One of the most trendy workouts these days is interval training, in which participants alternate between higher intensity activities and lower intensity rest or relief periods. Naturally, this requires different rates of speed and degrees of effort.

The appeal of this type of workout is that it allows you to burn more calories without spending more time at the gym. Most interval training sessions are completed in 30 minutes or less.
Interval training has become a popular fitness regime in recent years because it is so effective. Interval training incorporates a lot of short bursts of high-impact cardio — such as jumping jacks, jumping rope and running in place — followed by low-intensity recovery periods. This type of workout is a very efficient way to quickly improve your fitness level.
According to a 2011 study presented at the American College of Sports Medicine Annual Meeting, just two weeks of high-intensity intervals improves your aerobic capacity as much as six to eight weeks of endurance training.
When performing intervals, participants will often get their heart rates up to at least 80 percent of maximum for short periods of time and then dial back down to a slow or moderate pace of 40-50 percent of maximum.
Many exercise adherents are now engaging in high intensity interval training (HIIT), which is typically performed in 20-minute bouts performed at 85-95 percent of maximal heart rate. The value of these shorter, higher intensity sessions is that they help fight boredom and pack a big punch in a relatively short period of time. Most HIIT workouts are completed in 30 minutes or less.
Those looking for an even more intense workout can try doing supramaximal interval training (SMIT), which involves performing all-out bursts of exercise, interspersed with full rest periods, or no activity.
Beginners might use a 1:2 work to recovery ratio, in which they work really hard for 20-30 seconds, for example, and then recover for 40-60 seconds. In essence, the recovery periods are twice as long as the high-intensity bouts.
As your conditioning improves, you might advance to a 1:1 ratio — 30 seconds of high intensity work, for example, followed by 30 seconds of recovery.
A common formula for more conditioned people involves a 2:1 ratio of work to recovery periods. For example, 20–90 seconds of hard sprinting alternated with 10–45 seconds of jogging or walking.
There are many different work/recovery formulas and you can experiment to find what works best for you. But remember, your body will eventually adapt and you will need to continually change the stimulus in order to accommodate that adaptation.
The beauty of intervals is that they’re not just for athletes and fitness enthusiasts. These routines can also benefit older folks and those with chronic conditions such as diabetes or heart disease.
Mixing in some interval training can produce additional benefits beyond that of steady-paced exercise.
Researchers in Australia have found that sprints as short as 8 seconds can be beneficial. Cycling three times per week, participants alternated between 12 seconds of slow, gentle peddling and 8 seconds of intense sprints, peddling as hard as they could. Despite the fact that they did this for 20-minutes at a time — meaning the actual hard exercise totaled just 8 minutes — the payoff was significant.
Over the course of four months, participants in the study, which was performed at the University of New South Wales, lost an average of six pounds of body fat. By comparison, those who cycled at a steady pace for 40 minutes, without mixing in the interval sprints, lost less than two pounds. Additionally, participants who performed intervals improved both their blood pressure and blood sugar readings.
The same interval techniques can be applied to running, swimming, rowing, stair-climbing or hill-climbing. Again, you don’t necessarily need to keep the high-intensity bursts to 20 seconds. You can also try 30-second blasts or even longer periods — whatever suits you.
The Australian protocol was very similar to Tabata training, which consists of performing an activity all-out for 20 seconds, resting for 10 seconds, and then repeating the on-off sequence for four minutes total.
Keep in mind that the recovery or rest period in your intervals is just as important as the high intensity period since it helps to strengthen your heart. Rapidly raising your heart rate and then dropping it creates ventricular remodeling, which allows greater cardiac output and improved performance.
One of the best measures of fitness is aerobic capacity, or the ability of the heart and lungs to get oxygen to the muscles. As your cardiovascular fitness improves, you’ll be able to exercise longer and/or with more intensity.
Since high-intensity interval training is, well, intense, it shouldn’t be overused. Your body needs adequate time to recover between workouts, so it’s best to limit your HIIT workouts to three days per week. Light to moderate, steady-state aerobic exercise is ideal on your recovery days.
One of the most important elements of high-intensity interval training is a proper and adequate warmup, which should be at least 5-10 minutes long. This will prepare your body for the high-intensity workout to come.
Beginners shouldn’t rush into strenuous workouts before their body is ready, or else they may injure their muscles, tendons or bones. Instead, start slowly and, as your stamina improves, challenge yourself by increasing the intensity or the duration of your intervals.
The best workout plan combines interval training with a comprehensive strength training plan. Muscle is a metabolically active tissue; your body uses it to burn fat. So, the more lean muscle tissue you have, the more calories/fat you’ll burn throughout the day, even while you sleep. Simply put, more muscle tissue requires more energy.
As always…. Get in Motion. Stay in Motion.