01/25/2026
Images outlining anticipated mechanical changes with anti-gravity treadmills.
Anti-gravity treadmills (Alter-G, body-weight support running) are often marketed as a faster way back from injury.
They can be useful, but they’re not essential. When misused, they leave runners under-prepared for real running.
What They Do Well:
🔹Reduce ground reaction forces
🔹Lower metabolic cost at a given speed
This may help preserve confidence and maintain some aerobic stimulus.
Nice? Yes. Necessary? No. What Often Gets Missed:
As body weight support increases, running mechanics change.
Research consistently shows:
🔹Cadence decreases as body weight is reduced
🔹Stride length + flight time increase
🔹 Ankle and knee ROM decrease
🔹 Vertical stiffness drops
🔹 Forefoot loading remains high, even at high unloading levels
In other words: You’re still stressing tissue, but in a different way.
The Cadence Problem: Step rate naturally drops about 1.5–3.5% for every 10% of body weight removed.
That matters because: Lower cadence = higher joint loading per step. This lower Cadence can negate impact-reduction benefits
Anti-gravity treadmills are:
✔️ A tool, not a shortcut
✔️ Sometimes helpful early
❌ Not required for a successful return to running
❌ Not something that gets you back faster
If misused:
❌ You'll lose tolerance to real-world loading & be underprepared when running unassisted.
A bike, incline walking, or carefully dosed ground running often accomplishes the same goal - without altering mechanics.
*If you choose to use one of these devices, keep in mind:
⚡~20% body-weight support: Reduced forces with minimal gait disruption
⚡≥40% support: Clear, consistent biomechanical alterations
If the goal is cardiovascular preservation, cross-training works with less downside.
Photo's taken from:
Stockland 2019: The Effect of Anti-Gravity Treadmill on Running Cadence
Vincent 2022: Role of Antigravity Training in Rehab & R2Sport After Running Injuries
