Results from a study published in Medicine & Science in Sports & Exercise suggest that repeated max-intensity sprints yield better fat loss results than longer duration, low-moderate intensity cardio.
There were 20 participants who were split into two groups.
Each group ran 3 times a week for 6 weeks.
Group 1 performed max intensity sprints. 30 seconds in duration, 6 sprints per session, 4 minute rest between sprints.
Group 2 ran for 30-60 minutes at 65% intensity.
At the end of the 6 week study,the Sprinting group reduced fat mass by 12.4 %. The low-moderate intensity group reduced fat mass by 5.8 %.
Moral of the story ? Integrate sprint routines into your repertoire. I wouldn’t fully abandon low-moderate intensity cardio all together, but you better get those sprints in.
Benefits of Sprinting
1) Sprinting will reduce body fat and increase overall strength. It will do so much faster than long, low-intensity cardio because sprinting requires maximal recruitment of muscle. Sprinting also targets fast twitch fibers. Fast-twitch fibers are thicker than slow twitch fibers.
2) Sprinting can naturally increase human growth hormone. This can lead to increases muscle mass, enhancement of the immune system, weight loss, and increased stamina.
3) Sprinting strengthens your cardiovascular system with brief bursts of high intensity followed by long periods of recovery. You strengthen and develop your muscles by doing heavy, low-repetition sets with long recoveries. You should strengthen your heart the same way.
How to Properly do Sprints
1) Start your workout by warming up for about 5 minutes. This can be a light jog.
2) Measure out a distance from 50-100 yards (or meters) long. The objective is to sprint at least 8 seconds. This is when your body will begin to send the signals that produce human growth hormone. Do 5-10 repetitions. You could also use a heart rate watch to keep a log of your calories burnt.
3) Between repetitions, walk slowly at least twice the distance that you ran. Rest time should be about 1-2 minutes. Don’t jog to “keep your heart rate up.” The goal is to fully recover so that you can sprint at full speed. If towards the end you need a little more time, take it.
4) Regardless of what you have planned, if you reach a point where you can’t sprint due to fatigue, stop and come back stronger next time. Jogging to “finish” the workout defeats the purpose as you are seeking high intensity with low volume, not low intensity with high volume.