Much research is being done in attempt to determine which type of exercise burns the most calories. Is it slow and long cardio? Is it intense weight training paired with bursts of cardio? Unfortunately, for every experiment administered there is also one that shows the opposite or a slightly different result. This can become confusing, especially when the media tends to side with whatever celebrity trainer or celebrity doctor, or talk show hosts deems as the “secret to losing weight.”
Thankfully there is some existing evidence that may help you understand the differences and the benefits of both.
One of the most confusing fitness myths is the cardio zone vs. the fat burning zone. This is an incredibly misleading statement. The “fat burning zone” is a slow steady pace for 60 minutes or more. Heart rate in this zone hovers around the 40-65% of your max heart rate or on a scale of 1-10 it would be about a 5 or 6. This form of exercise does use mainly fat as fuel. However, there is hardly any after burn associated with this type of aerobic activity. The “cardio zone” is a faster/more intense workout done for a shorter time period. This type of exercise uses more carbohydrate as fuel during the workout. But, what is hardly ever mentioned is the after burn from exercise in the “cardio zone.” After you finish an intense 30-45 minute workout you have depleted most of your glycogen stores. Therefore your body turns to fat as fuel for post workout recover. This helps to explain the effects of strength training.
Strength training, like intense cardio training, has an amazing effect of metabolism after you finish working out. According to the Journal of Sports Nutrition and Exercise Metabolism women can increase their fat burning metabolism by 60% for 16 hours after a workout! Men can elevate theirs by 19% for 48 hours after!
Combining the two has also proven an effective strategy. Intense strength training with intense bursts of cardio in between have been shown to increase fat loss by 10 fold (Journal of Strength and Conditioning Research).
So if a short intense workout is all you have time for then take a sigh of relief knowing that you are burning fat even after your workout.
If you are deconditioned and cannot maintain an exercise heart rate in your 85% of Max heart rate zone then it may be beneficial for you to do a longer workout to burn more calories.
Mix it up and do 2-3 longer workouts with 2-3 shorter intense workouts during the week. Tap into both zones and you’ll see results in no time.