What is HIIT?

What is HIIT?

bootcampWHAT IS HIIT?
High-intensity interval training (HIIT) is a short duration (15-60 Mins) exercise regime characterized alternating intervals of intense work followed by rest intervals. It is not uncommon for work intervals to approach 80% to 95% of one’s maximum heart rate (MHR) combined with rest intervals at a much lower effort (eg, 40%-50% of MHR).

What are the benefits of HIIT?
HIIT training has been shown to improve:

  • aerobic and anaerobic fitness
  • blood pressure
  • cardiovascular health
  • insulin sensitivity (which helps the exercising muscles more readily use glucose for fuel to make energy)
  • cholesterol profiles
  • abdominal fat and body weight while maintaining muscle mass.

Why is HIIT Training so Popular?
HIIT workouts are becoming hugely popular, but why?

HIIT Workouts:

  • Save time by allowing you to achieve similar benefits to endurance training in shorter periods of time
  • Burn as many or more calories during workouts with the added benefit of continuing to burn calories during the post-exercise period (EPOC)
  • Can be modified for people of all fitness levels and special conditions
  • Can be used in older and at risk adult populations by adjusting intensity levels to stay within 50-70% MHR
  • Can be performed on all exercise modes, including cycling, walking, swimming, aqua training, elliptical cross-training, and in many group exercise classes.

Is HIIT Training Safe For Everyone?
Regardless of age, fitness level, risk factors, or special conditions, the key to safe participation of HIIT training is to modify the intensity of the work interval to an appropriate intensity. At risk populations can increase intensity levels under supervision of a medical professional, as safety in participation is a primary priority. The safety of HIIT is increased tremendously when individuals focus on finding their own optimal training intensities as opposed to keeping up with other persons or following a specific protocol that may push them beyond their own capacity.



  1. American College of Sports Medicine (ACSM) HIIT Brochure: http://www.acsm.org/docs/brochures/high-intensity-interval-training.pdf
  2. American Journal of Lifestyle Medicine: High-Intensity Interval Training –An Alternative for Older Adults; Michael Whitehurst, EdD, FACSM

Effective Cardio Training Part 2

As I mentioned in my last article, effective cardiovascular training is a crucial factor in for many fitness related goals including athletic goals, weight loss and general health. In this post, I’d like to share with you some of my secrets for developing cardio programs.


In order to get the most benefit from cardio training, I recommend making continual adjustments and tweaks to three variables:

Duration: Length of time spent for each individual cardio session
Intensity: Level of difficulty achieved during each cardio session
Variance: Varying the type of cardio performed each session

Obviously the length of your cardio training sessions has an impact on total calories burned, cardiovascular endurance and cardiovascular health. While basic recommendations from the American College of Sports Medicine and American Heart Association are to do moderately intense cardio 30 minutes a day five days a week, or to do vigorously intense cardio 20 minutes a da, three days a week, for healthy adults under the age of 65, it’s also important that your cardio training correlates with your personal fitness goals, whether they involve weight control, fat loss or are more performance oriented.

High Intensity Interval Training (HIIT)
HIIT has become a very popular fat burning method. HIIT uses intervals of time and assigns them a personal intensity level. Normally you’ll “max out” and then recover during the next interval. HIIT is great for breaking personal records and gives you a personal challenge during every workout. Not only that, research suggests that HIIT causes the body to burn more energy for a longer period of time after the workout is complete (fat burning while doing nothing!). The main drawback to HIIT is for beginners in fitness. This type of workout can be intimidating, and, if done incorrectly, it could be overly exhausting to the point of becoming nauseating. Whenever performing HIIT, it should always be based on personal intensity index. It is important to understand how hard you can work.

Steady State Training (SST)
SST is a constant, steady effort throughout the entire cardio session. You’ll keep your personal intensity from 7 to 9 (on a scale of 1-10) the entire session. This type of cardio session will also cause the body to demand more energy when your workout is complete, although not as much as HIIT.

Low Intensity Cardio
Low intensity cardio is great for active lifestyle activities, beginners in fitness, those recovering from injury and the elderly. While you do burn mostly fat while doing cardio at a lower intensity level, you will not get the benefits of post-workout energy demand. Because of this, LILT is an inefficient method for burning fat. You can achieve more benefits in a shorter period of time by using the various other methods suggested here.

One commonly overlooked component of cardio training is variance. By variance I mean using different methods of cardio each time you train in order to elicit an adaptive response. Variance is especially important if your goals include weight loss, fat loss or general fitness. By using different types of cardio such as running, jump rope, step mill, biking, elliptical, etc., your body attempts to become efficient at each activity (as opposed to becoming efficient at just one activity). Continually changing type of cardio you do will not only improve overall fitness level but also will increase your total calories burned.

The method I’ve found to be most effective in getting cardio results is by laying out a weekly a monthly plan that incorporates each of the variables mentioned on different days. Are you wondering how you can use these principles to maximize the effectiveness of your cardio training plan? If so, leave your questions and I will do my best to answer them below.

Effective Cardio Training Part 1

Young Woman Working Out

Effective cardiovascular training is a crucial factor in many fitness related goals including athletic goals, weight loss and general health. In this article, I would like to add to your knowledge and understanding of cardio training so you can design a program that leads you to your goals.

When I was just starting out in fitness, I was certain that I could achieve all my goals by running an hour (or more) every day. I figured the more cardio I did (no matter what the type), it would make me a better volleyball player, help me lose the weight I wanted to, and get me in great shape, since I had so much endurance. I was wrong! While I did develop a lot of endurance, I still struggled to be as fast as I wanted during volleyball matches, reacted a little slower than I hoped and had trouble staying at the weight I wanted. In other words, I was in good health and decent shape but the results I was after stayed just out of my reach.

It wasn’t until I learned to apply the simple tips I’m about to describe that I finally the results I wanted.  In order to get the most benefit from cardio training, I recommend making continual adjustments and tweaks to three variables:

  • Duration: Length of time spent for each individual cardio session
  • Intensity: Level of difficulty achieved during each cardio session
  • Variance: Varying the type of cardio performed each session
Remember, the purpose of each training session is to stimulate the systems of the body with a certain type of load (weights, cardio, etc.) and elicit an adaptive response from each session.  A cardio training plan that continually adjusts each of the three variables places a new stimulus on your muscles, tissues and cardiovascular system and challenges the body differently each time you work out.
A simple example is that of marathon training.  A standard training schedule for beginners starts with three to five miles or so at week one and gradually increases distance runs (load) each week. The body adapts to each distance you run, and each week you have the ability to sustain more.



Adaptive response to exercise:

The body’s response to the demand placed upon it during an exercise session

Obviously the length of your cardio training sessions has an impact on total calories burned, cardiovascular endurance and cardiovascular health.  While basic recommendations from ACSM and AHA are to do moderately intense cardio 30 minutes a day, five days a week, or to do vigorously intense cardio 20 minutes a day, three days a week, for healthy adults under the age of 65, it’s also important that your cardio training correlates with your personal fitness goals whether they involve weight control, fat loss or are more performance oriented.

For example, if your goal is weight loss, you may want to increase your cardio from 20 minutes three times a week to 30 minutes five times a week; this would allow you to burn more total calories each week.  Or, if your goal is to become a better basketball player, you may want to train for speed two times per week and train for endurance two times per week.

As I said before, you should also consider intensity and variance when designing an effective cardio training plan.  In my next post, I will detail three different types of intensity training that you can incorporate into your plan, I’ll describe what I mean by the word variance and how you can use it to get better and more individualized fitness results, and I will give you an example of how I helped one client go from struggling to walk uphill three minutes on a treadmill to finishing her first marathon.

The points I’ve listed here are the basic principles I use when designing training programs for my clients.  By using the combined information from this and next weeks post not only will you get better results, your routine will become more fun and interesting.


Outdoor, Treadmill & Incline Running Part 2

PART II: Incline Running on the Treadmill

Outdoor hill runs are a fun way to add variety to your workout routine, BUT if you are running indoors on a treadmill, incline running isn’t as fun.  Why do you ask…because it’s not only physically demanding, it’s also psychologically challenging (in other words no motivation to do it)!  It can take all the effort you have to get on the treadmill as it is, especially during the drabby dreary winter months in Michigan, adding inclines in on a regular basis can seem impossible on some days.

As you can imagine, I wouldn’t be writing about this topic unless there were some valuable benefits to including regular hill running in your routine.  First, you can accomplish the same energy expenditure achieved from high speed running while running on an incline at a lower speed.  This reduces overall impact on the joints while still giving the heart, lungs, and legs the same workout.


Speed    % Grade    METs       Speed     % Grade      METs
5.0 mph          0              8.7            5.0 mph        4.0             10.0
6.0 mph          0              10.2         5.0 mph         8.0             11.4
7.0 mph         0               11.7         5.0 mph         12.0           12.8
8.0 mph          0              13.3         6.0 mph          4.0             11.8
9.0  mph         0              14.8         6.0 mph          8.0             13.5
10.0 mph       0              16.3         6.0 mph         12.0            15.2

Remember METs is a measurement of work: 1 MET = the oxygen (energy) used by the body at rest (sitting and doing nothing). The harder your body works during the activity, the more oxygen is consumed and the higher the MET level.

As you can see from the chart, you can do the same amount of work running at 8.0 mph with 0% incline as running at 6.0 mph with 8% incline.  The benefit is of running at the slower speed is reduced impact on the joints and a different type of stress on the muscles, tendons, ligaments, and bones.

Not only does adding inclines to your workout reduced impact on joints, it also causes an overall improvement in sprinting ability on flat ground.  Sprint hill running is often used in traditional speed training programs to help sprinters increase stride length, speed-strength and ground force production.  Uphill sprinting is especially used to improve the acceleration phase of a sprint race (coming out of the start).[1]

Despite the mental and physical challenge of incline treadmill running, it’s worth it to give it a shot.  Here is an example run that I recommend for clients when they are first starting out.  If you haven’t been running on a regular basis you should try this at a walking speed and then slowly increase speed in order to be able to sustain this workout.

During this workout you keep the speed constant and manipulate the incline each minute for 20 total minutes.  Below is an example of a workout you could do.

Constant speed: 5.0 mph
Min 1: 0% grade
Min 2: 3% grade
Min 3: 6% grade
Min 4: 9% grade
Min 5: 3.0 mph walk, 0% grade

1.  NSCA’s Essentials of Personal Training, 2nd Edition; Coburn & Malek; © 2012

Is It Possible To Burn Fat in Four Minutes?

Note: This is an old post from the archives that I felt was worth reminding people about…learn & enjoy!

Not long ago, one of my friends told me about guerrilla cardio as his favorite fat burning cardio workout. Have you heard of it? It’s an ultra-intense cardiovascular workout based on a study done by Dr. Izumi Tabata, Ph.D..

Dr. Tabata, a researcher at the institute of Health & Nutrition in Tokyo, Japan, conducted a study compairing cardiovascular endurance training vs. high intensity cardiovascular training. In Tabata’s study, one group did a full 60 minutes of moderate-intensity exercise 5 days per week. Group two also trained 5 days a week, but performed up to eight 20-second sprints of high-intensity cycling with a 10-second rest (pedaling at a slower rate) in between [1]. They performed these sprints between warm-up and cool-down periods.

Tabata found that group 2 athletes (on the high-intensity program), got fitter faster than group 1 athletes who focused on endurance training despite the large difference in time spent working out (each day group 1 did 60 minutes & group 2 did 4 minutes). After this study was released, Muscle Media magazine published an article in October 2001 entitled: Guerrilla Cardio, which suggested a cardio program based on these findings.

Guerrilla Cardio

Minutes 1-4: Warm-up 50% perceived exertion

Minutes 5-8: Sprint- for 20 seconds; Rest- 10 seconds; Repeat

Minutes 9-12: Cool-down at 50% perceived exertion

Are you wondering how 4 minutes of exercise can burn more than 60 minutes? At first glance it doesn’t make any sense at all! But remember, the true benefit of high intensity interval training (HIIT) comes from the calories burned after the workout is complete. Intense exercise boosts oxygen consumption (called excess post-exercise consumption, or EPOC for short) and calorie expenditure after exercise to a greater extent than moderate-intensity activity.

Guerrilla cardio is an extremely challenging cardiovascular program that will burn fat & if you really go all out, you will be exhausted at the end of this workout.

This protocol does have some limitations when it comes to incorporating it into a fitness routine. The cardio session really only contains 4 minutes of actual challenging exercise and EPOC is tied to both exercise intensity (how hard you work) and exercise duration (how long you work for) [2]. If you are only exercising for 4 minutes, no matter how instense, there is a limit to the number of calories (and therefore fat) you can burn in that short period of time.

Remember that losing body fat comes down to burning more calories than you consume, period. You have the option of doing that in a variety of ways, some more effective and more efficient than others.

Your ultimate goal should be to adopt habits that enable you to maintain a fitness as a lifestyle, and that may or may not include HIIT or guerrilla cardio. Maintaining a long term program ultimately depends on what style of workout enjoy, what challenges you, and how much time you have.

If you are running short on time at the gym, the guerrilla cardio program will give you a kick butt workout in no time flat. A total of 35 minutes to spent at the gym could include 12 minutes of guerrilla cardio and 23 minutes of focused resistance training. You’ll have burned calories, maximized your time, and you will also be reassured that you’re getting the benefit of post workout calories burned (via EPOC, recovery, and subsequent muscle tissue growth).

My advice is to add guerrilla cardio to your repertoire of training methods. Use it as another fat burning tool, especially when you are short on time. If you would like to learn how to incorporate the guerrilla technique as well as others into your cardio training plan, let me know by emailing jes@jesreynolds.com and we can set up a training session or get you started with a training calendar. Good Luck!


1. Tabata I, Nishimura K, Kouzaki M, Hirai Y, Ogita F, Miyachi M, Yamamoto K (1996). Effects of moderate-intensity endurance and high-intensity intermittent training on anaerobic capacity and VO2max. Medicine and Science in Sports and Exercise, 28, 1327-1330

2. Bahr, R., Gronnerod, O., & Sejersted, O.M. (1992). Effect of supramaximal exercise on excess postexercise O2 consumption. Medicine and Science in Sports and Exercise, 24, 66-71