Your calf muscles are often called the body’s “second heart.” Not because they replace the heart, but because they play an important role in helping move blood from the lower legs back toward the chest.
Nick Tumminello is known as the "Trainer of Trainers." He has been a trainer for over 20 years working NFL and MMA athletes, bodybuilders and fitness enthusiasts. Nick is the 2016 NSCA Personal Trainer of the Year, the editor-in-chief of the NSCA’s PTQ journal, and he has authored four books, including the best-selling Strength Training for Fat Loss.
Every step you take creates a natural pumping action.
When the calf muscles contract during walking, they compress the deep veins in the lower leg and help push blood upward against gravity. This mechanism is commonly called the calf muscle pump (CMP). Reduced calf pump function has been associated with blood pooling, swelling, chronic venous insufficiency (CVI) and venous ulcer risk.
For trainers, this matters because proper calf training and ankle mobility may have more importance for circulation and lower-body health than many people realize.
(Watch this video to see Nick's favorite calf + ankle dorsiflexion mobility exercises.)
Why Ankle Mobility Matters
Research has shown that reduced ankle mobility — particularly limited dorsiflexion — is associated with poorer calf pump function and altered venous hemodynamics.
In simple terms, less ankle motion can mean:
• Reduced efficiency of the calf muscle pump (“second heart”)• Poorer venous return from the lower legs• Greater blood pooling after movement• Increased circulatory concerns in people already dealing with venous disease
This doesn’t mean: “Tight calves automatically equal poor circulation.”
Nor does it mean: “Everyone with limited dorsiflexion has a vascular problem.”
But it does suggest that maintaining ankle mobility and calf function has value beyond squatting depth, increased knee injury risk and athletic performance.
The Walking Connection
Normal walking creates repeated cycles of:
1. Ankle motion2. Calf contraction3. Venous compression4. Blood return toward the heart
This is one reason walking is often recommended in populations with venous insufficiency because regular movement repeatedly activates the calf muscle pump and may improve venous return.
The more you move, the more opportunities the calf pump has to do its job.
This also explains why: Long periods of sitting, inactivity, travel, and immobilization tend to increase circulatory concerns.
Movement is medicine here.
Practical Takeaways for Trainers
If you work with active adults, older clients or people who sit most of the day:
1. Don’t ignore ankle mobility
You don’t need everyone chasing extreme dorsiflexion. But restoring usable ankle motion may help movement efficiency and support calf pump function.
2. Train the calves
• Calf raises.• Sled pushes• Incline walking.• Leaning wall call raises
Strong calves are not only an aesthetic muscle. They’re part of the body’s circulation assist system.
3. Keep clients moving
• Frequent walking breaks.• Movement snacks.• Foot and ankle mobility drills.• Short bouts throughout the day.
Sometimes the best intervention is simply less sitting and more movement.
The Big Picture
The calves aren’t literally a second heart, but they do more than most people give them credit for because act like a powerful circulatory assistant.
As trainers, we often think of calves as:
• “Jump muscles”
• “Running muscles”
• “A lower-leg hypertrophy target”
They’re all of those things, but it’s time we stop thinking of calves as just “just lower legs” and start seeing them as part of a bigger system helping blood move efficiently through the body.
