Summer is just around the corner and along with it comes the time of vacations, swimming and another shirtless activities. If you haven’t perfected your summer body yet (but you want to), there is a very effective way to achieve that – sprints.

If we take a closer look on sprinter’s physique, we could assume that his training style will be efficient for leaner, muscular body with less body fat. However, the first research paper that investigated this problematics is kind of recent, from 1994! The study showed great results by adding short (15-30s) and long (60-90s) interval trainings versus simple aerobic training group. By adding the intervals to regular aerobic training regime, participants lost more fat. All of this despite the fact, that caloric expenditure was two fold higher in aerobic running group! How does this work then, you ask?

Counting your caloric intake and expenditure is still relevant, if your goal is to improve body composition. For achieving fat loss, it’s ALWAYS necessary to be in caloric deficit, but the caloric expenditure DURING training is not that relevant. The key role in this process is excess post-exercise oxygen consumption, shortly EPOC. EPOC expresses the caloric expenditure in 48-hour window after your training is done. EPOC rises with higher intensity of activity, and during interval training, the intensity is around 90% or higher. The increase in basal metabolism (BM) is crucial for fat loss. On the contrary, during aerobic activities, your body is trying to be as effective as possible with its energy resources, and your BM is decreasing! Add some deliberate caloric deficit (your trying to lose weight) that will decrease your BM even more, thus failing to expell fat from your body.

Along with increased intensity over your anaerobic threshold, releasing of growth hormone and insulin-like growth factors IGF-I and IGF-II is rising. These insulin-like factores directly improve the effect of growth hormone in tissues. They act as counter-parts to insulin and maintain correct insulin sensitivity in tissues, which can be often disturbed. In this case, we talk about insulinoresistency, which can manifest over time as diabetes mellitus II. type. These growth hormone improving effect is often attributed to adipose tissue hormone – adiponectin, which is released during training. Another effects like decreasing tissue inflammation, optimalization of free fatty acids in muscles, liver and adipose tissue, along with feeling of satiety. Count the effect of testosterone, and you get the ideal fat-burning environment.

Another great benefit of interval training is time efficiency. Classic style of cardio in its pure form takes 35-60 minutes raw time. Average interval training, where we do 5x 30s sprint with a 2-3 minute pause in between sets, is done in 15 minutes!

So, how should you now implement this knowledge and create the best traning for fatloss?

• total beginners – 8 seconds of 100% effort follow by 12 seconds of leisure tempo, best done on bike erg, where you start on 5 minutes total and increase the lenght of training to 20 minutes
• beginners again – one minute of fast running followed by one minute of rest, repeated 10 times
• experienced trainees seeking to lose fat – try the famous Wingate protocol, where you sprint for 30s and rest for 4 minutes, repeated 4-6 times, as you progress in training, you can reduce the pause in between or add more repetitions
• conditioning for experienced athletes – try hillsprints, you can choose from 30-60s long sprint, the rest is moderate walk to the place you started sprinting, repeated 5-8x
• power athletes – 10x 35m sprint with 10s rest in between
• collective sports – challenge yourself with track sprints in this order – 400m sprint, rest 4 minutes, 300m sprint, rest 3 minutes, 200m sprint, rest 2 minutes, sprint 100m, rest 1 minute, repeat as you like

Do not forget that sprinting doesn’t mean simply running on track! You can use hillsprints, AirBike, SkiErg, or pushing a sled, the only limit is your imagination.

Sprint training can be a insurmountable challenge for some individuals, however your effort is going to be worth it as hell! Improved cardiorespiratory parameters, healthier heart and lungs, VERY high metabolic turnover lasting many hours after your training is done, increased basal metabolism, improved mood, literal flood of growth and anabolic hormones, which directly improve your body compositions are the rewards you get for tough sprint.