Exercise, muscle mass and good health…By Dr Garth McLeod

Blog #3 by Dr Garth McLeod, Weight loss and General Surgeon, in his series of blog articles for Yeppoonie Smoothie.

This piece focuses on the following questions.  Why is exercise important? Why is maintenance of muscle mass important? And how do these help to maintain good health?

The answers to these questions are both simple and complex. I’ll start with the simple answer first….and the complex answer in later posts.

In short, we are biologically designed to move…a lot. As a species humans evolved over several million years, and certainly over recent hundreds of thousands of years,  primarily as hunter-gatherers. Our basic physiological functions, metabolism, enzymatic pathways are all tuned to and adapted for a life where a lot of energy was expended getting food. And furthermore the food source was not guaranteed. This also explains to a significant extent why obesity has become such a problem for “modern” humans. Dr Mike Stroud, in his enlightening book “Survival of the Fittest” published 25 years ago, put it succinctly thus- “There is a now a discrepancy between our biological design and what we do and eat. It is a discrepancy with considerable implications.” An increasingly overweight and obese population is one such implication with a multitude of diseases on the increase as a consequence of this obesidemic.

Exercising is what we were designed to do. When we do not exercise there becomes an imbalance, a mismatch, between our physiological function and design and the environment within which those mechanisms are at play. Unfortunately for many people this results in the accumulation of fat. Once this storage of fat exceeds a certain quantity then it becomes harmful to the organism (person) and ultimately results in disease or diseases associated with obesity. These include high blood pressure, diabetes, sleep apnoea, high cholesterol, heart disease and many more. We have been designed to move but we have also been designed to store energy. We can store energy very efficiently. This stored energy is deposited as fat. Corporeal fat is stored in the subcutaneous tissue (beneath the skin) and this is obvious. Visceral fat is stored in and around the viscera (organs) with the abdominal cavity and chest. This can be less obvious and in some cases an individual may be “thin fat”- this individual has the external appearances of someone in good health with a healthy weight. But scanning shows dense deposition of fat in the viscera and around the heart. This leads to poor metabolic health and can result in early heart attacks and strokes and indeed all the diseases we typically associated with morbid obesity. This phenomena notwithstanding visceral, or truncal, obesity is typically also easily identified by an individuals habitus. These are typically males and carry the excess fat centrally (truncally). The limbs are often not affected but there is an appearance centrally often colloquially termed a “beer gut” and not uncommonly is associated with excessive alcohol intake. This is also described as male pattern fat deposition where as female pattern is typically corporeal fat distributed more or less evenly around the abdominal wall, breasts, thighs and buttocks. There are of course exceptions to these general rules and there is a spectrum of fat deposition. Nonetheless whatever you wish to call it, excess energy (consumed calories) is stored as fat. This is an age old adaptation to food sources being unreliable and frequently unavailable. Thus the capacity to store energy as fat would have been a physiological advantage in times of food scarcity. This adaptation has persisted. However for most people today living in developed countries there is no food scarcity. I would qualify that statement and note there is often a paucity of quality food (whole food)  but none so that exists with the calorie rich and nutritionally poor offerings that are readily available in supermarkets around the world.

Building and maintaining muscle mass can offset calorie excess to a certain degree but a balanced diet is important for all aspects of health. Muscle mass is closely related to your BMR (basal metabolic rate) and is directly proportional to your lean body mass (muscle). There are also numerous other factors that contribute to the BMR including age, sex, exercise intensity, acute illness and in females hormonal influences around menstruation. Muscle mass is however the most modifiable factor and hence the critical importance of exercise and muscle mass maintenance in good health. Resistance and strength training builds and maintains muscle depending on the regime. It is largely agreed that “time under tension” builds muscle mass. There are nuances of this approach that continue to be the subject of debate but for the average individual (not an elite athlete) this concept is applicable. Lifting weights. Body weight exercises. Calisthenics. Pilates. Yoga. These all put muscles under load, under tension and improve mass and function. Equally other important components of the musculoskeletal system including tendons, ligaments, joints and bones show improved function and metabolic health in people who regularly exercise by way of resistance and strength training. Cardiovascular training can also be very useful and is the subject of a later post.

More and more evidence based scientific research is giving us a better understanding of muscle. More pertinently not just as an organ that helps us to move, stand upright, show emotions, sprint, climb mountains, run for more than 24 hours, break bricks, pull a truck and other remarkable feats, but as an organ integrally related to overall metabolic health. Muscles interact with and contribute to immune function, cognitive capabilities, gut function and mental health wellness amongst other complex interactions.

We were designed to exercise. We were designed to maintain muscle mass. This is imperative for metabolic health.

Get to it and do what biology designed you for……