Exercise approach

Short entry

[Verified]

Full entry coming in 2027

Encyclopedia definition

Aquatic (underwater) treadmill training: walking or running on a motorized treadmill belt in a water-filled tank or pool, where water depth sets how much body weight is unloaded and belt speed (and, on some units, water jets) sets the workload; it is used for gait training, conditioning, exercise testing and rehabilitation in people, and in veterinary rehabilitation.

Evidence label: [Verified] that the statements below match the cited studies and reviews, read on October 19, 2026.^1–12 Most human studies are small, single-session or uncontrolled. Reporting advice is this entry’s own recommendation [Proposed]. Numbers refer to the reference list below.

Credit and origin: The aquatic treadmill is a type of equipment, not a technique with a founder. A 2025 scoping review searched the literature on underwater treadmill exercise from 1947 to 2024.¹ [Verified]

Also called: Underwater treadmill (UWTM)^1,2; aquatic treadmill (AT, ATM)^3,4; aquatic treadmill training (ATT)⁵; underwater gait training⁶; hydrotreadmill; water treadmill

Scope note: this entry covers walking and running on a treadmill in water. The general effect of water depth on load is in Unloading and immersion depth; walking in a pool without a treadmill will be covered in Aquatic gait training and water walking (coming soon).

Usage note: papers use underwater treadmill and aquatic treadmill for the same equipment.^1,3 The Evidence Library also includes veterinary studies in dogs,² so check the population before applying a result. Report water depth by body landmark, belt speed, jet setting and water temperature. [Proposed]

Cite this entry

How to cite

Salzman, A. (Ed.). (2026). Aquatic (underwater) treadmill training. In Aquatic Therapy Encyclopedia™. ATU Educational Services, LLC; published by the Aquatic Therapy Foundation. https://aquatictherapyfoundation.org/encyclopedia/underwater-treadmill/

Permissions: You may quote and cite this entry with attribution. Reproducing or adapting full entries requires written permission from ATU Educational Services, LLC. Quoted material, trademarks and linked documents belong to their respective owners and are not covered by this permission.

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Longer definition

• Settings that change the load. In a test protocol for healthy men, the water was set at each person’s navel (umbilicus) level at 28–29 °C, and speed rose from 0.7 km/h by 0.6–0.7 km/h every 2 minutes.⁷ Another program used a set belt speed with front water jets increased from 80% to 95% over 8 weeks.⁸ See Unloading and immersion depth. [Verified]
• Exercise testing. A 12-stage aquatic treadmill test in 14 healthy men produced steady increases in heart rate, oxygen uptake and rating of perceived exertion (RPE), and was proposed for patients who have difficulty walking on a land treadmill.⁷ A systematic review reported peak oxygen uptake of 28.6–62.2 mL/kg/min across underwater treadmill and cycling tests.⁹ [Verified]
• Chronic pain and osteoarthritis. A 2025 scoping review found nine clinical trials in adults with chronic pain, all in osteoarthritis; they reported improvements in pain, balance, mobility, strength and quality of life, but larger randomized trials in other pain conditions are needed.¹ [Verified]
• Stroke. In 21 people with subacute stroke, 15 sessions of aquatic treadmill training improved comfortable walking speed, Berg Balance Scale and balance confidence; there was no control group.⁵ In a 2025 feasibility study, 6 stroke survivors completed 97% of sessions over 4 weeks; brain blood-flow responsiveness rose on average but not significantly.⁴ [Verified]
• Children with cerebral palsy. In single-session crossover studies with 8 children with cerebral palsy and 15 typically developing children, walking on an aquatic treadmill made pelvic and leg joint motion more regular than a dry treadmill,^3,6 and increased the complexity of muscle control in the more affected leg.¹⁰ In typically developing children, knee flexion during aquatic treadmill walking was 34° lower than overground.¹¹ The authors call for longer-term studies.^3,10 [Verified]
• High-intensity work. An 8-week Tabata-style sprint program on an underwater treadmill improved flexibility and anaerobic power in 25 adults.⁸ See Aquatic HIIT. [Verified]
• Veterinary use. In a 2026 pilot study in dogs after hip surgery, 10 weekly underwater treadmill sessions were followed by reduced lameness and increased weight bearing on the operated leg.² [Verified]
• Other ways to unload walking. In a 2026 pilot trial in knee osteoarthritis, treadmill walking with lower-body positive pressure improved pain, while walking in a pool (not on a treadmill) did not change pain significantly over 8 weeks.¹² [Verified]

The evidence label after each statement shows how well it is sourced; it is not a grade of clinical effectiveness.

Search the Hot List™

The Evidence Library (our Hot List) is the searchable list of published studies and reviews on aquatic therapy.

The search also returns land treadmill tests and veterinary studies; open “More details” to check the population and setting. The 2013, 2017 and 2022 studies are older than the Hot List.

Resource links

Professional and research pages. More links will be added as this entry is developed.

• A scoping review of underwater treadmill exercise in clinical trials of chronic pain (2025)
• Cardiopulmonary exercise test protocol using an aquatic treadmill (open access, 2022)

References

Reference numbers match the evidence labels above.

Related entries

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