Perform sprints to burn fat and lose weight. Sprinting can also improve your immunity! If all-out repeated sprints seem too hard, high-intensity intervals will also burn fat and elevate immunity to a much greater degree than steady-state aerobic exercise.
A new study in the European Journal of Applied Physiology showed that the greater amount of time an individual spends above the anaerobic threshold, the greater the effect on fat burning and growth hormone (GH) production. Immunity is also boosted much more when you cross the anaerobic threshold.
High-intensity training is so effective because anaerobic exercise elevates the expression of gene activity by nearly 75 percent over steady-state aerobic exercise. The new study compared the effect of a short 15-minute high-intensity exercise test to exhaustion with a 30-minute aerobic exercise test on gene and white blood cell activity. Much of the high-intensity test was spent above the anaerobic threshold, whereas the aerobic test was below the threshold. Both tests boosted immune activity and stress response, but the high-intensity trial triggered a profound increase to gene activity that is involved in fat metabolism and hormone growth factors.
Fat metabolism as well as protein and glucose metabolism were all elevated in the activity of at least 310 genes following the 15-minute high-intensity trial. In comparison, 69 genes were upregulated after the 30-minute aerobic trial, the majority of which were related to immunity and a few that were involved in glucose metabolism, meaning the obvious boost to the immune system and burning of carbohydrates.
This study provides another way of understanding why sprints will burn fat and can build muscle, whereas steady-state training has a more catabolic effect on lean tissue. The high-intensity trial triggers growth factors that boost the proliferation of muscle cells and tissue, making you stronger and increasing lean mass. Sixteen genes that are directly involved in fat metabolism were activated in the high-intensity trial that were not active following the steady-state aerobic test.
In half the time, you can complete a high-intensity workout and get more than fat burning benefit! Tailor your high-intensity training program to your needs. If you play sports, shorter sprints with short rest intervals may be ideal. For recreational trainees who want to burn fat, keep the overall workout time brief and intense for best results. Effective workout protocols include 6 sets of 30 seconds with 4 minutes of recovery, or 60 sets of 8 seconds with 12 seconds of recovery (yes, that is 60 sets, but you complete 3 sets a minute and the whole workout is done in 20 minutes). More moderate intensities for longer intervals have also shown to be effective, but the research data of fat loss is not as dramatic.
Sakharov, D., Maltseva, D., et al. Passing the Anaerobic Threshold is Associated with Substantial Changes in eh Gene Expression Profile in White Blood Cells. European Journal of Applied Physiology. 2011. Published Ahead of Print.