Running for endurance and weightlifting for muscular growth are two examples of activities that assist you in reaching your fitness objectives. But if you want to improve your strength, speed, or fitness, interval training is a great way to do it.
If physical health and fitness were a spectrum, one end would be endurance, or the capacity to sustain an effort over time. Strength, or the body’s power to exert force, is the other. Interval exercise is effective for enhancing both.
The Definition of Interval Training
According to Jenna Gillen, Ph.D., associate professor of exercise physiology at the University of Toronto, “interval training is an umbrella term for exercise protocols that involve alternating between periods of relatively high-intensity exercise with periods of recovery.”
Interval training is a versatile kind of exercise that may be utilized to improve your endurance, strength, or both. An infinite number of interval training routines may be devised depending on one’s activity, goals, and current fitness level.
Workouts typically consist of a series of intervals, each involving an activity performed at a certain intensity for a predetermined duration or distance. After then, there will be a time of reduced activity or relaxation. What sets interval training apart from steady state, or continuous, exercise training is the peaks and valleys in intensity.
Although interval training is most commonly associated with cardiovascular exercises (such as running, cycling, rowing, swimming, and jumping rope), it may also be incorporated into strength workouts to increase speed, power, and general fitness.
According to exercise scientist and Certified Personal Trainer Jim White, CPT, the goal of interval training depends on the individual. As a rule, interval training is excellent for enhancing stamina and speed.
White likewise praises the efficacy of interval exercise for slimming down. “It is an exceptional method for burning calories and decreasing body fat percentage,” he explains, “while still providing a significant increase in muscle strength, depending on the exercises performed and the focus of the training.”
Common Interval Exercises
There are many different kinds of interval training. Interval training may be considered a general term for any exercise that consists of alternating bouts of intense exertion and rest.
Martin Gibala, Ph.D., professor of kinesiology at McMaster University in Hamilton, Canada, says, “Some people have this notion that interval exercise is only this all-out, as hard as you can go effort — but that’s not the case.” That’s probably because HIIT is so popular, even though interval training comes in many varieties.
Even if your regular workout consists of strolls around the block, Gibala says you may still reap the benefits of interval training. For example, he cites a study published in Diabetes Care in February 2013 in which Danish researchers followed persons with type 2 diabetes who had been put on a walking program. Both groups walked, but one walked at a steady, moderate speed while the other walked slightly faster for a few minutes before slowing down again.
Compared to those who walked continuously, “after several months, the interval walkers were fitter, had dropped more body fat, and improved their blood sugar control to a greater extent than the continuous walkers,” he adds.
Some of the most common types of interval training are as follows. Interval training, as Gibala puts it, “has a style that is suitable for just about anyone.”
1. Interval training at a high-intensity level
“Near maximal” efforts are the emphasis of high-intensity interval training (HIIT), with goal heart rates often between 80% and 95% of your maximum. A “work” time might be as short as a few seconds (for less-skilled persons) or as long as several minutes. The intensity of the effort is more essential than the duration of the period. High-intensity interval training requires an essentially maximum effort level.
2. Practice Sprints
Sprint interval training (SIT) involves short bursts of work at a near-maximal intensity at regular intervals. Cycling or jogging at 100 to 150 percent of your maximal heart rate is an example of a sprint interval training session. Athletes with more experience or greater fitness levels are the ones who commonly undertake these kinds of training sessions.
The Tabata technique, sometimes lumped in with high-intensity interval training, is a work-to-rest ratio program that includes 20 seconds of extremely hard labor followed by 10 seconds of relaxation. You will continue this routine for the next four minutes or eight total sets. Olympic speedskaters trained at an intensity of 170 percent of their VO2 max during the 20-second attempts, according to seminal research published in Medicine & Science in Sports & Exercise in October 1996. This form of interval training is more accurately described as sprint training than high-intensity interval training.
4. To perform fartlek exercises
Swedish for “speed play,” this interval training style is popular among distance runners due to its lack of organization and emphasis on having fun. Fartleks are performed by interspersing periods of higher-intensity effort with a steady-state run at more random intervals (for example, picking a lamp pole or mailbox up ahead of you and picking up the pace until you reach that landmark) than the rigid periods of most interval training workouts. It’s an excellent strategy for preventing mental tiredness and boredom midway through exercise.
Strength trainers have embraced the interval training method, Every Minute on the Minute (or EMOM). This type of training requires you to complete a certain number of repetitions of a single exercise within 60 seconds. Rest for as long as time is left in the minute, then proceed to the next set. Because resting time decreases according to how slowly you finish the exercises, working harder in less time is rewarded.
6. Interval Training, Low Intensity
This type of exercise, also known as Low-Intensity Interval exercise (LIIT), has gained popularity over the past decade as a method to get the advantages of interval training without the stress of High-Intensity Interval Training (HIIT) or sprint training. While other interval training methods may have you working at 95% or more of your MHR, LIIT typically has you working at 70% to 80% of your MHR throughout the intervals. The Cleveland Clinic suggests doing the same exercises you would in HIIT training, such as jogging, rowing, or even weight lifting, but at a reduced intensity. This is a fantastic choice for seniors or those just beginning an exercise program or recovering from an ailment.
The Value of Interval Training
Interval training is a popular exercise method since it has been shown to improve health and fitness in a wide variety of ways.
Interval training, like any other form of exercise, may reduce body fat, boost strength and endurance, and positively affect health. The time savings over steady-state training is a major benefit (and factor in their widespread acceptance).
In a study published in Applied Physiology, Nutrition, and Metabolism in March 2014, Gillen and her team found that after just a few weeks of HIIT training, a wide variety of adults showed significant improvements in their aerobic capacity, skeletal muscle oxidative capacity, exercise tolerance, and markers of disease risk.
According to Gibala, who cites a big 2006 research published in the European Journal of Cardiovascular Prevention and Rehabilitation as part of the HUNT research that tracked more than 55,000 participants for 16 years, exercise may not be necessary three times a week to get some of the advantages. The HUNT trial found that even one session per week of vigorous exercise lowered the risk of cardiovascular mortality in both sexes. Thus, he concludes, “Even one weekly bout may be beneficial.”
Furthermore, a study published in Nature Medicine in December 2022 found that people who did at least three episodes of vigorous intermittent lifestyle physical activity (i.e., a movement that was incorporated into their daily lives rather than a dedicated workout) had a 40% reduction in their risk of dying from any cause, a 49% reduction in their risk of dying from cancer, and a 49% reduction in their risk of dying from cardiovascular disease.
Can Weight Loss Be Achieved Through Interval Training?
Many people who train out at the gym do so in the hopes of seeing a reduction in their waist size or weight. Undoubtedly, it’s a plus when it comes to interval training.
White claims that interval training is an effective means of losing weight. “You’re burning many calories, which can positively affect your metabolism and cardiovascular system.”
He argues that making those changes might make it easier for your body to get healthy and increase the efficiency of your cardiovascular system. Being physically fit makes it simpler to lose weight.
Is Interval Training Safe?
Setting unrealistic goals for oneself while beginning a new exercise routine is simple. Interval training novices often report feeling more tired than usual during and after their initial weeks of training. You can injure yourself by pushing yourself too hard, too soon, especially with high-intensity interval training and sprint training.
If you’re just getting started with a fitness regimen or getting back into it after a lengthy break, take it easy at first to reduce the likelihood of injury and burnout. New guidelines from the American College of Sports Medicine (ACSM) say sedentary adults in good health should begin low- to moderate-intensity exercise without waiting for a doctor’s OK and that they can increase the intensity gradually if no adverse effects occur.
You can begin with LIIT for a few weeks and, if you feel OK, gradually increase the intensity of your intervals.
To be sure it’s safe to begin an exercise program of any intensity, the American College of Sports Medicine (ACSM) still advises sedentary people who have or show signs of cardiovascular, metabolic, or renal illness to consult a physician first.
Top-Notch Interval-Training Routines
There are many options for discovering the most effective high-intensity interval training (HIIT) exercises and interval regimens to follow, including HIIT activities at home. However, Gillen insists that the key is not to overthink the situation.
Interval training consists of “alternating between relatively intense exercise and rest periods,” as she puts it. There is an indefinite number of possible protocols, and many different types of exercise and interval times yield positive results. Choose an activity you enjoy and make it a part of your daily workout schedule.