Quentin Marsman
The last few years people are increasingly hitting the gym to work on their physique, most importantly to lose fat. Most men start lifting to increase their muscle mass and acquire the beloved six-pack, whereas most women jump on the treadmill to burn calories and ultimately lose fat and weight. The new Dutch guideline for sports and exercise from 2017 advises people to do muscle and bone strengthening exercises next to cardiovascular exercises, like playing football or running on a treadmill [1]. The question then arises which of these two methods of exercise is actually superior when looking at the way it contributes to fat loss.
To compare the number of calories burned between sports, we can use the metabolic equivalent (MET) values. One MET is defined as the energy needed to lie or sit quietly or the consumption of 3.5 mL O2/kg/min [2]. When we compare running with strength training we see that the MET value of running (on a treadmill) is 7.00, while strength training has a mere 3.00, i.e. running burns more calories than lifting [2]. However, strength training has additional benefits for the energy expenditure of the body. This effect is twofold. Firstly, when doing strength training, microtrauma occur in muscles which require energy to repair. According to a study by Westcott, this effect holds on for about 72 hours and increases resting metabolic rate (RMR) during this time from five percent to nine percent [3].
The second effect of strength training is a long term effect, namely the chronic increase in RMR. The same study by Westcott shows an approximate seven percent increase in RMR after several weeks of lifting [3]. The theory behind this suspected increase in RMR is based on the fact that the resting metabolism depends for a great deal on the energy expenditure of muscles, with muscles contributing to around 30% of the total resting metabolism [4]. Increasing muscle mass would lead to more energy spend by muscles and thus increasing the RMR. However, this effect is debatable as some research shows the effect, whereas other studies fail to detect this increase. A study by Lemmer et al. managed to show the increase in RMR in men but failed to show this effect in women [5].
Concluding, cardiovascular training and strength training have two different effects on your body. Where cardiovascular training burns more calories during the exercise, strength training burns more calories in the long term. While both methods serve their own place in losing fat, lifting seems to have a more long term effect via the increased resting metabolism. So, looking at that sixpack, running seems to give it to you faster, but lifting seems to have the edge, due to its long term effect.
[1] Gezondheidsraad. Beweegrichtlijnen 2017. (Gezondheidsraad, Den Haag, 2017).
[2] Tudor-Locke, C., et al. Linking the American Time Use Survey (ATUS) and the Compendium of Physical Activities: methods and rationale. Journal of physical activity & health 6, 347-353 (2009).
[3] Westcott, W.L. Resistance Training is Medicine: Effects of Strength Training on Health. Current Sports Medicine Reports 11, 209-216 (2012).
[4] Zurlo, F., et al. Skeletal muscle metabolism is a major determinant of resting energy expenditure. The Journal of Clinical Investigation 86, 1423-1427 (1990).
[5] Lemmer, J.T., et al. Effect of strength training on resting metabolic rate and physical activity: age and gender comparisons. Medicine and science in sports and exercise 33, 532-541 (2001).