As Cunha et al. point out in the intoduction of their latest paper, "previous research investigating the effects of intermittent vs. continuous exercise upon EPOC superficially matched the exercise bouts for external work (same intensity and duration), the exercise volume was not matched by the actual EE [energy expenditure]" (Cunha. 2015).
In other words, you if you want a fair comparison you have to make sure that the intra-workout energy expenditure is identical and cannot compare 10 minutes of steady state exercise to 2x5 minutes of steady state exercise, because it's not a given that the workload will be absolutely identical: Only if you standardize the workout volume by measuring the energy expenditure and make sure that the the exercise intensity and cardiorespiratory fitness levels of your subjects are taking into account you will be able to objectively compare the effects of continuous and intermittent exercise on the magnitude of EPOC.
In their latest study Cunha et al. tried to do just that, when they had ten healthy men, aged 23 to 34 yr, performed six bouts of exercise
- firstly, two maximal cardiopulmonary exercise tests for running and cycling to determine exercise modality-specific peak oxygen uptake (VO2peak); and
- secondly, four isocaloric exercise bouts (two continuous bouts expending 400 kcal and two intermittent bouts split into 2 x 200 kcal) performed at 75% of the running and cycling oxygen uptake reserve.
Beware! This is not a HIIT vs. LISS study! At first I thought that this would be another HIIT vs. LISS comparison, but this is not the case. It's a comparison of two forms of steady state exercise, where one is classic, i.e. training for roughly 30 minutes, while the other was designed to consume the exact same amount of energy, albeit in two sessions seperated by 1h of rest.The exercise bouts were separated by 72 h and performed in a randomized, counter-balanced order. The VO2 was monitored for 60-min postexercise and for 60-min during a control non-exercise day.
|Figure 1: It's quite obvious - the more muscle you train, the higher your EPOC is going to be. Plus: If you do interval training, your total EPOC will exceed the amount of fat burned after isocaloric continuous exercise (Cunha. 2015).|
In the end, both, the exercise type (cycling = less muscle vs. running = more muscle) and modality (continuous vs. intermittent) both had a significant effect on net EPOC, where running elicited a higher net EPOC than cycling (mean difference = 2.2 L, P <0.001).
- Cunha, Felipe A., et al. "Effect of continuous and intermittent bouts of isocaloric cycling and running exercise on excess postexercise oxygen consumption." Journal of Science and Medicine in Sport (2015).