: Strains cause local pain, tenderness and often bruising in the muscle. Sciatica or nerve-related pain tends to involve burning, tingling or numbness that travels down the leg and may be linked to the lower back. If you are unsure, see a clinician.

Question: What is the difference between a hamstring strain and tendinopathy? Answer: A strain is usually a sudden injury to the muscle. Tendinopathy develops gradually, causes pain near the sit bone, and is often worse with sitting, hills and speed work. Both benefit from progressive loading, but the plan differs.

Question: Why do hamstring injuries keep coming back? Answer: The most common reasons are returning to running too soon, not rebuilding strength, and going back to speed work without a gradual progression. Previous injury is also the strongest risk factor, which makes consistent strengthening so important.

Question: Are masters runners at higher risk? Answer: Risk generally increases with age, and tendons and muscles recover more slowly. That does not mean masters runners cannot train hard. It means warming up, building strength and allowing recovery become even more important.

Question: Do Nordic hamstring curls really prevent injuries? Answer: Research, particularly in team sports, supports Nordic curls as an effective way to reduce hamstring injuries. They are intense, so build up gradually and make sure you are fully recovered before adding them.

Question: When should I see a doctor or physical therapist? Answer: See a professional if you felt a pop, cannot walk normally, have significant bruising or swelling, notice numbness or tingling, or are not improving after a week or two. Pain near the sit bone that persists is also worth a professional evaluation.

Final thoughts

Hamstring injuries are common, but they are not inevitable. Respect the early healing phase, rebuild strength before speed, and keep a couple of hamstring and glute sessions in your weekly routine. A patient return to running is almost always faster than a rushed one that ends in another setback.