Low intensity or high intensity cardio. Which is better for weight loss?
This is a very popular question. In the ‘80’s everyone worked out as hard as they could. If someone suggested that they exercise for 45 minutes of 4-5 times a week, they were doing 90 minutes, 7 days a week. Then people ended up with overuse injuries, were burnt out and were no longer interested in exercise. The media had to change the message to encourage people to exercise again, so the message changed to “work out at a slow intensity for a longer duration”. In the ‘90’s, people’s idea of exercise was to walk around the block with a garden hose in one hand and a low fat sandwich in the other. In 10 years we went from one extreme to the other. In regards to your cardio work out then, what really is the best advice?
We have two sources of energy stores. Fat stores and carbohydrate (muscle glycogen stores). Everyone burns energy at their own personal rate that they metabolize calories. For sake of argument though, let’s say that if the average person walked for one hour, they would burn approximately 100 calories. Due to the low intensity of the exercise, they may burn 60% from fat stores and 40% from carbohydrate stores. Great news right? That is 60 calories from fat stores and 40 calories from carbohydrate stores. Now that is just about all that the media told us, so in the 90’s people were strolling around and thinking they were making great gains in their work out routines. Here’s what they didn’t tell us…
Yes, it is true, that if we work out at a higher intensity, we will burn a lower percentage of calories from our fat stores. These are not precise numbers, but again, at an educated guess, if you work out at a high intensity, you may burn 60% of your calories from carbohydrate stores and only 40% from fat stores. What they didn’t tell us though is that when you run for an hour, you may burn up to 700 calories. In this case 40% (calories burned from fat stores) of 700 is 280 calories which is much more than the calories burned from fat stores from an hour long walk.
Of course not everyone can run for an hour, or run at all for that matter, but that is part of the fun. In every work out, to increase your fitness level and burn more calories, you should challenge yourself to work a little harder or a little longer than your previous work outs. Everyone can set that goal. Your alternative is to continue working out at a low intensity and just exercise a little longer each time. Remember though, that if you want to increase your fitness level and burn more calories and you decide to take this approach, you may want to pack a lunch…to prepare for your daily walk to the next city and back!
Change of intensity and change of duration is a really effective way of creating a cardio routine that stimulates weight loss. At Fit 'N' Well, I often recommend that clients participate in 3 interval cardio sessions and two long duration cardio sessions to best stimulate weight loss.
Next time we’ll talk about why it is important to change your routine every 4, 6, or 8 weeks.
Until Next Time,
Keep Fit ‘N’ Well.