Hydrotherapy vs Physical Therapy: Key Differences, Benefits & Which Is Right for You

Key Takeaways

Hydrotherapy and land-based physical therapy are not competing treatments — they are different tools, and the research shows each has distinct strengths depending on your condition and goals.

A 2007 randomized clinical trial found that hydrotherapy produced greater pain relief for knee osteoarthritis than conventional land-based exercise, with patients reporting better function and quality of life [1].

A 2023 meta-analysis of 32 randomized controlled trials confirmed that aquatic exercise significantly reduces pain and improves function for chronic musculoskeletal conditions, performing comparably to land-based exercise in most outcome measures [2].

Traditional physical therapy is generally superior for targeted muscle strengthening, sport-specific rehabilitation, and progressive loading protocols.

Combining both approaches — water-based and land-based therapy — often produces better outcomes than either one alone.

If you have been dealing with chronic pain, recovering from surgery, or trying to manage a joint condition, you have probably been told to “try physical therapy.” Fair enough. But then someone mentions hydrotherapy, and suddenly you are wondering: which one actually works better?

The honest answer is that it depends. These two approaches overlap more than most people realize, and the research tells a more interesting story than “one is better than the other.” In many cases, the smartest move is not choosing between them at all.

Let’s look at what the evidence actually says.

What Is Hydrotherapy?

Hydrotherapy is therapeutic treatment that uses water — its temperature, buoyancy, and hydrostatic pressure — to reduce pain, improve mobility, and support recovery. It includes everything from structured aquatic exercise programs in heated pools to cold water immersion, contrast therapy, and whirlpool treatments.

When people talk about hydrotherapy in a rehabilitation context, they usually mean aquatic exercise therapy: guided movement in a warm pool (typically 33-36 degrees Celsius), supervised by a physiotherapist. The warm water reduces your effective body weight by 60-80%, takes load off your joints, and allows you to move in ways that would be painful or impossible on dry ground.

For a full breakdown of how hydrotherapy works and the different types available, see our complete guide on what hydrotherapy is and how it works.

What Is Physical Therapy?

Physical therapy — also called physiotherapy — is a broad clinical discipline focused on restoring movement, function, and strength through exercise, manual techniques, and education. Physical therapists treat everything from sports injuries and post-surgical recovery to chronic pain, neurological conditions, and balance problems.

Land-based physical therapy typically involves targeted strengthening exercises, stretching, manual therapy (hands-on joint and soft tissue work), gait training, and progressive loading protocols. It is the default rehabilitation approach in most healthcare settings, and for good reason — the evidence base is enormous.

Here is the thing most people miss: hydrotherapy is not a separate discipline from physical therapy. It is a tool within physical therapy. Many licensed physical therapists use aquatic environments as part of their treatment plans. The real question is not “hydrotherapy or physical therapy” but rather “water-based or land-based therapy — and when does each make more sense?”

Head-to-Head: What the Research Shows

Several well-designed studies have directly compared aquatic exercise to land-based exercise for the same conditions. The results are more nuanced than you might expect.

A landmark 2007 randomized clinical trial by Hinman and colleagues assigned 71 adults with hip or knee osteoarthritis to either a hydrotherapy program or a conventional land-based exercise program. Both groups exercised for six weeks. The hydrotherapy group showed significantly greater improvements in pain and physical function compared to the land-based group. Participants in the water also reported better quality of life scores [1].

That same year, Hall and colleagues ran a separate trial comparing hydrotherapy classes to Tai Chi classes for people with osteoarthritis. Both groups improved, but the hydrotherapy group showed notable improvements in physical function and pain management, reinforcing the idea that warm-water exercise provides meaningful clinical benefits for joint conditions [5].

A more recent 2024 meta-analysis pooled data from multiple randomized controlled trials examining hydrotherapy for knee osteoarthritis specifically. The analysis found that hydrotherapy significantly reduced pain and improved joint function compared to control groups, with a favourable safety profile. Adverse events were rare and mild [3].

The large-scale 2023 systematic review in the Journal of Orthopaedic Surgery and Research — covering 32 RCTs and over 2,200 participants with various chronic musculoskeletal disorders — found that aquatic exercise was as effective as land-based exercise for most outcome measures, including pain reduction and functional improvement. Where aquatic exercise had a clear edge was in adherence: people stuck with it longer because it hurt less during sessions [2].

And a 2017 trial by Tomas-Carus and colleagues focused on older women with knee osteoarthritis found that an 18-week hydrotherapy program significantly improved pain, physical function, and quality of life. These improvements were clinically meaningful — not just statistically detectable — and participants maintained gains even after the structured program ended [4].

The pattern across these studies is consistent: for joint conditions and chronic pain, hydrotherapy performs at least as well as land-based exercise and often outperforms it on pain relief and patient adherence.

When Hydrotherapy Has the Edge

The research points to several scenarios where water-based therapy has clear advantages over land-based approaches.

Joint Conditions and Arthritis

This is where hydrotherapy shines brightest. The combination of buoyancy (reducing joint load by up to 80%), warm water (relaxing muscles and dampening pain signals), and hydrostatic pressure (reducing swelling) creates an environment that is uniquely suited to people with painful, stiff, or inflamed joints. Multiple meta-analyses confirm superior pain outcomes for hydrotherapy in osteoarthritis compared to land-based exercise alone [1][3][4].

For more on this, see our article on the benefits of hydrotherapy for joint pain.

Chronic Pain and Limited Mobility

People with conditions like fibromyalgia, chronic lower back pain, or widespread musculoskeletal pain often cannot tolerate land-based exercise at the intensity needed to see improvements. The weight-bearing demands are simply too much. In the pool, those same people can exercise for 30-45 minutes with manageable discomfort because the water is carrying most of their body weight.

This is not a small distinction. If a treatment only works when you can actually do it consistently, the one that causes less pain during the process has a real clinical advantage. The 2023 meta-analysis specifically noted higher adherence rates in aquatic exercise groups compared to land-based groups [2].

Our guide on how hydrotherapy helps manage chronic pain and inflammation covers this in detail.

Early Post-Surgical Rehabilitation

After joint replacements, ACL reconstructions, or spinal procedures, the surgical site is healing and the surrounding muscles are weak. Full weight-bearing exercise is painful and potentially risky in the early stages. Pool-based rehabilitation allows patients to begin range-of-motion exercises and gentle strengthening weeks before they could safely do the same work on land.

Most orthopedic surgeons now include aquatic therapy as part of their post-surgical rehabilitation protocols, particularly for lower extremity procedures.

Older Adults and Fall Risk

Water provides a built-in safety net. If you lose your balance in a pool, the water catches you. For older adults with osteoporosis, balance issues, or fear of falling, this makes aquatic exercise a safer and more confidence-building option than land-based programs. The social component of group pool classes is a bonus — isolation is a significant health risk for older adults, and regular classes address it.

When Traditional Physical Therapy Is Better

Being honest about limitations is important. There are scenarios where land-based physical therapy is clearly the better choice.

Targeted Muscle Strengthening

If your goal is building specific muscle strength — say, rehabilitating a weak quadriceps after a knee injury or strengthening your rotator cuff after shoulder surgery — land-based exercise with progressive resistance (weights, bands, machines) is more effective. Water provides resistance, but it is constant and omnidirectional. You cannot isolate individual muscles the same way you can with targeted land-based exercises, and you cannot incrementally increase load with the precision that progressive overload requires.

Sport-Specific Rehabilitation

Athletes returning from injury need to train the exact movements they will perform in their sport. A soccer player needs to sprint, cut, and kick. A basketball player needs to jump and land. These sport-specific demands can only be trained on land, on the surfaces where the sport is played. Pool work is excellent for maintaining cardiovascular fitness and general mobility during the early recovery phase, but the final stages of rehabilitation must happen on dry ground.

Convenience and Accessibility

This is a practical consideration, but it matters. You can do land-based physical therapy exercises almost anywhere — at a clinic, at a gym, or in your living room with minimal equipment. Hydrotherapy requires a pool, and not just any pool: therapeutic aquatic exercise works best in a warm-water pool (33-36 degrees Celsius), which is warmer than most public swimming pools.

Not everyone has access to an appropriate facility, and scheduling pool time adds logistical friction that land-based exercise avoids. Cost can also be a factor — aquatic therapy sessions sometimes cost more than standard physiotherapy visits.

Manual Therapy and Hands-On Techniques

Certain physical therapy interventions — joint mobilisation, soft tissue massage, dry needling, taping — require direct hands-on contact that cannot be performed in water. If your treatment plan depends heavily on manual techniques, land-based sessions are necessary.

Can You Combine Them?

Yes — and this is often the best approach.

Many rehabilitation programs use aquatic therapy in the early stages, when pain and swelling are high and weight-bearing tolerance is low, then transition patients to land-based exercises as they progress. You get the pain-reduction and mobility benefits of water first, then build on that foundation with targeted strengthening and sport-specific training on land.

Some clinics run hybrid programs where patients alternate between pool and gym sessions within the same week. Research supports this approach — the combination addresses a wider range of rehabilitation goals than either modality alone.

The science behind this is straightforward. Warm water gets you moving when you otherwise could not. Land-based exercise builds on that movement to restore real-world strength and function. One opens the door; the other walks you through it.

For a deeper understanding of the physiological mechanisms at play, check out our article on the science behind hydrotherapy and how it promotes healing.

How to Decide Which Is Right for You

If you are trying to figure out which approach makes sense for your situation, here is a simple decision framework.

Start with hydrotherapy if:

You have significant joint pain, swelling, or stiffness
Weight-bearing exercise is painful or impossible right now
You are in the early stages of post-surgical recovery
You have a chronic condition like fibromyalgia or widespread musculoskeletal pain
You are an older adult with balance concerns or fear of falling

Start with land-based physical therapy if:

You need to build specific muscle strength
You are in the later stages of recovery and need sport-specific training
You do not have access to a suitable warm-water pool
Your treatment requires hands-on manual therapy techniques
You need maximal convenience and minimal scheduling friction

Combine both if:

You can access both options
You are recovering from a major joint surgery
You have chronic pain but also need to build functional strength
Your physical therapist recommends a phased approach

Talk to your physical therapist or doctor about which combination makes sense for your specific diagnosis and goals. The best program is the one you will actually follow through on — and for many people, that means starting in the water where movement is less painful, then progressing to land.

Comparison Table: Hydrotherapy vs. Land-Based Physical Therapy

Factor	Hydrotherapy (Aquatic)	Land-Based Physical Therapy
Pain relief	Strong — warm water and buoyancy reduce pain during and after exercise. Superior for joint pain [1][3].	Good — but weight-bearing can aggravate sensitive joints during early recovery.
Joint mobility	Excellent — buoyancy allows greater range of motion with less pain.	Good — but limited by pain tolerance in early stages.
Strength building	Moderate — water resistance helps, but cannot match progressive loading with weights.	Excellent — targeted, measurable, and progressive.
Accessibility	Limited — requires warm-water pool, scheduling, transportation.	High — can be done at a clinic, gym, or home.
Cost	Moderate to high — aquatic sessions often cost more.	Moderate — standard rates; home exercises are free.
Best for	Arthritis, chronic pain, early post-surgical rehab, older adults, limited mobility.	Targeted strengthening, sport-specific rehab, later-stage recovery, manual therapy needs.

FAQ

Is hydrotherapy a type of physical therapy?

Yes, technically. Hydrotherapy — specifically aquatic exercise therapy — is a modality used within physical therapy. It is administered by licensed physical therapists or physiotherapists in a water-based setting. Think of it as one approach within the broader toolbox of physical therapy, not a separate discipline.

Can hydrotherapy replace land-based physical therapy entirely?

For most people, no. Hydrotherapy is excellent for pain relief, early mobilisation, and improving mobility, but it cannot fully replicate the targeted strengthening and sport-specific training that land-based therapy provides. The most effective rehabilitation programs typically combine both. That said, for some older adults or people with severe chronic pain, aquatic exercise alone may be the most realistic long-term maintenance program.

Is one more evidence-based than the other?

Both are well-supported by research. Land-based physical therapy has a larger overall evidence base simply because it has been studied more broadly and for more conditions. Hydrotherapy has strong evidence specifically for osteoarthritis, chronic musculoskeletal pain, and post-surgical rehabilitation. Neither approach lacks scientific support — the question is which fits your specific situation. For more on the science, see our article on the benefits of hydrotherapy explained.

Does insurance cover hydrotherapy?

It depends on your country and plan. In many healthcare systems, aquatic therapy prescribed by a doctor for a diagnosed condition — such as osteoarthritis or post-surgical rehabilitation — is covered the same way standard physiotherapy is covered. Spa-style hydrotherapy or self-directed pool use typically is not. Check with your insurer and ask your doctor for a referral if coverage matters to you.

How long before I see results from either approach?

Most clinical studies show meaningful improvements within 6-12 weeks of consistent therapy, regardless of whether it is aquatic or land-based. The 2017 Tomas-Carus trial saw significant improvements after 18 weeks [4], while the 2007 Hinman trial found differences as early as 6 weeks [1]. Consistency matters more than the specific modality. Two or three sessions per week over several months is the pattern that produces the best outcomes in the research.

Sources

[1] Hinman, R. S., Heywood, S. E., & Day, A. R. (2007). Aquatic physical therapy for hip and knee osteoarthritis: Results of a single-blind randomized controlled trial. Physical Therapy, 87(1), 32-43. https://pubmed.ncbi.nlm.nih.gov/17986497/

[2] Journal of Orthopaedic Surgery and Research (2023). Efficacy of aquatic exercise in chronic musculoskeletal disorders: A systematic review and meta-analysis of 32 randomized controlled trials. https://josr-online.biomedcentral.com/articles/10.1186/s13018-023-04417-w

[3] PMC (2024). The efficacy and safety of hydrotherapy in patients with knee osteoarthritis: A meta-analysis of randomized controlled trials. https://pmc.ncbi.nlm.nih.gov/articles/PMC10942168/

[4] Tomas-Carus, P., et al. (2017). Hydrotherapy improves pain and function in older women with knee osteoarthritis: A randomized controlled trial. https://pmc.ncbi.nlm.nih.gov/articles/PMC5693429/

[5] Hall, J., et al. (2007). Physical activity for osteoarthritis management: A randomized controlled clinical trial evaluating hydrotherapy or Tai Chi classes. Arthritis & Rheumatism, 57(3), 407-414. https://pubmed.ncbi.nlm.nih.gov/17443749/

Hydrotherapy vs. Physical Therapy: What the Research Says

What Is Hydrotherapy?

What Is Physical Therapy?

Head-to-Head: What the Research Shows