I’ve been getting questions about this lately and wanted to address the question of whether sprint sessions are better for calorie expenditure than moderate intensity cardio.
Many people (on both sides of the fence) have impassioned opinions that they like to defend but let me show you what the data says…here is the study…
Comparison of energy expenditure elevations after submaximal and supramaximal running. Laforgia J, Withers RT, Shipp NJ, Gore CJ. Exercise Physiology Laboratory, School of Education, Flinders University of South Australia, Adelaide, Australia. Although exercise intensity has been identified as a major determinant of the excess postexercise oxygen consumption (EPOC), no studies have compared the EPOC after submaximal continuous running and supramaximal interval running. Eight male middle-distance runners [age = 2.1 +/- 3.1 (SD) yr; mass = 67.8 +/- 5.1 kg; maximal oxygen consumption (VO2max) = 69.2 +/- 4.0 ml.kg-1.min-1] therefore completed two equated treatments of treadmill running (continuous running: 30 min at 70% VO2max; interval running: 20 x 1-min intervals at 105% VO2max with intervening 2-min rest periods) and a control session (no exercise) in a counter-balanced research design. The 9-h EPOC values were 6.9 +/- 3.8 and 15.0 +/- 3.3 liters (t-test:P = 0.001) for the submaximal and supramaximal treatments, respectively. These values represent 7.1 and 13.8% of the net total oxygen cost of both treatments. Notwithstanding the higher EPOC for supramaximal interval running compared with submaximal continuous running, the major contribution of both to weight loss is therefore via the energy expended during the actual exercise.
Now let me summarize the findings...the authors wanted to equate the work done between both bouts (i.e. energy/calorie expenditure) so that subjects in both groups burned the same amount of calories DURING the exercise.
To do this group 1 had to run at 70% of VO2 max (about 85% HR max) for 30 min.
Group 2 had to do what I would consider quite a difficult series of 20 x 1 minute sprints at 105% of VO2 max with 2 min rest between runs. That’s a 60 min exercise bout for this second group!
When all was said and done (taking into account the calories burned AFTER the exercise was over), after 9 hours, the “sprint-type” group burned more total calories after the exercise. How many more? A WHOPPING 33 calories.
So, you can either go out and sprint for 1 min intervals separated by 2 min rest for a total of 1 hour at this high intensity and burn 539 cals. Or you can run for 30 minutes and burn 483 calories.
That extra 30 minutes of sprinting gets ya 56 more calories burned!
Now, none of this even speaks to what is actually burned. The interval bouts will undoubtedly burn more carbs while the continuous more fat. And if you want to talk catabolism, which do you think is more catabolic when you look at time spent and calories burned?
So, doing the continuous running, you are more time efficient and burn more fat (and may be less catabolic).
For those guys on here who continue to tell me Im wrong about cardio and that sprinting is the best way to get lean…here is the data…