Yet another reason to shorten your workouts! One point the researchers [see links below] didn’t mention is that cutting a 60 minute workout down to 30 allows you to work with greater intensity. It’s been proven over and over that intensity is more important in exercising for fat loss than duration.
And when it comes to doing cardio for fat loss, we first need to take a look at the landmark study from Tremblay, Impact of exercise intensity on body fatness and skeletal muscle metabolism.
The Tremblay study states:
… the activity of muscle glycolytic enzymes was increased by the HIIT [from Stephen: that’s “High Intensity Interval Training”] program, whereas a decrease was observed following the ET program [that’s “Endurance Training,” you know, that slow, boring cardio you’re going to stop doing as of right now].
The enhancing effect of training on muscle 3-hydroxyacyl coenzyme A dehydrogenase (HADH) enzyme activity, a marker of the activity of beta-oxidation, was significantly greater after the HIIT program. In conclusion, these results reinforce the notion that for a given level of energy expenditure, vigorous exercise favors negative energy and lipid balance to a greater extent than exercise of low to moderate intensity. Moreover, the metabolic adaptations taking place in the skeletal muscle in response to the HIIT program appear to favor the process of lipid oxidation.
Here’s the bottom line with that study …
When you equate calories burned while exercising, the interval training group burned nine times more fat. Did you catch that? Nine times the fat!
So you’re getting better results AND doing it in less time. (Oh, it’s harder work, by the way. Hey, you can’t have everything!)
Personally, ever since I got Geoff Neupert’s Kettlebell Extreme program (not nearly as scary as it sounds), I’ve cut most of my workouts down to 30 minutes total. (I still walk for about an hour once a week for technical reasons we’ll cover in another post.)
So, how long do you work out and why that magic number of minutes? (Hint: There’s no physiological reason to exercise for exactly 60 minutes.)