In 40 seconds
Hyrox's sled push station produces some of the highest knee loading in athletic training — particularly for taller athletes whose stride bends the knee deeper under heavy load. Patellofemoral irritation is common. PEMF therapy reduces patellar inflammation and supports cartilage health. Combined with quad/glute strengthening, it lets you keep training through a Hyrox prep block.
Quick facts
- Hyrox station: Sled push (~50m) and sled pull
- Common knee issue: Patellofemoral pain (runner's knee variant)
- PEMF role: Reduces inflammation, supports cartilage
- Pairs with: Quad and glute strengthening, technique work
- Realistic: Don't push through severe pain
Why this injury happens in this sport
The sled push loads the knee at deep flexion under heavy resistance. Repeated training with poor mechanics or insufficient quad strength irritates the patella.
Recovery and return to sport
Reduce sled volume by 30–50% during a flare. PEMF 2–3× per week. Quad strengthening (split squats, leg press, goblet squats) and glute work build the resilience needed for full Hyrox training.
Contraindications
Hard exclusions — do not have PEMF if any apply:
- Pacemaker, implantable cardioverter-defibrillator (ICD), or any cardiac electronic device
- Cochlear implant or other implanted electronic hearing device
- Spinal cord stimulator, deep-brain stimulator, vagus nerve stimulator
- Intrathecal pump or implanted drug pump
- Insulin pump (continuous glucose monitors are usually fine — confirm with the clinic)
- Active infection at the treatment site
- Pregnancy — when treatment would be over the abdomen, lumbar spine, or pelvis
Discuss with your GP or specialist before booking if any apply:
- Active malignancy or recent cancer history (oncologist clearance required)
- History of seizures or epilepsy
- Multiple sclerosis or other neurological condition under specialist care
- Anticoagulant therapy (PEMF itself does not thin blood, but bruising risk if local circulation is already compromised)
- Children under 14 (most UK clinics will not treat under-18s without paediatric specialist input)
- Recent surgery within the last 14 days at the treatment site (confirm with surgeon)
NOT contraindications — these are commonly misunderstood:
- Plates, rods, screws and other passive metal orthopaedic hardware
- Dental implants and dental crowns
- Joint replacements (hip, knee, shoulder)
- IUDs (copper or hormonal)
- Tattoos and piercings (jewellery should be removed for the session)
Specific to this condition: pacemakers, defibrillators, cochlear implants, insulin pumps, electronic implants; active malignancy without specialist clearance; pregnancy (over the abdomen); active infection; epilepsy without GP clearance.
Frequently asked questions
Is Hyrox bad for my knees?
Not inherently — but volume and technique matter. Most knee issues are over-volume + under-strength.
Should I lose weight on the sled?
Reduce weight during recovery, not technique. Light heavy reps with good positions > heavy reps with broken positions.
Looking for a PEMF clinic near you?
We list every credible PEMF therapy provider in the UK so you can find one near home.