What exercises can activate the soleus muscle in a patient?

Exercises to Activate the Soleus Muscle

The most effective exercises to activate the soleus muscle are seated calf raises (bent-knee plantar flexion), standing on toes, and plantar flexion combined with knee extension, as these positions selectively recruit the soleus over the gastrocnemius.

Primary Soleus-Specific Exercises

Seated Calf Raises (Bent-Knee Position)

• Seated calf press/heel raise with knees bent is the gold standard for soleus isolation because the bent knee position reduces gastrocnemius contribution while maximally activating the soleus 1, 2
• Perform 4 sets of 15 repetitions at approximately 70% of one-repetition maximum (15RM) 3
• The bent-knee position is critical—when the knee is flexed, the biarticular gastrocnemius is mechanically disadvantaged, forcing greater soleus recruitment 2

Standing on Toes

• Standing on toes produces maximal facilitation of soleus muscle activation, with 100% consistent motor responses compared to only 61% at rest 4
• This position shortens central motor conduction time by an average of 5.2 msec, indicating optimal neuromuscular recruitment 4
• Toe-standing shows a soleus-to-gastrocnemius EMG ratio of 1.16, demonstrating preferential soleus activation 5

Combined Plantar Flexion with Knee Extension

• Adding knee extensor activity during plantar flexion selectively increases soleus activation while simultaneously depressing gastrocnemius activity 2
• This occurs because the gastrocnemius acts as a knee flexor (antagonist during knee extension), while the monoarticular soleus has no knee function 2
• Perform isometric plantar flexion at 10-30% maximum effort while simultaneously performing knee extension at 50-100% maximum effort 2

Exercise Prescription Parameters

Frequency and Volume

• Train 2-3 days per week with at least 48 hours rest between sessions targeting the same muscle group 6
• Complete 2-4 sets per exercise for optimal strength gains 6
• Allow 2-3 minutes rest between sets 6

Intensity Progression

• Start at 60-70% of 1RM for 8-12 repetitions if you are novice to intermediate 6
• Progress to ≥80% of 1RM for experienced exercisers using Heavy Slow Resistance training protocols 6
• Gradually increase resistance, repetitions, or frequency as strength improves 6

Important Caveat About Soleus Response

• The soleus demonstrates a relatively poor protein synthesis response to resistance exercise (approximately 0.019% per hour increase) compared to other muscles like the vastus lateralis (0.045-0.060% per hour) 3
• Despite using comparable glycogen (36-54 mmol/kg wet weight), the soleus shows only about half the anabolic response of thigh muscles 3
• This explains why calf muscles are generally less responsive to resistance training and require consistent, long-term programming 3

Task-Specific Activation Patterns

Low-Intensity Activities (Standing)

• During simple standing on one leg, the soleus-to-gastrocnemius EMG ratio is 1.67, showing soleus dominance 5
• The soleus is preferentially recruited for postural control and sustained low-force activities 5

High-Intensity Activities (Hopping/Jumping)

• As force and speed demands increase (maximal hopping), there is a shift toward gastrocnemius recruitment, with the soleus-to-gastrocnemius ratio dropping to 0.81 5
• For maximal soleus activation, focus on sustained, moderate-intensity exercises rather than explosive movements 5

Complementary Interventions

Stretching Protocol

• Perform soleus-specific stretches with bent knees for 30 seconds with 3 repetitions 7
• Adding dedicated soleus stretches to regular protocols improves ankle flexibility, maximum plantarflexion strength, and functional performance beyond gastrocnemius stretching alone 7
• Soleus stretching is often neglected but is critical for push-off mechanics in speed movements 7

Warm-Up Considerations

• Begin with 5-10 minutes of low-intensity repetitive range-of-motion exercises before strength training 1
• Warm muscles are more responsive to both strengthening and stretching interventions 6

Special Populations and Modifications

For Patients with Joint Issues

• Aquatic exercises in warm water (86°F) provide buoyancy to reduce joint loading while allowing resistance training 1, 8
• Pool therapy is particularly useful for patients who cannot tolerate land-based loading 1

For Deconditioned Patients

• Start with very light intensity (40-50% of capacity) and progress gradually as tolerated 8
• Use pain response as a guide to appropriate exercise intensity and duration 8
• Consider isometric exercises that don't require significant movement if dynamic exercises are not tolerated 8