High-Intensity Interval Training (HIIT) is an exciting workout protocol that benefits most populations. Sometimes modifications are necessary and other times variety is warranted just to mix it up. Each personal training client has his or her own preferences and needs, with fitness level being necessary as a variable to consider. Personal trainers should have a varied toolbox of options to stave off boredom and keep clients engaged. Let’s explore six variations for HIIT.

If your clients are looking for a faster and more effective way to burn fat, lose weight, or build muscle, interval training is one solution. By implementing short bursts of intense activity in your client’s workout, they will quickly enhance their workout routine and meet their weight-loss goals.

Interval training is defined by the American Council of Exercise (ACE) as “alternating short bursts of intense activity with active recovery”. Active recovery is a less intense form of the working exercise. The short bursts of intense activity are known as anaerobic activity (without oxygen) and the active recovery is known as aerobic activity (with oxygen). Interval training utilizes both forms of activity which is one of the big advantages of this type of training. (Source: American Council on Exercise ).

Benefits of HIIT

Interval training burns more fat! If your client maintains a constant moderate workout, their weight loss will likely plateau. By adding interval training to the workout routine they can increase the amount of fat burned by over 30 percent, even during low-intensity workouts.

Interval training helps improve cardiovascular fitness. Because interval training incorporates aerobic activity as well as anaerobic, it helps control blood pressure, increase energy, and burn more calories.

In a study done by the University of Guelph, researchers found that after implementing interval training into a workout, cardiovascular fitness increased by 13 percent (Source: Science Daily ).

Interval training adds variety. Psychological benefits cannot be overlooked. Interval workouts are a great way to break up monotonous routines whether a client is trying to build muscle or focus on weight loss.

Interval Training for Beginners

If your client is a beginner to interval training, a good understanding of the basics is paramount for a safe and effective workout.

In order to avoid injury and to ready the muscle for interval training, warming up is essential. A warm-up might consist of at least five to 10 minutes of a light activity such as walking, jogging, biking, or elliptical or mobility work. Afterward, perform a few dynamic stretches to complete the warm-up. Do not stretch a muscle cold before warming up.

There are four essential components to interval training: intensity, duration, recovery, and repetitions. A basic interval training program includes these four variables and should be adjusted to fit your client’s goals. For now, we’ll focus on the first two.

Intensity levels for interval training range from 1, no intensity at all (standing still), to 5, a light jog, and to 10, or “all-out” 100% effort intensity. Interval training beginners should never reach 10 and instead remain in a comfortable intensity zone.

Duration of the interval should be determined by the trainer and by the client’s stamina or energy level. It could range from 2 minutes for beginners or 15 minutes for more experienced clients. For example, if your client typically walks 2 miles in 30 minutes he/she can increase the intensity of their walk or run for a few minutes and then return to their original speed.

Just as your client must warm up his or her muscles before the workout, they must also cool down the muscles with a light five-minute aerobic activity and static stretching and/or self-myofascial release to promote ample recovery.

Tabata–the Original HIIT

In the 1990’s Izumi Tabata introduced a protocol that employs a 2:1 work-to-rest ratio in an 8 cycle: 20 seconds work, 10-second recovery, 4 minute round. Unlike traditional interval training where protocols use equal periods of work to rest, HIIT interval work-to-rest ratios are unbalanced. In some cases, recovery may be: during transitions, lower-intensity work, or on an as-needed basis.

These work-to-rest ratios are attributed to some powerful physiological benefits. HIIT workouts have been reported to lead to improved cardiovascular and metabolic outcomes: O2 efficiency and cardiac output (VO2) increase, and fat is used for fuel due to an increase in lactate production.

HIIT Workout Considerations

Before clients jump into a HIIT routine, make sure they do a dynamic warm-up targeting the muscles and joints in the kinetic chain that will be called upon in the workout. Finish with a bit of aerobic to anaerobic work. 

Exercise selection is just as, if not more, crucial as the work-to-rest ratio. Explosive, and compound movements really help recruit type II muscle fibers, and keep the heart rate up high enough to work close to that VO2 max. A basic HIIT workout is performed circuit style; one exercise is performed at a high intensity for a period of time, usually 30 seconds, followed by 30 seconds of rest.

As everything in fitness, HIIT has evolved over time. Let’s take a look at some protocols that utilize different work-rest ratios.

Six Variations of HIIT Protocols


Pyramids are similar to circuits: clients are given a few movements to complete in rounds. In each round the number of repetitions changes. Pyramids can be done in ascending order, descending order, or both.


Set the clock for 60 seconds and give clients 2-3 compound exercises to complete 6-10 repetitions of. Let them rest until the next minute strikes indicating they start again, and you’ve got an Every Minute On the Minute (EMOM) routine.

The recovery period in this protocol depends on how long it takes to get through the routine. The more times they complete it, the less rest time they’ll likely have between minutes.


Unlike traditional interval or even HIIT training, As Many Rounds As Possible (AMRAP) is a protocol that doesn’t have any prescribed work and/or recovery time. A timer is set, and clients are given a set number of exercises and reps to do of each exercise. Their goal is complete as many rounds of the set exercises as they can in the set time.

Rest is really only introduced when the timer buzzes.

To-Do List

A similar take on the AMRAP idea, give clients a time limit and a set of compound exercises. Usually, I make the number of repetitions high, like 50, and encourage them to break work into smaller batches in any order they wish.

Active recovery comes in while transitioning between movements.


Add on routines can also be treated like AMRAP: set the time and number of movements. The number of the movement is also the number of repetitions to complete. The client always starts back at number 1. For example, the client starts with 1 rep of exercise 1. Then, 1 rep of exercise 1 and 2 reps of exercise 2. Then, 1 rep of 1, 2 reps of 2, and 3 reps of exercise 3.


In the traditional Tabata profile, clients complete 1 exercise with a 2:1 work-to-rest ratio

Work time 20 seconds
Rest time 10 seconds
Number of exercises       1 exercise
Number of cycles 8
Total time 4 minutes

Cardio and Strength Training Adapted Tabata Profile

In order to give clients the opportunity to work on both their cardiovascular and muscular endurance, the Tabata single exercise protocol is sometimes modified to include 2-4 exercises with the same 2:1 work-to-rest ratio.

Work time

20 seconds

Rest time 10 seconds
Number of exercises      2/4 exercises
Number of cycles 8
Total time 4 minutes

Example 1: Two exercises (one cardiovascular, one strength)

      Cardio: Leapfrog forward, fast feet back

      Strength: Dumbbell thrusters

In the above example, both movements are done for 20 seconds and the 10-second break between, (which really functions more as a transition), and would be repeated 4 times each, for a total of 8 cycles, in 4 minutes.


Sample HIIT Tabata Protocol in Action

As you can see there are many ways to apply variations for HIIT to a fitness training program. Enjoy experimenting with the many options. You nor your clients will never get bored.

Theresa Perales

Theresa Perales has an MA in Spanish, and is an ESL teacher at San Diego State University (SDSU). After years of struggling with her weight, she decided to give exercise a try. A passion for health and fitness grew instantly and inspired her to become certified as a personal trainer with NFPT, and as a group fitness instructor with AFAA Group Fitness and Madd Dog Athletics® Spinning. Theresa believes that nutrition and fitness are not about aesthetics but ultimately about feeling healthy and empowered.