Hydrotherapy for Arthritis: Benefits of Pool-Based Exercise

Key Takeaways

• Water exercise reduces joint stress while building strength and flexibility
• Research strongly supports hydrotherapy for knee and hip osteoarthritis
• Warm water (84-92°F) provides additional pain relief and muscle relaxation
• Buoyancy supports body weight, making movement easier and less painful
• Can be done independently or with a physical therapist
• Excellent option for people who can’t tolerate land-based exercise

For people with arthritis, water can be transformative. The same activities that cause pain on land become manageable—even enjoyable—in a pool. Hydrotherapy combines the benefits of exercise with the unique properties of water to help reduce pain and improve function.

Why Water Works for Arthritis

Buoyancy Reduces Joint Stress

In water:

• Chest-deep water reduces weight on joints by ~75%
• Waist-deep water reduces weight by ~50%
• Less stress means less pain during movement
• Allows exercises impossible on land

Resistance Builds Strength

Water provides:

• Natural resistance in all directions
• Resistance that increases with speed of movement
• Strength training without weights
• Safer resistance than gravity-based exercise

Warmth Relaxes and Relieves Pain

Warm water therapy:

• Relaxes muscles
• Increases circulation
• Reduces pain perception
• Allows greater range of motion
• Feels good, encouraging participation

Hydrostatic Pressure Reduces Swelling

Water pressure:

• Compresses tissues gently and uniformly
• May reduce joint swelling
• Supports circulation
• Provides sensory feedback

What Research Shows

Strong Evidence for Arthritis

For knee osteoarthritis:

• Cochrane review confirms small to moderate benefits
• Reduces pain and improves function
• Comparable to land-based exercise for some outcomes
• Better tolerated by many patients

For hip osteoarthritis:

• Positive results in multiple studies
• Improves pain, stiffness, and function
• Good option when land exercise is too painful

For rheumatoid arthritis:

• May reduce disease activity
• Improves function and well-being
• Safe during stable disease

How It Compares to Land Exercise

Advantages of water:

• Better tolerated by those with severe pain
• Allows movement impossible on land
• Lower injury risk
• More enjoyable for many

Similar outcomes:

• Both improve function over time
• Strength gains possible with both
• Both require consistency

Land advantages:

• More accessible (don’t need pool)
• Better bone-loading for osteoporosis
• Easier to progress resistance

Types of Hydrotherapy

Aquatic Physical Therapy

What it is:

• One-on-one therapy with licensed PT
• Individualized exercises for your condition
• Often covered by insurance
• Typically warm therapy pool

Best for:

• Post-surgical rehabilitation
• Severe arthritis limiting land exercise
• Learning proper techniques
• Specific treatment goals

Group Water Aerobics

What it is:

• Instructor-led group classes
• General fitness focus
• Usually at public pools or fitness centers
• Variety of levels available

Look for:

• Arthritis-specific classes
• Warm pool (84°F+)
• Qualified instructor
• Appropriate intensity level

Arthritis Foundation Programs

Aqua Flex:

• Designed specifically for arthritis
• Range of motion focus
• Gentle, appropriate exercises
• Trained instructors

Walk With Ease (water version):

• Walking program in pool
• Progressive structure
• Community support

Independent Pool Exercise

What it is:

• Self-directed exercise in any pool
• Following learned exercises or general guidelines
• Most accessible long-term option

Keys to success:

• Learn proper technique first
• Start conservatively
• Be consistent
• Progress gradually

Finding a Program

Where to Look

Therapy pools:

• Hospitals with rehabilitation departments
• Outpatient physical therapy clinics
• YMCA/YWCA facilities
• Arthritis Foundation partners

Public pools with programs:

• Community recreation centers
• Senior centers
• Fitness club chains
• University recreation facilities

What to Look For

Pool features:

• Warm water (84-92°F for arthritis)
• Easy entry (stairs, ramp, or lift)
• Appropriate depth (chest-deep for most exercises)
• Non-slip surfaces
• Accessible changing facilities

Program features:

• Instructor trained in arthritis exercise
• Appropriate pace and intensity
• Modified options for different abilities
• Welcoming atmosphere

Questions to Ask

1. What is the water temperature?
2. Is the instructor trained in arthritis exercise?
3. Can I observe a class before joining?
4. What ability levels are accommodated?
5. What if I need to rest during class?

Basic Pool Exercises

Getting Started

General guidelines:

• Start with 15-20 minutes
• Build to 30-45 minutes
• Exercise 2-3 times per week
• Use pool wall for balance as needed
• Stop if sharp pain occurs

Walking Exercises

Forward walking:

• Walk across pool at chest depth
• Arms swinging naturally
• Focus on normal gait pattern
• Vary speed for different challenge

Sideways walking:

• Step sideways across pool
• Keep toes pointed forward
• Works inner and outer thighs

Backward walking:

• Walk backward slowly
• Look over shoulder for safety
• Challenges balance and different muscles

Range of Motion

Leg swings:

• Hold pool wall
• Swing leg forward and back
• Swing leg side to side
• Control movement, don’t just let leg float

Arm circles:

• Arms out to sides at water level
• Make small circles, then larger
• Forward then backward

Knee lifts:

• March in place
• Lift knees toward surface
• Use arm swing for balance

Strengthening

Water walking lunges:

• Step forward into lunge position
• Return to standing
• Alternate legs
• Water provides resistance

Side leg lifts:

• Hold wall for support
• Lift leg to side against water resistance
• Control the return
• Works hip abductors

Arm movements:

• Push arms down against water
• Sweep arms across body
• Create figure-8 patterns
• Water provides resistance in all directions

Making the Most of Hydrotherapy

Optimize Your Session

Before:

• Use bathroom before entering
• Shower (pool hygiene)
• Remove jewelry
• Apply sunscreen if outdoor pool

During:

• Start with warm-up (walking, gentle movements)
• Progress to more challenging exercises
• Include cool-down
• Stay hydrated (yes, even in water)

After:

• Shower and dry thoroughly
• Rest if needed
• Note how you feel
• Apply moisturizer (chlorine dries skin)

Progression Tips

As you get stronger:

• Increase duration
• Add exercises
• Increase speed (water resistance increases)
• Move to shallower water (less support, more challenge)
• Use aquatic equipment (noodles, paddles)

Staying Consistent

Keys to adherence:

• Choose convenient location
• Find enjoyable class/time
• Make social connections
• Track your progress
• Notice improvements

Equipment and Accessories

Helpful Items

Water shoes:

• Protect feet
• Provide traction
• Reduce slipping risk

Pool noodles:

• Add resistance
• Assist with floating
• Support during exercises

Kickboards:

• Support for leg exercises
• Add challenge for arms

Water dumbbells:

• Increase arm resistance
• Various sizes available

Flotation belts:

• Support for deep water
• Allow vertical exercises
• Reduce joint loading further

Special Considerations

Safety Tips

General precautions:

• Stay in depth where you can stand
• Use handrails when available
• Don’t exercise alone (have buddy or lifeguard)
• Exit pool if dizzy or unwell
• Be aware of pool rules

Health considerations:

• Clear exercise with doctor if heart conditions
• Caution with low blood pressure (warm water dilates vessels)
• Watch for overexertion
• Know emergency procedures

For Specific Conditions

Severe arthritis:

• Start with deeper water (more support)
• Focus on gentle range of motion
• Progress very gradually
• Consider individual therapy first

Hip or knee replacement:

• Usually can resume pool exercise 6-8 weeks post-surgery
• Follow surgeon’s guidance
• Avoid certain movements initially
• Excellent for rehabilitation

Balance problems:

• Stay near wall
• Use flotation devices
• Consider individual instruction
• Water provides safe environment to challenge balance

Cost and Access

Typical Costs

Aquatic physical therapy:

• Covered by insurance (often)
• Copays vary
• Usually 1-2 sessions/week for 4-8 weeks

Community classes:

• $5-$15 per class
• Monthly passes: $30-$100
• Senior discounts common

Pool membership:

• $20-$80/month
• Provides unlimited access
• May include land facilities too

Insurance Coverage

• PT-directed aquatic therapy often covered
• Group fitness classes rarely covered
• Medicare may cover therapy pools
• Check your specific plan

Frequently Asked Questions

Do I need to know how to swim?

No. Most aquatic therapy and water aerobics occurs in shallow water where you can stand. Swimming ability isn’t required. If you’re uncomfortable in water, start with very shallow water and work with an instructor.

How warm should the pool be?

For arthritis exercise, 84-92°F (29-33°C) is ideal. Warmer water (around 92°F) is better for gentle range of motion; slightly cooler (84-88°F) is better for more vigorous exercise. Standard lap pools (78-82°F) may feel too cold for comfortable arthritis exercise.

Can I do water exercise if I have a joint replacement?

Usually yes, starting 6-8 weeks after surgery when incisions are healed. Aquatic exercise is excellent for rehabilitation. Always follow your surgeon’s specific guidance on timing and allowed activities.

Why does my pain feel better in the pool?

Several factors: warm water relaxes muscles and increases pain threshold, buoyancy reduces joint loading, hydrostatic pressure may reduce swelling, and movement becomes easier and more pleasant. The combination provides significant pain relief for many people.

How often should I do water exercise?

For arthritis management, 2-3 times per week is typical. Some people do daily gentle sessions. Listen to your body—water exercise should leave you feeling better, not exhausted or in more pain.

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Exploring exercise options? Read about water aerobics programs or learn about chair exercises for limited mobility.

Last medically reviewed: February 2025

Medical Disclaimer: This article is for informational purposes only. Discuss any new exercise program with your healthcare provider, especially if you have heart conditions, balance problems, or recently had surgery.