You eat a sandwich at your desk at 1pm. Twenty minutes later your blood glucose climbs and your insulin follows. You stay at the desk because a meeting starts in five minutes. By 2pm you feel flat, foggy, and reaching for coffee. The post-lunch glucose excursion drives a meaningful share of those slumps in healthy adults, and most of it builds while you sit still digesting.
The standard fix is a short walk after the meal. The 2022 Sports Medicine systematic review of crossover trials reported short light-intensity walks every 30 minutes during a sitting day lowered the post-meal glucose peak versus uninterrupted sitting. Most office workers in London do not leave the chair after every meal, snack and coffee. A 2022 paper in iScience tested a quieter seated option, a slow sustained heel lift driven by the calf muscle lying under the gastrocnemius. The team called it the soleus pushup. In a laboratory test of 25 healthy adults, sustained soleus pushups lowered the 3-hour blood glucose response to a sugary drink by 52 percent and the insulin response by 60 percent compared with quiet sitting.
The protocol is unusual, the science is mechanistic, and the results sit on one foundational paper rather than a stack of large trials. The Hamilton 2022 iScience finding is interesting but not yet proven in the wider population. The mechanism is biologically credible, the practical movement needs only a chair and two feet on the floor.
Why the soleus is different
The soleus is the deep calf muscle. It sits underneath the gastrocnemius, the bigger calf shape you see in the mirror. Both attach to the Achilles tendon and both lift the heel off the floor, but the soleus carries far more slow-oxidative type I fibres. Hamilton and colleagues cite anatomical work showing the soleus is around 88 percent type I fibres in their 2022 iScience paper. Older fibre-type surveys put the figure between 70 and 88 percent depending on the sampling region. Across the literature, the soleus sits at the high end of any human muscle for slow-twitch dominance.
Slow-twitch fibres do two things relevant here. They resist fatigue, so they keep contracting for hours without burning out. They run almost entirely on oxidative metabolism, so they prefer to pull glucose and free fatty acids straight out of the blood rather than relying on stored muscle glycogen. In the Hamilton 2022 iScience test, mild continuous soleus contractions raised local soleus oxygen use several times above resting baseline while whole-body breathing rate and heart rate barely shifted.
This combination is the point. The soleus pushup is not a strength exercise. It does not build muscle, raise heart rate to a training zone, or count toward the 150 minutes of moderate weekly activity in the World Health Organization guidelines. The aim is to keep the soleus contracting steadily while you sit, so it acts as a small glucose and fat sink for the bloodstream around it.
What the 2022 iScience study reported
The Hamilton 2022 paper combined several substudies in a single iScience article. The headline test compared a single seated session of soleus pushups against quiet sitting in healthy adults. Across 25 participants, the sustained soleus pushup protocol lowered the 3-hour glucose response to a 75 g oral glucose tolerance test by 52 percent and the matching insulin response by 60 percent versus seated control. The same Hamilton 2022 paper reported a roughly doubled rate of whole-body fat oxidation in the fasting window between meals and a drop in circulating VLDL triglyceride.
The protocol behind those numbers ran for about 270 minutes of cumulative soleus activity within the lab session. The team used surface electromyography to confirm the soleus was contracting while the larger gastrocnemius stayed quiet. The heel raises had to be slow, sustained, and full range to load the soleus and keep the gastrocnemius off the work.
Two caveats sit beside those numbers. First, this is one laboratory study in 25 adults with electromyography feedback. The translation to a self-coached desk worker without electrodes is plausible but not proven. Second, an oral glucose tolerance test is a stress test, not a normal meal. Whether mid-day soleus pushups lower the post-lunch sandwich response in real London offices to the same extent is open, and replication studies are now appearing in adults with prediabetes.
How sustained soleus pushups compared with seated control
The chart below shows the size of the reduction in two metabolic markers reported in the Hamilton 2022 iScience comparison. Longer bars mean a larger fall versus quiet sitting. Lower is better for both glucose and insulin in a healthy adult.
A simple desk protocol
The Hamilton group used electromyography to confirm the right muscle was firing. Without electrodes, the next best approach is to copy the movement pattern as closely as possible and keep the contractions steady, slow and full range. The four steps below match the technique described in the Hamilton 2022 iScience methods section.
Where this fits in a real day
The soleus pushup is a sitting tool, not a replacement for a walk or a workout. The WHO Global Recommendations on Physical Activity for Health published in 2020 still ask adults for 150 to 300 minutes of moderate aerobic activity per week and two muscle-strengthening sessions. NHS guidance backs the same numbers and adds the advice to reduce long stretches of sitting where possible. A desk worker who already meets those targets gains a small extra metabolic edge from soleus pushups on top. A desk worker who does not meet those targets gains more from a daily walk first.
The strongest case for soleus pushups is the meeting, the long train ride, the flight, or the focused block of writing where standing or walking is not realistic. In those windows, the seated heel lift gives the soleus something to do while the rest of the body stays still. Across the broader sedentary-behaviour literature, even small interruptions of prolonged sitting nudge cardiometabolic markers in the right direction. The 2022 systematic review in Sports Medicine pooled crossover trials and reported short light-intensity walks every 30 minutes during a sitting day lowered the post-meal glucose peak versus uninterrupted sitting. Soleus pushups occupy a similar niche when walking is off the table.
What the soleus pushup is not
The soleus pushup will not build calf size in any meaningful sense. The contractions are too light. It will not raise VO2 max, train your heart, or count toward the 150-minute weekly aerobic target. It is not a treatment for type 2 diabetes, and it is not a substitute for medical care, weight management, or a balanced diet for anyone with diagnosed glucose dysregulation. The Hamilton 2022 iScience trial was a one-day metabolic test in healthy adults, not a months-long clinical trial in patients.
Follow-up testing has begun in adults with raised glucose. A 2025 pilot study in the open-access journal Sports tested soleus pushups in a small group with elevated fasting glucose and reported a measurable drop in the post-meal response with the same heel lift pattern. Larger registered trials in adults with diabetic kidney disease are now listed on clinicaltrials.gov. Until those read out, the foundational Hamilton 2022 numbers remain the headline data.
Frequently asked questions
Bottom line
The soleus pushup is a small, specific tool with one foundational study behind it. In the 2022 iScience laboratory test of 25 healthy adults, sustained seated heel lifts cut the 3-hour glucose response by 52 percent and the insulin response by 60 percent versus quiet sitting. The mechanism is biologically plausible, and the movement is free, silent, and possible at almost any desk. Treat it as a small bonus on top of the basics, not a replacement. Daily walking, regular strength training, sleep and a balanced diet still drive the headline gains.
Sources
- Hamilton MT, Hamilton DG, Zderic TW. A potent physiological method to magnify and sustain soleus oxidative metabolism improves glucose and lipid regulation. iScience, 2022, volume 25, issue 9, article 104869. PubMed 36034224.
- 2022 Sports Medicine systematic review and meta-analysis of crossover trials on interrupting prolonged sitting with standing and light-intensity walking, pooled biomarkers of cardiometabolic health in adults, volume 52, issue 8, pages 1765 to 1787. PMC9325803.
- Fryer S, Paterson C, Turner L, Moinuddin A, Faulkner J, Stoner L. Localized activity attenuates the combined impact of a high-fat meal and prolonged sitting on arterial stiffness, A randomized controlled crossover trial. Frontiers in Physiology, 2023, volume 14, article 1107456. Frontiers in Physiology.
- 2025 pilot study in the journal Sports (MDPI), open-access, on the efficacy of the soleus pushup in adults with prediabetes, volume 13, issue 3, article 81. mdpi.com.
- World Health Organization. WHO guidelines on physical activity and sedentary behaviour. 2020. who.int.
- NHS. Physical activity guidelines for adults aged 19 to 64. nhs.uk.