High Intensity Interval Training (H.I.I.T.) is an effective and intense training method that maximizes your training time to yield dramatic progress and results.
HIIT is especially effective in incinerating fat, improving endurance and moving beyond stubborn plateaus. This training system targets your cardiovascular system with alternating periods of short intense, fast paced anaerobic exercise with less-intense, aerobic recovery periods and typically these workout sessions usually last 10-20 minutes due to the high intensity and energy required. 30 second intervals are a good place to start when beginning this method of training. This requires you to highly increase your energy expenditure (after a thorough warm up) and rate of exertion for 30 seconds followed by less intense work (aka active recovery) for 30-60 seconds. This is repeated for sets for the duration for your total exercise time. Start with 6 intervals in your first attempts of HIIT. If you are striving to train above your lactate threshold, you need to go fast enough and feel that the last few seconds are really intense and feel almost impossible to keep going. As your endurance increases, progress to 60 second HIIT with 2 minutes of less intense work (active recovery) and over time, decrease your active recovery time to 60 seconds.
HIIT increases the amount of calories you burn during your exercise session and post exercise but due to the increased physical demands required, a greater length of time is needed for your body to recover from each exercise session. This method of training is not recommended for beginners.