How to Improve Your Fitness With Variable-Intensity Interval Training (VIIT)

variable-intensity interval training workout

Story at-a-glance -

  • One way to help maximize the benefits of high-intensity interval training (HIIT) is to incorporate variable-intensity interval training (VIIT) into your routine
  • Many prefer VIIT compared to other methods of training because it’s a fun and quick way to achieve an effective full-body workout, while minimizing risk for injury
  • VIIT traditionally consists of low-, medium- and high-intensity segments that can include a wide variety of exercises ranging from agility and strength to high-intensity functional movements

By MASHUP™ Conditioning

High-intensity interval training (HIIT) has been a buzzword in the fitness industry in the last decade. 

HIIT and high-volume interval training (HVIT) are very common programs you will find in numerous gyms across the globe because they have proven to be one of the most efficient ways for an individual to achieve greater results1 in less time compared to lower intensity workouts.

That said, it has also led to an increase in injuries for many participants. Fabio Comana, an exercise physiologist and instructor at University of California San Diego, and a well-known leader in the fitness industry, has expressed concerns regarding the 4 percent increase2 in injuries related to overuse or chronic exercise in the last 10 years.

Therefore, we must learn how to enhance our athletic performance while keeping risk for injury low. It is important to recognize the growing need for medical fitness3 and training methods that support it.

Variable-intensity interval training (VIIT) method: This is one of the newest and safest ways to achieve maximum results in less time!

Why Variable-Intensity Interval Training (VIIT) Is so Beneficial

VIIT is a form of exercise in which you rotate between high-intensity interval training (HIIT) with medium-intensity (strength) and low-intensity (mind/body) recovery periods for a shorter, more efficient workout.

Typically, you quickly transition through all anatomical planes of movement and utilize your body's five major muscle groups. The high-intensity intervals should be performed close to maximum effort (90 percent intensity) and the recovery intervals should be done between 40 to 60 percent intensity.

By altering your intensity levels, you can get fitter in less time. VIIT reaps all the fitness and health benefits of steady state cardio with minimal risk of injury, in a fraction of the time, skyrocketing your metabolism after your workout!

Workouts can be specific to individual fitness components, but are ideally combined for a total body workout like we are suggesting.

By varying your workouts, the body is constantly adapting and improving upon its weaknesses, which can lead to greater results. When done appropriately the benefits include but are not limited to:

Enhancing athletic performance

Minimizing risk for injury

Decreasing body fat and increasing lean body mass

Improving posture and balance

Slowing the aging process

Improving insulin sensitivity

Improving mental well-being

Controlling blood pressure

Providing stress relief

Decreasing illness

Why You Might Choose VIIT as Your Preferred Exercise Program

VIIT training is very different in nature when compared to traditional HIIT, or even steady state exercise. The reasons individuals choose this type of training method can vary immensely.

Depending on the program, VIIT has the potential to be fun and quick while providing a total fitness experience. VIIT implemented with constant change in timing and exercises makes it almost impossible to experience a plateau in your fitness training results.

It naturally provides the benefits of periodization,4 which is a method many professional athletes use in their training. This increases adherence to a program and promotes sustainable results.

With VIIT you can experience the benefits5 of mind/body (yoga/pilates), agility and strength, and high-intensity intervals to add a new dynamic and ensure your entire body is always improving. After all, who really has time to spend several hours fitting in their cardio, strength and core?

VIIT also allows you to exercise between 40 to 90 percent effort throughout the duration of the workout, which lends itself to appear less intimidating and more inclusive of all types of individuals needing to work at their own pace.

Some VIIT programs include individualization that allows participants to choose options for each exercise so that a wide variety of fitness levels can participate in a workout together promoting a team atmosphere. 

MASHUP™ is one VIIT program leading the industry that uses this curated approach, and which has seen how it increases confidence in individuals, giving them a chance to see progression within each workout while also increasing their fitness level.

This type of approach makes it possible for novices and athletes to sweat together for a great workout. In a more scientific light, VIIT uses both aerobic (Type 1) and anaerobic (Type 2) muscle fibers. When performing steady-state exercise, we predominantly only use Type 1 fibers.

When utilizing Type 2 muscle fibers, you are more likely to increase your tolerance threshold for VIIT, which can allow the body to exercise at higher levels improving speed, joint mobility, strength, flexibility, balance, endurance and total fitness in general.

It can also stimulate your nervous, cardiovascular and respiratory systems far more significantly than other types of training. Lastly, it increases your aerobic capacity (VO2 max) by spiking your heart rate closer to your maximum limit. This enables you to work at higher levels resulting in harder, more efficient and effective exercise.

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What Are the Components of a VIIT Program?

High-intensity interval training (HIIT) alone saves time6 and produces numerous health benefits. However, using a VIIT formula is one of the best ways to combine your high-intensity cardio with core and strength exercises for maximum benefit and results.

Low-intensity Segment: This segment of exercises is intended to be slow controlled movements and to serve as the active recovery period during your workout. These movements have been described as full body movements associated with improved muscular strength, flexibility, balance and coordination, improved mental development and self-efficacy.

This could include a fusion of mind/body (yoga/Pilates) exercises to promote core strength and flexibility. A variety of these exercises have shown to help individuals decrease anxiety, decrease pain, enhance sleep, decrease the use of medication for post-surgical pain, decrease side effects of medical procedures, reduce recovery time and shorten hospital stays, strengthen the immune system, enhance the ability to heal and increase sense of control and well-being. 

One of the greatest benefits of mind/body exercise is preventing injury so that you can continue on your road to better health through high-intensity intervals and agility and strength exercises. They strengthen your entire core as well as help promote good posture leading to proper form and technique during strength and interval training. 

Regularly including mind/body exercises provides individuals with proper active recovery periods providing the body with full dynamic stretching and core strengthening. By incorporating these exercises in VIIT, the body has the most potential to achieve true HIIT intervals at 90 percent intensity every time they are performed.

Medium-intensity Segment: During this segment of your workout you want to focus on developing muscular strength, flexibility and endurance. Typically, agility and strength exercises can achieve these objectives and usually can only be performed for a short period of time before the muscles begin to fatigue and lactic acid is released.

While your heart rate may elevate some, you do not want to get breathless during this segment. The focus here is to feel your muscles burning. Basic elements of these movements require an individual to perform motor tasks ranging from dynamic gross activities to fine motor control tasks and include adaptive ability, balance, improved orientation, reactiveness and rhythm.

Benefits can include improved athleticism, injury prevention, neuromuscular adaptation and decreased recovery time, which will aid you in maintaining strength and balance as well as preventing injury in your everyday life routine. 

Often repetitive functional movements using just bodyweight or added hand weights or kettlebells can have a much greater impact on your overall muscular endurance and muscle tone versus using heavy weights because they utilize multiple muscle groups while engaging core balance simultaneously. 

They are one of the most effective ways to develop and maintain lean muscle mass. Some examples of these exercises include: plyometric lunges, plank deltoid fly raises, push-up jacks and squat thrust jumps.

High-intensity Segment: As the name suggests, the goal during this segment of your workout should be to perform every interval at 90 percent intensity. When performing any type of HIIT movement, you increase human growth hormone (HGH), which provides numerous health benefits, as your body's levels naturally decline after the age of 30. You know you are performing HIIT intervals correctly when it takes your body at least 30 seconds to gain your breath back.

An easy way to know if you have hit your target heart rate is to perform a talk test (e.g. repeat your phone number immediately after an interval without stopping to catch your breath). You should not be able to say more than three words consecutively without stopping to catch a breath. A VIIT formula is designed to achieve true HIIT7 intervals consistently throughout your workout.

Without an active recovery period, the level of intensity achieved during each interval steadily declines after the first couple have been performed which forces the body to progressively transition to an aerobic versus anaerobic workout defeating the purpose of the high-intensity intervals. 

Remember that HIIT is very effective, but can be abused by performing intervals for an extended length of time in any given day and result in injury as serious as rhabdomyolysis, a breakdown of muscle tissue that releases a damaging protein into the blood. In fact, if you are performing straight intervals for more than 20 to 30 minutes, you're probably not working hard enough to optimize the benefits of HIIT. Some examples of HIIT can include:

  • For walkers/joggers, pick up the pace for 30 seconds then slow down to regular pace for 30 seconds
  • For chair exercisers, make big quick arm movements for 30 seconds then relax for 30 seconds
  • Body weight exercisers can perform something such as a burpee or squat jumps for 30 seconds followed by 30 seconds of recovery

With the rise in popularity of fitness tracking devices, Comana has stated that it is important to understand that they are often inaccurate when performing VIIT workouts. It is better to focus on the actual workout experience, having less risk of injury, increasing HGH and the calories burned post-workout.

Due to the nature of VIIT consisting of low-, medium- and high-intensity segments, it ensures safety and effectiveness. In fact, more and more health professionals are confident to refer patients to try a VIIT program as one of the safest places to start or return to an exercise regimen where they will receive accountability, motivation and potentially significant results.

If you would like to experience this firsthand, we invite you to sweat it out by trying either the 15-minute digital or written sample workout included in this article.

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About MASHUP™ Conditioning

MASHUP™Conditioning, LLC was established in 2012 by Jamie Ford Zacharias, CPT, RN, MSN, NP-C and Stacy Redwine, CPT, BS Exercise Physiology/Pre-Physical, MA Missiology. They offer several options for individuals of ALL fitness levels to achieve their goals through their VIIT program, MASHUP™, that can be found at various gyms in Florida, Oklahoma and Texas including YMCAs, corporate and hospital fitness facilities.

They also offer 15-minute digital workouts via the Booya Fitness app, 15-minute DVD workouts and a 45-Day Fitness and Nutrition Online Challenge. For more information please visit