As a fitness professional living in NYC for the past 20 years and working with the city’s busiest, time-crunched professionals, full time parents and often those juggling both career and family, you can imagine how happy I am that a brilliant scientist from the University of Copenhagen decided to do a little study1  that proved you could not only get the same, but better results by working out less time at a higher intensity-practicing High Intensity Interval Training.   So if you want to take your fat loss and overall fitness to the next level—and spend less time in the gym—then high intensity interval training (also known as HIIT) might be for you. 

Note, I didn’t say it would be easier, just that it would take less time. :)  So before giving you all the details, it’s key to know that because the HIIT approach to cardio exercise is very physically demanding, it isn’t for everyone.   If you have any cardiovascular problems or other health concerns that limit your ability to exercise at very intense levels, HIIT may not be for you—at least for now.   If in doubt about whether it's safe for you, check in with your medical professional before trying HIIT.
 
WHAT IS HIGH INTENSITY INTERVAL TRAINING (HIIT)?  
HIIT is an enhanced form of interval training, an exercise strategy, alternating periods of short intervals of maximum* intensity  anaerobic exercise  with longer intervals of low to moderate** intensity recovery periods.  

For example:

• Warm up for three to five minutes
• Then sprint as hard as you can for 30 seconds
• Then recover  for 90 seconds

...and repeat

 The key is that your recovery period needs to be three times (3x) longer than your sprint period. The goal is to work yourself up to 8 intervals over time. Because it involves briefly pushing yourself beyond the upper end of your aerobic exercise zone, it offers you several advantages that traditional steady-state exercise (when your heart rate remains within your aerobic zone) can’t provide.

*Maximum intensity = a 9 or 10 on a 1-10 scale, with 10 being an all out  runnin’ for your life sprint. 
**Low to moderate = a 3 to 5 on the same scale. 

 Scroll to end of blog if you want to cut to the chase and get my recos, sample HIIT workouts and Intermittent Fasting Schedules!

THE STUDIES & BENEFITS OF HIIT
By Dr. Mercola

"Compelling and ever-mounting research shows that the ideal form of exercise is short bursts of high intensity exercise.

Not only does it beat conventional cardio as the most effective and efficient form of exercise, it also provides health benefits you simply cannot get from regular aerobics, such as a tremendous boost in human growth hormone (HGH), aka the “fitness hormone.”

One study published in the Journal of Obesity2 reported that 12 weeks of HIIT not only can result in significant reductions in total abdominal, trunk, and visceral fat, but also can give you significant increases in fat-free mass and aerobic power.

Other research published in the journal Cell Metabolism3 showed that when healthy but inactive people exercise intensely, even if the exercise is brief, it produces an immediate measurable change in their DNA.  To read more, click HERE. "


NET NET OF HIIT
By Fitness and Behavior Expert Dean Anderson

• HIIT trains and conditions both your anaerobic and aerobic energy systems.  
  
• HIIT increases the amount of calories you burn during your exercise session  
  
• HIIT causes metabolic adaptations that enable you to use more fat as fuel under a variety of conditions. This will improve your athletic endurance as well as your fat-burning potential.
  
• HIIT appears to limit muscle loss that can occur with weight loss, in comparison to traditional steady-state cardio exercise of longer duration.

INTERMITTENT FASTING & HOW IT RAMPS THE FAT BURNING:
By Dr. Mercola

“Is it a good idea to “starve” yourself just a little bit each day, or a couple of days a week? Mounting evidence indicates that yes, intermittent fasting (IF) could have a very beneficial impact on your health and longevity.

I believe it’s one of the most powerful interventions out there if you’re struggling with your weight and related health issues. One of the primary reasons for this is because it helps shift your body from burning sugar/carbs to burning fat as its primary fuel.

As discussed in the featured article,1 intermittent fasting is not about binge eating followed by starvation, or any other extreme form of dieting. Rather what we’re talking about here involves timing your meals to allow for regular periods of fasting.

I prefer daily intermittent fasting, but you could also fast a couple of days a week if you prefer, or every other day. There are many different variations.

To be effective, in the case of daily intermittent fasting, the length of your fast must be at least 16 hours. This means eating only between the hours of 11am until 7pm, as an example. Essentially, this equates to simply skipping breakfast, and making lunch your first meal of the day instead.” To read more, click HERE 


BENEFITS OF COMBINING HIIT AND INTERMITTENT FASTING:  

Several books published in the last couple years prove that working out in a fasted state (before your first meal of the day) shifts your body into an maximized fat-burning zone by  protecting your active muscle tissue and activating your sympathetic nervous system, responsive to both exertion and the absence of food. The Intermittent Fasting method is most effective and beneficial when a foundation of healthy eating (such as the Mind Body RE BOOT eating protocol) is already in place.  


NET NET OF HIIT & IF:  

HIIT and IF are the ultimate power couple when it comes to disposing of adipose tissue. To read more about this duo by Dr. Mercola click HERE  


MY RECOS-HOW TO INCORPORATE HIIT AND INTERMITTENT FASTING: 


1.  First and above all, eat a healthy balanced diet: lean, clean proteins, lots of green non- starchy veggies and juices. Avoid all processed and fried foods and the most common allergens or food triggers: dairy, gluten, sugar. 
Have your largest meal at lunch and eat a healthy, light dinner as early in the evening as possible. For example 4 ounces of low mercury fish or other clean protein and lots of non-starchy veggies. 

2.  Incorporate Intermittent Fasting as many days a week as you can. See my sample day HERE. 

3. Do 3 x 20-25 minute HIIT workouts per week, in the morning, optimally 30 minutes before breaking your fast.  See my sample HIIT workout HERE. Yes your fave Soul Cycle, Flywheel Sports and other high intensity group fitness classes or personal training workouts count as long as they incorporate at least 7 “sprints” followed by recovery periods. 

Remember to round out your exercise program with three, strong core workouts like my PATY’s and three good stretch or Yin Yoga  sessions each week

I recommend that because of the intensity of the workout that you do it no more than three times a week and best with at least one day in between each. Supplement your HIITS with at least three core workouts a week.


1. M. Rosenkilde, P. L. Auerbach, M. H. Reichkendler, T. Ploug, B. M. Stallknecht, A. Sjodin. Body fat loss and compensatory mechanisms in response to different doses of aerobic exercise – a randomized controlled trial in overweight sedentary males. AJP: Regulatory, Integrative and Comparative Physiology, 2012