Move with control
Mobility vs flexibility: what is the difference?
Flexibility is how far a joint can be moved, often with help from gravity, a partner or a strap. Mobility is how much of that range you can reach and control on your own. For training and daily life, mobility matters more, because you need to be strong in the positions you use.
By Dai Manuel (Coach Moose) · Last reviewed
How can I test myself?
Active versus passive knee-to-chest
Draft, awaiting coach confirmation.
Lie on your back. Pull one knee toward your chest with your hands and note how far it comes. Then let go and lift the same knee as far as you can using only your hip.
Pass standard: Draft standard for coach confirmation: your active range comes close to your passive range. A big gap suggests strength at end range is the limit, not flexibility.
Which movements can it limit?
Flexible but unstable
Some people reach big ranges passively but cannot hold them. In an overhead press or a wall ball, that shows up as a position that collapses under load. Their work is strength at end range, not more stretching.
Strong but stiff
Others are strong in a short range. A front squat or deadlift stalls when the range runs out. Full-range lifting and slow controlled drills help open it up.
HYROX stations
Wall balls ask for a deep squat and an overhead finish at once, and the sled push asks for ankle and hip range. Usable range, not passive stretch, is what carries through a race.
These are coaching applications of movement demands, not validated HYROX performance predictions. The studies below examine general mobility and resistance training.
How can I work on it?
End-range strength
Active straight leg raise
Lie on your back and lift one straight leg as high as you can without help, then lower slowly.
- Regression
- Bend the bottom knee.
- Progression
- Add a three-second hold at the top.
- Sets and reps
- 2 sets of 6 reps per side.
- Frequency
- Three days a week.
Loaded position
Full-range goblet squat
Squat as deep as you can control with a light kettlebell, pausing at the bottom.
- Regression
- Squat to a box.
- Progression
- Lengthen the pause.
- Sets and reps
- 2 sets of 8 reps.
- Frequency
- Twice a week.
Passive range
Strap-assisted hamstring stretch
Lie on your back with a strap around one foot and gently bring the leg up, then compare it with your active raise.
- Regression
- Keep a soft knee.
- Progression
- Hold for three slow breaths, then retest the active lift.
- Sets and reps
- 2 holds of 30 seconds per side.
- Frequency
- After training.
When should I retest?
Retest every deload week, using the same setup. Look for a more comfortable position, steadier control and changes in measured range. Compare like with like, not a warmed-up attempt with a cold one.
When should I see a physio?
Stop if a test or drill causes pain. Pain, numbness, or no change after six weeks is a reason to see a physio. This screen is not a diagnosis.
What would Coach Moose say?
I have nothing against stretching. It just does not finish the job. The range you own is the range you can use under load.
What else should I know?
Should I still stretch?
If you enjoy it, yes. Research shows strength training through full range can improve range of motion about as well as stretching, so combine both if you like.
Does stretching before training hurt performance?
Long static holds just before explosive work may reduce performance slightly. Short holds inside a dynamic warm-up are generally fine.
How do I know if I have a mobility problem?
Try the Range Screen. It checks the positions most training uses and tells you where to start.
When should I see a physio?
Stop at pain. Pain, numbness or no change after six weeks is a reason to see a physio for individual assessment.
What does the research say?
- Afonso et al. (2021). Strength training versus stretching for improving range of motion: a systematic review and meta-analysis.
- Behm, Blazevich, Kay and McHugh (2016). Acute effects of muscle stretching on physical performance, range of motion, and injury incidence in healthy active individuals: a systematic review.
- Skopal, Drinkwater and Behm (2024). Application of mobility training methods in sporting populations: a systematic review of performance adaptations.