TRX Hamstring Runner
What Is the TRX Hamstring Runner?
TRX Hamstring Runner is a compound exercise that primarily targets the hamstrings and also engages the glutes, calves and core. It is an intermediate-level movement: you lie on your back with your heels in the suspension straps, hold your hips up in a bridge, and bend one knee at a time toward your chest in a steady, alternating rhythm that looks a little like running.
The alternating pattern is what sets it apart from the two-leg TRX Hamstring Curl. While one leg bends, the other stays straight and presses its heel into the strap, so the hamstrings and glutes on that side work hard just to keep the hips up. Because only one leg supports the bridge at a time, the pelvis also wants to drop or twist toward the moving leg, and the core has to resist that. The result is a bodyweight hamstring exercise that trains strength, endurance and control together, which makes it a good fit for home and suspension circuits, or for the accessory part of a lower-body session after the main lifts.
In a study of 20 elite female track and field athletes, this same alternating suspension curl worked the hamstrings at a medium intensity, in the same band as a hamstring bridge and a leg curl done with little or no load, while a sliding leg curl ranked higher. It also worked the inner and outer hamstrings about evenly, so it is a general hamstring exercise rather than a way to single out one part of the muscle.
It suits trainees who can already hold a TRX Glute Bridge and perform smooth reps of the TRX Hamstring Curl. If the hips sag or the hamstrings cramp, build up with a regular Glute Bridge and the two-leg curl first. It is a useful addition for runners and field athletes, but it does not load the hamstrings eccentrically at long lengths, so it complements rather than replaces the Nordic Hamstring Curl.
Muscles Worked
- Biceps Femoris
- Primary
- Semimembranosus
- Primary
- Semitendinosus
- Primary
- Gluteus Maximus
- High
- Adductor Magnus
- Medium
Instructions
- Adjust the suspension straps so the foot cradles hang at mid-calf height.
- Lie on your back facing the anchor, with the straps hanging straight down over your feet.
- Place both heels in the foot cradles with your toes pointing up and your legs straight.
- Rest your arms flat on the floor beside your body, palms down.
- Press your heels into the cradles and lift your hips until your body forms a straight line from shoulders to heels.
- Keeping your hips up and level, bend one knee and draw it toward your chest until the thigh is about vertical, while the other leg stays straight.
- Straighten that leg back to the start, then bend the other knee in the same way.
- Keep alternating legs at a steady, controlled rhythm, with your ribs down and your hips level.
- After the last rep, lower your hips to the floor and take your heels out of the cradles.
Common Mistakes
Letting the hips sag
Dropping the hips between reps takes tension off the hamstrings and glutes, so keep a straight line from shoulders to heels throughout the set.
Arching the lower back
Pushing the hips up by arching the back loads the spine instead of the hips, so keep the ribs down and the core braced.
Twisting the pelvis
Letting the hip on the moving side drop or rotate each time you switch legs means the core has stopped doing its job, so keep both hips level.
Kicking instead of curling
Swinging the legs fast and sawing the straps back and forth uses momentum instead of the hamstrings, so move at a steady, controlled rhythm.
Relaxing the straight leg
The support leg should press its heel firmly into the cradle, because letting it go slack makes the hips drop and the straps swing.
Setting the straps too long
Cradles that hang too low or too far from the anchor let the feet drift, which makes the hips sag before the first rep starts.
Injuries
TRX Hamstring Runner is a low risk exercise when performed with proper technique. You lift only your own body weight, you start and finish lying on the floor, and you can stop any rep by lowering your hips. The most common problems are hamstring cramps, which happen when the muscle is fully shortened and working hard, and lower back discomfort when the hips sag or the back arches to keep them up.
To stay safe, set the straps so the cradles hang at mid-calf height directly above your feet, keep your ribs down and your hips level, and move at a steady pace instead of kicking the legs back and forth. If you cramp, lower your hips slightly, shorten the knee bend and build range over a few sessions.
To make it easier, practice the TRX Glute Bridge or the two-leg TRX Hamstring Curl, or take the straps away and use the Hamstring Bridge. To progress, slow the tempo, pause with the knee bent, raise the hips higher, or move on to the Nordic Hamstring Curl.
Stop if you feel a sharp or pulling pain at the back of the thigh, a cramp that does not release, or pain in the lower back or behind the knee. If you are recovering from a hamstring strain, wait until a clinician or physical therapist clears you for hamstring curls before adding this exercise.
- Primary Focus
- Hamstrings
- Equipment
- Suspension trainer and body weight
- Modality
- Strength
- Difficulty
- Intermediate
Alternative Exercises
Other Names for the TRX Hamstring Runner
The TRX Hamstring Runner is also known as:
- TRX Alternating Hamstring Curl
Frequently Asked Questions
- Q: How is the TRX Hamstring Runner different from the TRX Hamstring Curl?
In the TRX Hamstring Curl both knees bend together, while in the runner one leg bends as the other stays straight and holds the bridge. That makes the runner harder to keep stable, because each support leg has to hold the hips up on its own and the core has to stop the pelvis twisting.
- Q: Why do my hamstrings cramp during this exercise?
Cramping is common when the hamstrings are fully shortened and working hard, especially early on. Lower the hips a little, bend the knee less and stop the set before the cramp sets in, then add range as your hamstrings adapt.
- Q: Should I move fast, like I am running?
No. The name describes the alternating leg pattern, not the speed, and moving fast turns the exercise into a leg swing that sags the hips and saws the straps. Use a steady rhythm where you can keep your hips level on every rep.
- Q: How many reps should I do?
Two to four sets of 8 to 12 reps per leg work well for most people, counting one bend of each knee as one rep. You can also work for time, for example 30 seconds, once your form holds up for the whole set.
- Q: Will it prevent hamstring strains?
It builds hamstring strength and control, which supports injury prevention, but it does not load the hamstrings as they lengthen under tension, the way they work during fast running. For that, pair it with the Nordic Hamstring Curl.