The soleus push up (SPU) is a chair-based exercise that may improve your metabolic health. Created by University of Houston researcher Marc Hamilton, the SPU works your soleus muscle.
Soleus is Latin for “shoe” and refers to the deep muscle in your calf that only makes up 1% of your body mass. When properly activated, it can produce large amounts of oxidative metabolism while you sit for hours on end.
Hamilton discovered that compared to other muscles, your soleus uses less glycogen (stored carbohydrates) and burns glucose from your blood, as well as fats, much more effectively.
This means your soleus never fatigues from activity since you have all the fuel you need in your bloodstream all day long. A 2022 study in iScience found that activating the soleus properly can dramatically elevate local muscle metabolism—doubling fat oxidation between meals and improving blood lipid profiles.
What Is The Soleus Muscle?
Your soleus runs underneath your gastrocnemius muscle (the bulge you see in the back of your calves). It is comprised of slow-twitch muscle fibers that contract slowly and are used for endurance-based activity.
Doubling Fat Oxidation Between Meals: Because your soleus primarily uses blood glucose and fats for fuel rather than glycogen stores, properly engaging it can increase muscle metabolism in that area of your body by 2x between meals and boost your blood lipid panel.
Key Benefits for Metabolism & Fat Loss
- Sustained calorie burn — Raises local muscle metabolism to high levels for hours (not minutes), using a fuel mix heavy on blood glucose/fats → can burn ~200 calories in 130 min or ~400 in 270 min of accumulated activity.
- Blood sugar regulation — Improves glucose excursions by up to 52% over 3 hours post-meal (better than many touted methods like intermittent fasting or standard exercise in some contexts); reduces insulin needs by ~60%.
- Enhanced fat oxidation — Doubles normal fat metabolism rate during fasting periods between meals; lowers triglycerides and VLDL (“bad” blood fats) for better lipid profiles.
- Anti-sedentary hack — Counters sitting’s metabolic slowdown → preserves muscle, fights insulin resistance, and supports overall metabolic health without needing to stand/walk.
- Low-impact & accessible — No equipment, zero cardio strain, fatigue-resistant (soleus is built for endurance), ideal for office, couch, or travel.
It’s not a “magic bullet” replacement for full workouts or diet, but stacking SPUs throughout the day amplifies fat-burning efficiency and helps create a larger calorie deficit over time.
The study involved 25 men and women of different ages and body mass indexes to see if doing soleus pushup for four and a half hours a day would change their metabolism. “We never dreamed that this muscle had this ability. It’s been in our bodies all along, but no one has studied how to use it to optimize our health? until now,” said Marc Hamilton, the study’s lead researcher.
How to Do Soleus Push Up Correctly (Step-by-Step)
This is not a standard standing calf raise—form is crucial for soleus-dominant activation (bypasses gastrocnemius for max metabolic effect).
Starting Position:
- Sit on a chair, bench, or edge of a desk/bed with knees bent at ~90 degrees (thighs parallel to floor, shins vertical).
- Feet flat on the floor, hip-width apart, toes pointing forward (or slightly out if comfy).
- Spine neutral, core lightly braced—relax upper body (no tension in shoulders/quads).
The Movement:
4. Push through the balls of your feet → slowly lift heels as high as possible (full plantarflexion, like tiptoeing while seated).
5. Focus on shortening the soleus (feel the deep calf contract below the gastroc).
6. Hold the top for 1–2 seconds (max contraction) → squeeze calves hard.
7. Slowly lower heels back to the floor under control (full range, no bouncing).
8. Repeat smoothly — aim for continuous, rhythmic contractions without momentum.
Key Form Tips:
- Keep knees fixed at 90° — don’t let them extend or rock forward/backward.
- Unloaded ankle (no added weight initially) → emphasizes soleus over gastroc.
- Slow, controlled tempo (2–3 sec up, 1–2 sec hold, 2–3 sec down) → sustains activation.
- Breathe normally — no breath-holding.
- Avoid using quads/hamstrings — isolate to calves.
Common Mistakes to Avoid:
- Raising knees or rocking body (shifts load away from soleus).
- Fast/bouncy reps (reduces metabolic efficiency).
- Partial range (limits activation).
- Standing version (changes muscle recruitment).
Programming for Max Results
- Duration/Volume → Accumulate 1–4+ hours/day in short bursts (e.g., avoid >4 min inactive). Start with 10–20 min sessions, build up.
- Frequency → Daily, especially post-meals or during desk time — stack with work calls, TV, reading.
- Intensity → Low-effort (feels easy); use EMG-style focus if possible, but most feel it in deep calf.
- Progression → Add light ankle weights later or increase hold time for more burn.
- Sample Routine:
- Desk workday: 5–10 min every hour (or continuous low-key while typing).
- Post-meal: 15–30 min to blunt glucose spike.
- Total goal: 2–4 hours accumulated for noticeable metabolic boost.
Expected Results
- Short-term (days–weeks): Better energy stability, reduced post-meal crashes, subtle fat oxidation increase.
- 4–8 weeks: Improved insulin sensitivity, lower fasting glucose/triglycerides, easier fat loss (with diet).
- Long-term: Enhanced metabolic health, less sedentary damage, compounded calorie burn.
Sit down: This little-known muscle can transform your life if you’re sitting for long periods. Do soleus push up before/after your HIIT workout, walks or weight training for even more benefit! Right now, sit at your desk and simply raise/lower your heels for 5 minutes. You’ll feel your calves working overtime. Metabolism boost incoming.
