High Intensity Exercise: Best Way to Get Ripped
by: Robbie Durand
If your looking to lose fat and build strength than high-intensity interval training (HIIT) is the training for you. Initial research evidence strongly supports the idea that HIIT is indeed the most effective way of inducing fat loss – both subcutaneous and abdominal. HIIT is intense exercise performed with an all out effort for a short time followed by low intensity exercise or rest for another fixed time with repetition of these cycles. This can be done using any piece of aerobic equipment like a spinning bike, rower or a treadmill.
The latest craze, CrossFit, with an almost cult-like following, is an HIIT protocol with exercises done against time – back to back and, thus, involving no rest at all. The traditional HIIT workout usually consist of a warm-up followed by a pattern of 30 to 40 seconds of a high intensity exercise followed by a period of 15 to 20 seconds of a lower intensity exercise. Repeat this pattern for 15 to 20 minutes with a target heart rate of somewhere between 70 to 90 percent maximum during the high intensity segments. Another popular HIIT training The Tabata method consists of a basic warm up followed by 20 seconds of an ultra-intense exercise that targets large muscle groups followed by a 10 second rest period. Repeat the 20/10 cycle eight times for a four-minute workout. Maximum heart rate should be between 90 and 100% during the 20 second bursts.
Much to the disbelief of many cardio and treadmill walkers, traditional slow, long-duration aerobic activity of low to moderate intensity (as in brisk walking or jogging) in causing fat is negligible. Performing HIIT does some pretty amazing things to enhance fat loss compared to traditional steady state aerobic exercise such as: Elevated levels of post-exercise oxygen consumption – meaning you keep burning calories after you are done with the exercise session and increased mobilization of fatty acids due to increased catecholamine (adrenaline and noradrenaline) secretion induced by HIIT. Another interesting benefit to HIIT is that it suppresses appetite.
Researchers at the University of Western Australia in Perth decided to examine if HIIT had any impact on reducing appetite. The results of the small but significant study suggests that intense exercise sessions – such as the popular HIIT and Tabata workouts – lead to short-term suppression of appetite.
Researchers had subjects exercise on bike continuously for 30 minutes at a moderate pace at around approximately 65% of their predetermined maximum aerobic capacity. In the other session the men completed 30 minutes of HIIT interval riding. They rode for one minute at 100 percent of their endurance capacity, then cycled gently for 4 minutes and repeated. In the final session, the men rode for 30 minutes for intervals of 15 seconds at 170 percent of their normal endurance capacity followed by pedaling for one minute at 30 percent of their maximum capacity. After each 30 minute session the men were provided a standardized liquid breakfast. About 70 minutes after the exercises sessions, the subjects were taken to a table loaded with sweetened but bland porridge and were allowed to eat as much as they wanted.
After the higher intensity training, the men weren’t as hungry, on average, consumed 200 fewer calories than the moderate pace exercise group. The researchers also took blood draws from the subject before and after exercise and measured the levels of the hormone ghrelin, which is known to stimulate appetite. After the higher intensity sessions the men not only had lower levels of ghrelin, but also measured higher levels of both blood lactate and blood sugar, which act as natural appetite suppressants. So one of the potential mechanisms in which HIIT reduces fat loss is thru a reduction in appetite in addition to revving up metabolism.
Bilski J, Teleglów A, Zahradnik-Bilska J, Dembinski A, Warzecha Z. Effects of Exercise on Appetite and Food Intake Regulation. Med Sport 2009; 13(2):82-94.