The Most Injury-Preventing Exercise in Sports Science
Hamstring strains are the most common muscle injury in field and court sports — accounting for up to 37% of all injuries in professional soccer and representing a recurring nightmare for sprinters and footballers. The Nordic hamstring curl (NHC), also called the Nordic hamstring exercise (NHE), has the strongest evidence base of any single injury-prevention exercise.
A landmark 2011 RCT by Petersen et al. published in the American Journal of Sports Medicine enrolled 942 elite male soccer players. Teams that performed the Nordic protocol had 51% fewer hamstring injuries overall and 65% fewer recurrent injuries compared to control teams. A 2019 Cochrane-style systematic review of 8 RCTs (n=8,459 athletes) confirmed a relative risk reduction of 0.49 — a 51% reduction in injury incidence.
Biomechanics: Why It Works
The NHC is an eccentric-dominant exercise. During the lowering phase, your hamstrings are the only thing stopping gravity from slamming your face into the floor — they are working maximally under active lengthening conditions. This is precisely the mechanical environment in which hamstrings tear during sprinting (late swing phase, hamstrings lengthening while contracting at high speed).
Key Mechanisms
- Fascicle length increases: Eccentric training with the hamstrings in lengthened positions increases muscle fascicle length. Longer fascicles act like longer springs — they can absorb more energy before failing. A 2010 study (Brughelli et al.) found NHC training increased biceps femoris fascicle length by 13.3%.
- Peak torque at longer lengths: Untrained hamstrings produce peak force at short muscle lengths. NHC training shifts the torque-angle curve so peak force occurs at the longer lengths relevant to sprinting.
- Hamstring-to-quad ratio: Conventional knee curl machines train hamstrings concentrically (shortening), which poorly replicates sprint demands. Nordic curls build eccentric hamstring strength that better balances the quadriceps.
How to Do the Nordic Hamstring Curl
Setup
You need your ankles securely anchored close to the floor. Options:
- Partner kneels and holds your ankles down
- Nordic curl board (dedicated device with foot anchor)
- GHD (glute-ham developer) machine — lower yourself from the hip pad
- Under a heavy barbell secured in a rack
- Door anchor with ankle straps (floor-level attachment)
Technique
- Kneel on a padded surface with ankles anchored
- Keep your hips fully extended (body in a straight line from knee to shoulder)
- Cross your arms across your chest or hold them slightly out
- Initiate the movement by slowly lowering yourself toward the floor — fight the fall with maximum hamstring engagement
- When you can no longer resist, catch yourself with your hands in a push-up position
- Push back up using your hands to assist, then use a hip-hinge to return to the start
- The eccentric phase (lowering) is the point of the exercise — make it last 3–5 seconds
Critical mistake: Hinging at the hips as you lower (raising your glutes, shortening the hamstring). Keep your body straight from knee to shoulder throughout.
Progressive Protocol
The Petersen (2011) protocol that produced the 51% injury reduction is well-validated and practical:
| Week | Sessions/Week | Sets | Reps |
|---|---|---|---|
| 1–2 | 3 | 2 | 5 |
| 3–4 | 3 | 3 | 6–8 |
| 5–6 | 3 | 3 | 8–10 |
| 7–10 | 2–3 | 3 | 10–12 |
| Maintenance (season) | 1 | 3 | 8–10 |
DOMS warning: The first week of Nordic curls produces severe delayed onset muscle soreness — worse than almost any exercise. Athletes who have never done them should start with assisted negatives (using arms to help return) and very low volume. Start in the off-season.
Progressions by Difficulty
| Level | Variation | Notes |
|---|---|---|
| Beginner | Assisted Nordic (push-up help) | Lower slowly, push up aggressively |
| Intermediate | Full Nordic, 3–4 reps | No arm assist on eccentric |
| Advanced | Weighted vest or plate held at chest | Adds load for strength gains |
| Elite | Arms behind head, 8+ slow reps | Full difficulty, maximal fascicle stimulus |
Integration Into Your Training Program
- Placement: After main lifts, before accessory work. Never before sprinting or heavy squatting — the fatigue and DOMS will affect performance and injury risk acutely.
- Frequency: 2–3x/week during off-season preseason, drop to 1x/week in-season for maintenance.
- Pairs well with: Romanian deadlifts (concentric-focused), hip thrusts (glutes), Copenhagen adductor exercises (groin injury prevention complement).
Best Equipment for Nordic Hamstring Curls
Nordboard / Nordic Hamstring Curl Board Most Effective
Dedicated Nordic curl boards anchor your feet at adjustable heights, making the exercise accessible at home without a partner. Look for padded knee rest, secure foot anchor, and non-slip base. The specialized angle and padding make form consistency much easier to achieve than improvised setups.
Shop Nordic Curl Boards on AmazonSunny Health & Fitness Glute Ham Developer Home Gym Option
A GHD machine enables proper Nordic curls plus glute-ham raises and back extensions in one piece of equipment. More versatile than a dedicated Nordic board. Requires more space but offers superior exercise variety for home gym setups.
Shop GHD Machines on AmazonProFitness Ankle Strap with Door Anchor Budget Setup
A floor-level door anchor with padded ankle straps can simulate the Nordic setup when used at the base of a door or secured under a heavy piece of furniture. Best for beginners testing the exercise before committing to dedicated equipment.
Shop Ankle Straps on AmazonThe Bottom Line
If you do any sport involving sprinting, cutting, or explosive lower-body movements, the Nordic hamstring curl is likely the highest-ROI injury prevention exercise you can add. The evidence is unusually strong — 51% injury reduction across nearly 10,000 athletes. The barrier to entry is low (you need something to hold your ankles), but the DOMS from the first session is legendary.
Start low volume in the pre-season, progress systematically, and maintain 1x/week through the season. Your hamstrings — and your seasons — will be better for it.