Metabolism

Strength training and muscle building promote metabolic health

Our system of muscles is our largest metabolic organ. Muscles are crucial to bone, sugar and fat metabolisms and so, energy/heat conversion together with hormonal balance are largely dependent upon muscle condition. Metabolic disturbances don’t just happen of their own accord. Apart from genetic risk factors that we cannot influence, individual lifestyles play an important role in determining whether we are likely to develop a metabolic disorder. Strength training not only increases muscle strength but also improves metabolism and so acts to prevent diseases that are typical of our modern developed world, e.g. adult-onset diabetes, high blood pressure, disorders affecting the fat metabolism and arterial sclerosis.

Strength training needs energy

At each training session you expend some 120 to 200 kilocalories (500 – 840 kilojoules), women somewhat less than men and the young consume somewhat more than the old. Even after the training session, energy consumption remains high as energy is required for regeneration purposes. Provided that you do not increase your calorie intake when you take up strength training, the composition of your body will gradually change: the percentage of muscle will increase and the percentage of fat decrease. As muscle is heavier than fat, you won’t necessarily lose weight but you will look slimmer.

Energy consumption and basal metabolic rate

Strength training is a good way to counter a loss of muscle mass and the effects of reductions in calorie intake/need. Poorly developed muscles combined with excess body fat can upset energy metabolism and increase the risk of adult-onset diabetes, metabolic disorders and cardiovascular disease.

Strength training helps to develop and maintain muscles that are healthy and metabolically active. Regular training produces a long-term increase in basal metabolic rate and has a positive influence on our metabolic condition (Graves & Franklin 2001, Pedersen & Saltin 2006).

Blood pressure

High resting blood pressure represents a risk to the heart because it indicates that the heart is in a state of constant overload and damage can occur to blood vessel walls. Even elevated normal blood pressure – the precursor to high blood pressure – is dangerous for vessel walls. Strength training reduces elevated normal blood pressure for up to two days following a training session. Regular strength training reduces blood pressure by about 5mm Hg and so reduces the risk of heart attacks and strokes.

Diabetes as example (Type 2 diabetes mellitus)

…shows the effect of our training on the metabolism: During the digestive process, glucose enters the blood in large quantities. This glucose is then transported by means of the pancreatic hormone insulin into the muscle cells where it is consumed. If the sensitivity of muscle cells to insulin declines, the body has to produce more and more insulin in order to maintain the control system. Eventually, the pancreas is unable to cope with the demand. Blood sugar concentrations increase and blood vessels, nerves and in the end complete organs are damaged. High levels of muscle activity improve the effectiveness of insulin, reduce blood sugar levels and protect against the dreadful consequences of diabetes.

In short: metabolic disorders are often the result of the unhealthy lifestyles particularly prevalent in the developed world. Obesity, diabetes mellitus Type 2, high blood pressure (hypertension) and poor cholesterol levels often interact with one another and collectively are known as a metabolic syndrome.