Weightlifting has become increasingly popular among amateur gym-goers, but is it good way to lose weight and does it really cause people to turn into Arnold Schwarzenegger?
Dr Andrew Scott, an expert in the health benefits of physical activity, discusses different types of weight control.
A large focus of health promotion is weight control, particularly in obesity. Since body shape is easy to see and measure it becomes an easy target for intervention. An easy target to focus on, but not so straight forward to intervene and bring about meaningful change. Calorie restriction and nutrient-restricting diets are often the go-to for many people wishing to improve their health. But these approaches carry their own limitations. As an adjunct or alternative to modifying diet, aerobic exercise is commonly used to increase energy expenditure since this is the component of daily energy expenditure that can be immediately increased with a single exercise session.
There are three components of daily energy expenditure: resting metabolic rate, thermic effect of feeding and physical activity energy expenditure. Resting metabolic rate is determined by our body mass: the heavier we are the more energy we expend, even at rest, therefore successful weight loss results in a lower resting metabolic rate. The thermic effect of feeding relates to the amount of energy that is required to metabolise the food we eat, therefore the less we eat the less energy we expend. These are both generally at a set rate on a daily basis, therefore it is clear to see how manipulating diet alone is problematic for reducing body mass.
The third component is physical activity -particularly exercise -which is planned, structured and has an end fitness or health goal in mind. Aerobic exercise has been promoted because it can expend energy relative to the duration and intensity of the exercise session being performed. Fitness expert Dr Kenneth Cooper became an exponent of running in his leisure time and in the 1960s he developed the Cooper Aerobics Institute in Dallas, Texas, with the aim to research and promote the use of running as a non-pharmaceutical health promotion intervention.
Its research programme suggested that aerobic exercise was important for prolonging life, thus must be important for maintaining peoples’ health and is why such exercise is so widely performed now. However, what if Dr Cooper’s hobby had been in the weight room rather than the open road? All modern international physical activity recommendations include recommendations for the frequency, intensity, time and type of physical activities, besides just aerobic exercise, across the lifespan and health levels. If Cooper had weightlifted perhaps resistance training would have been more mainstream a lot longer ago.
Now what if I told you that you could increase daily energy expenditure without moving? Resistance training involves taking muscle groups of the whole body through a full range of motion against an external resistance, such as machines, free weights, elastic bands or body weight, applying sufficient load and progressed over time to stimulate muscle growth. The more muscles that are stimulated the larger the growth. As the body’s muscles grow, even only a little, they metabolise more energy whilst at rest compared to lower muscle mass and during exercise they expend even more energy. Resistance training has other benefits by maintaining independence into older age and improving musculoskeletal and cardiometabolic health.
Resistance training is particularly useful during energy restriction through diets by maintaining resting energy expenditure and offsetting the reductions in thermic effect of feeding. The resistance trained person doesn’t necessarily acquire a physique like Arnold Schwarzenegger because a great deal of time and dedication is required to achieve such effects and is not required to gain the required health effects.
If somebody wished to improve their physique without necessarily losing kilograms from the weighing scales then resistance training, perhaps even combined with aerobic exercise, are excellent and effective methods to improve health and fitness.
Dr Andrew Scott, is Senior Lecturer in the School of Sport, Health and Exercise Science.
If Cooper had weightlifted perhaps resistance training would have been more mainstream a lot longer ago.