CME INDIA Presentation by Dr. N. K. Singh, MD, FICP, FACP, Editor – www.cmeindia.in & Dr. Hanjabam Barun Sharma, MD, DSM. SEMS (Sports-Exercise Medicine & Sciences), PE-FLM (Performance, Environmental-Functional & Lifestyle Medicine) Lab, Department of Physiology, IMS, BHU, Varanasi Email: dr.barun.hanjabam@bhu.ac.in.
Salute Soleus Muscle
- Along with other calf muscles it is powerful plantar flexor.
- Soleus has a major contribution in running, walking and dancing.
- When you are seated calf raise (knees flexed approximately 90º), the gastrocnemius is virtually inactive. Then load is borne almost entirely by the soleus.
- Human soleus muscle tissue consists predominantly of slow twitch fibres.
- It is very important to understand that the soleal pump assists with venous return from the periphery to the heart when upright as the venous circulatory system passes through the muscle tissue.
- There is minimal glycogen contribution to fuelling the soleus. Instead of breaking down glycogen, the soleus can use other types of fuels such as blood glucose and fats. (Glycogen is normally the predominant type of carbohydrate that fuels muscular exercise.)
- Watch this to explore more:
What is “The Soleus Push up” (SPU)
- Dr. Hamilton and his colleagues from university of Houston have developed the soleus push up.
- Soleus Push up activates the soleus muscle differently than when standing or walking.
- The Soleus push up targets the soleus to increase oxygen consumption – more than what’s possible with these other types of soleus activities, while also being resistant to fatigue.
- While seated with feet flat on the floor and muscles relaxed, the heel rises while the front of the foot continues in one place.
- When the heel gets to the top of its range of motion, the foot is passively released to come back down.
- To simultaneously shorten the calf muscle while the soleus is naturally activated by its motor neurons is moto of the Soleus push up.
- The Soleus Push up movement is performed while seated.
- Hamilton’s method flips that upside down and makes the soleus use as much energy as possible for a long duration.
- It’s a very specific movement that right now requires wearable technology and experience to optimize the health benefits as per Dr Hamilton.
Why Soleus Push up is the need of the hour?
- There is also currently a high prevalence of prolonged sitting.
- Most of the people suffer from prolonged sitting (stated now as sickness) between 9 and 11 h/day at a low metabolic rate.
- Sitting behaviours is associated with metabolic and cardiovascular disorders.
- Soleus Push up can be done while you are seated and any time you want.
CME INDIA Discussion
Dr. Vasanth Kumar, Past President, RSSDI, Hyderabad:
- https://stories.uh.edu/2022-soleus-pushup/index.html
- This-muscle-in-your-calf-can-do-big-things-to-improve-the-metabolic-health-of-the-rest-of-your-body. This is an interesting piece of information which we need to discuss.
Dr. Hanjabam Barun Sharma:
- Many of us are already doing it as a habit.
- Many must have seen some people sitting and doing soleus push up unknowingly, just documented now only with its scientific reasoning.
Dr. Sanjay Kalra, DM (Endo), Bharti Hospital, Karnal, Haryana.
- Yes, I advise routinely to patients in OPD.
- It helps to reduce oedema as well.
Dr. Mohan T. Shenoy:
- Wondering if we can provide for authentic proof as more keep asking if this can translate to stopping few medicines.
- Only by moving a very small muscle located in the calf muscle behind the leg, called the soleus muscle.
- By moving this muscle while you are sitting in your chair and watching TV, the blood sugar level decreases by a large percentage (by half), and this muscle does not suffer any fatigue, even if you continue to move it for long hours.
- University of Houston Texas paper published at the end of 2022 is sparking a wave of interest.
Dr. Hanjabam Barun Sharma:
- It’s simple concept of application of type of muscle fiber as we learn once in physiology class.
- Soleus most consist of type 1 fiber or red muscle which is fatigue resistance & is most dependent on oxygen for its metabolism, and hence also called slow oxidative fiber.
- Due to the fatigue resistance property, we can do prolonged contraction of this muscle without fatigue and hence we can increase oxygen consumption considerably.
- This will contribute to energy expenditure considerably + fat oxidation during exercise so this is just extension of this logic.
Dr. Ganesh Mohan (Singapore):
- What I could not easily make out from the paper was the dose-response relationship. How much soleus pumping (~how many repetitions in how much time) did the participants do to achieve the reported (significant) decrease in post-prandial glucose levels?
Dr. Hanjabam Barun Sharma:
Let us scan Dr. Hamilton et al’s Research (Abstract of the Study). Ref-2
| Oxidative muscle, most notably the soleus, is inherently well equipped with the molecular machinery for regulating blood-borne substrates. However, the entire human musculature accounts for only ∼15% of the body’s oxidative metabolism of glucose at the resting energy expenditure, despite being the body’s largest lean tissue mass. |
| The study found the human soleus muscle could raise local oxidative metabolism to high levels for hours without fatigue, during a type of soleus-dominant activity while sitting, even in unfit volunteers. Muscle biopsies revealed there was minimal glycogen use. |
| Magnifying the otherwise negligible local energy expenditure with isolated contractions improved systemic VLDL-triglyceride and glucose homeostasis by a large magnitude, e.g., 52% less postprandial glucose excursion (∼50 mg/dL less between *∼1 and 2 h) with 60% less hyperinsulinemia. |
| Targeting a small oxidative muscle mass (∼1% body mass) with local contractile activity is a potent method for improving systemic metabolic regulation while prolonging the benefits of oxidative metabolism. |
Credit: Hamilton, MT. et al. (2022) iScience. A potent physiological method to magnify and sustain soleus oxidative metabolism improves glucose and lipid regulation.
Illuminating Findings:
Credit: Credit: Hamilton, MT. et al. (2022) iScience SPU contractions approximately doubled whole-body VO2 above the normal resting metabolic rate when sitting
Statement by Deborah Hamilton, senior research manager; Marc Hamilton, professor; and Theodore Zderic, research assistant professor University of Houston.
- All of the 600 muscles combined normally contribute only about 15% of the whole-body oxidative metabolism in the three hours after ingesting carbohydrates.
- Despite the fact that the soleus is only 1% of the body weight, it is capable of raising its metabolic rate during SPU contractions to easily double, even sometimes triple, the whole-body carbohydrate oxidation.
- We are unaware of any existing or promising pharmaceuticals that come close to raising and sustaining whole-body oxidative metabolism at this magnitude.
CME INDIA Learning Edge
- Dr. Hamilton et al’s research is ground-breaking in sense that the soleus muscle push up is very effective for improving the regulation of blood glucose.
- This study has identified the ‘soleus push up’ as the most effective exercise to improve Basal Metabolic Rate (BMR). Its effect lasts for hours, even while sitting. The soleus muscle if activated correctly, can sustain an enhanced BMR.
- Dr. Hamilton says – “We never dreamed that this muscle has this type of capacity. It’s been inside our bodies all along, but no one ever investigated how to use it to optimize our health, until now.”
- Unique fact of the soleus muscle: It does not rely on glycogen, allowing it to work for hours effortlessly without tiring.
- This study tested the soleus push-up by having subjects take a glucose drink and measuring their vital functions over the following three hours. It showed a 52% improvement in the excursion of blood glucose and 60% less requirement for insulin.
- Soleus muscle push-up doubled the normal rate of fat metabolism in the period between meals.
- This study could solve a variety of health problems caused by modern-day tendency to remain inactive for long periods.
CME INDIA Take-Away
| SPU, or “soleus push up contractions magnifies the normally low rate of carbohydrate oxidation by a small mass of muscle. |
| It becomes the most dominant tissue for carbohydrate oxidation in the entire body for the 3 h after ingesting glucose. |
| SPU contractions reduce VLDL-TG while raising fat and carbohydrate oxidation. |
| SPU contractions are a method to induce and maintain a relatively high local rate of oxygen consumption (VO2/min/kg muscle) during prolonged contractile activity. |
| A fundamental principle in exercise physiology is that a small muscle mass working in isolation can achieve a higher local oxygen consumption (VO2/min per kg) than when recruiting a large muscle mass. |
| SPU contractions improve postprandial glucose tolerance. |
| SPU contractions reduce postprandial hyperinsulinemia and insulin secretion. |
| SPU contractions increase carbohydrate oxidation during the OGTT. |
| Human soleus muscle is capable of raising, and sustaining for hours, the local rate of oxidative metabolism to high levels. |
| The high level of endurance of the soleus during SPU contractions provides a tool for reversing the otherwise slow rate of muscle metabolism during long periods of inactivity. |
| The Soleus muscle is only ∼1% of body weight, can sustain a sufficient metabolic rate for an impressive duration and improve glucose and lipid metabolism. |
We must know about limitations of the study
- This study was not a clinical trial.
- It was an experimental physiological study, conducted in highly controlled laboratory conditions.
- This study did not test effectiveness of a free-living lifestyle intervention.
- These studies only identified some of the immediate responses to SPU contractions.
- Muscle glycogen utilization was not measured in Experiment II (during the glucose tolerance test).
CME INDIA Tail Piece
How long one should do soleus push up?
- There aren’t any specific recommendations for the duration.
- The research had participants doing the movement continuously for around 4 hours at a time and not stopping for more than 4 minutes during soleus push up workout.
What is the triceps surae?
- It is used to group the muscles of the calf, is constructed by the soleus, the two-headed (medial & lateral) gastrocnemius and the plantaris muscles.
How do you perform a soleus push up?
Aim is to shorten the calf muscle.
| Sit with your feet flat on the floor and muscles relaxed. |
| Raise your heel, keeping your toes on the ground. |
| Release the heel when it is at the top of its motion and place it back on the ground. |
See it in action with a word from Professor Hamilton:
References:
- Dunstan D.W,Dogra S,Carter S.E.Owen N.Sit less and move more for cardiovascular health: emerging insights and opportunities.Nat. Rev. Cardiol. 2021; 18: 637-648
- Marc T. Hamilton, Deborah G. Hamilton, Theodore W. Zderic.A potent physiological method to magnify and sustain soleus oxidative metabolism improves glucose and lipid regulation.iScience,Volume 25, Issue 9,2022,104869,ISSN 2589-0042,https://doi.org/10.1016/j.isci.2022.104869.
- Effects of exercise amount and intensity on abdominal obesity and glucose tolerance in obese adults: a randomized trial.Ann. Intern. Med., 162 (2015), pp. 325-334
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