A Beginner’s Overview To H.I.I.T. Workouts


Last time I covered about how ineffective and time consuming doing hours of cardio is.

It’s easy to get on the machine, check out watching a tv show at the gym, and when you’re finished check off that box that says you’ve completed your workout for the day.

For many even getting to the gym is an accomplishment!

But for those who walk out still not being as lean they want with all the hours they’ve put in they need a different strategy.

I’m not trying to demonize bouts of long cardio. There is a time and place for it.

But if you want to lose weight and burn fat to get that hotter lean look FAST steady state cardio is not going to get you there.

Doing some form of cardio is important if you have a specific bodyfat or bodytype in mind you want to achieve. You will struggle to reach under 20% bodyfat if you’re a women and below 10% if you’re a man if you don’t include some form of cardio in your workouts.

In reality here are some ballpark bodyfat measurements for women to aim for if you’d like a specific body,

Above 30% – There is something to work on. You really want to get leaner than 30% for both looks and for your health.

At 25% – This is a healthy amount of bodyfat to have. This is where I recommend my clients get to for maintenance. It’s not to crazy hard to reach this stage with the right diet and exercise plan.

At 23% – The female bodies you admire at the gym where they look lean and toned are around this percent of bodyfat. You’re really in shape at this bodyfat.

At 21% – You’re rockin’ your clothes and look great in a bikini. It is at this percent of bodyfat that most women are able to do 3 pullups.

At 19% or below – You’ve won the bodyfat lottery. You’re lean, you’re in shape, and you look amazing in whatever you wear. Most female Olympic athletes are around this range.

(Photo Credit: BodyNSoil)

If you’re a man, here are your ballpark bodyfat measurements,

Above 22% – You really want to work on lowering your bodyfat. The health and the body you desire is below this bodyfat percentage.

At 17% – This is a healthy amount of bodyfat for males.

At 14% – You’re ahead of 80% American males. You’re lean and you’re in great shape.

At 12% – You look great in whatever clothes you wear and you should be happy taking off your shirt at the beach.

At 9% – This is where most men will have a flat stomach and start revealing their six pack abs.

(Photo Credit: BodyNSoil)

So what are the alternatives to slogging away on the treadmill for hours at a time like majority of the gym users?

It’s called HIIT aka High Intensity Interval Training.

Why does 15 min HIIT workouts beat hours of cardio?

HIIT is great If you are short on time and can tolerate the intense brief moments pain. These workouts will make you burn, torch your fat, and skyrocket your heart rate. The phenomenal benefits of HIIT make the pain and discomfort so worth it.

(1) Make me a lean, fat burning machine

In multiple studies done by university scientists they’ve concluded that HIIT cardio style workouts are more effective at reducing abdominal fat more than other types of cardio.

For example in this study they found that you burn 2X as much as fat in 9 minutes a week of HIIT workouts than you do in 3 hours of endurance cardio.

Talk about better and faster results in less than half the time!

(2) Food has less power over me

A common by-product result of doing long bouts of cardio is the hunger many cardio users experience after their endurance workouts. Most end up eating back the calories they burned and lots more defeating the purpose of their workout.

Research has shown that HIIT style cardio changes the way the brain regulates appetite and helps you feel fuller after anything you’ve eaten.

When you’re trying to lean out every calorie counts and anything that helps curb your appetite works in your favor.

(3) Get me to my fat loss goals FASTER

When you are a fat loss journey your #1 goal should be to preserve lean muscle tissue because it helps you to burn more calories at rest. Hours of cardio and eating a low calorie diet can only get you so far before you start losing muscle.

If you want to get lean which is under ~20% for women and under ~10% for men you need to do cardio to boost your calorie burn while preserving muscle at the same time. Excess cardio every week will not only burn fat but also burn away precious muscle which is why HIIT cardio is the choice of athletes and figure competitors.

HIIT me now

So how can I design my own fat torching workout if I only have 15 minutes to workout?

The overall structure of a HIIT workout is alternating between periods of high and low intensity exercising. We’re looking at brief moments of high intense periods of work alternated with either rest or almost rest states in between.

How intense are we looking at?

During HIIT workouts you want to achieve 90% of your maximum oxygen capacity input otherwise known as your Vmax.

You want your breathing to be labored and feel like you cannot get enough oxygen to recover.

A good way to look at it is like sprinting around the track.

When you are exercising at high intensity you are full out sprinting then during low intensity you are simply walking or pacing to cool off.

High and low intensity periods of exercise keep alternating until you complete the length of your HIIT workout.

When I have my clients do any type of HIIT workouts I like to use a 1-10 scale to measure their level of intensity.

A 1 on the scale means you’re sitting on the coach watching Game of Thrones. Relaxed, no exertion at all. Eating popcorn is all the movement you’re doing.

A 10 on the scale means you’re Usain Bolt running for the Olympic Gold and setting a new world record.

When you’re doing a HIIT workout you want to be working around level 8 or 9 to get the benefits. So not the gold medal but you definitely want to be on the podium with a silver.

HIIT workouts are fast, intense, and hard but short.

How long is a HIIT interval?

That depends on your Vmax which is your maximum oxygen input, the maximum amount of oxygen you can breathe in at any given time.

Reaching your Vmax is labored breathing and feels like you cannot suck in enough air to recover.

Like how you would feel after running several San Francisco blocks at full speed with a heavy bag to catch the 38 Muni line so you can go home.

During the high intensity part of the exercise you want to reach at minimum 90% of your Vmax capacity during the entire duration of the exercise. You want to be breathing hard within 10 to 15 seconds of starting. Remember you want to step on the Olympic metal podium with a silver medal around your neck.

You’re not slowly ramping up the intensity, you are reaching 100% intense from the start.

This is how hard you want to push yourself and for how long is based on your Tmax.

Your Tmax is the length of time you can exercise at 90% of your Vmax.

Is it 2 minutes?

1 minute?

45 seconds?

However long it is you want to exercise at high intensity for 50% of your Tmax time.

If you can keep up the intensity for 2 minutes than your intervals should be 1 minute long at 90% of your Vmax. If it’s only 30 seconds then your intervals should be 15 seconds long.

I find that either bicycling, the stairmaster, the treadmill, or the rowing machine are great pieces of cardio equipment to do HIIT workouts on.

If you’re outside, doing hill sprints is excellent as well and in San Francisco there is no shortage of hills and stairways plus Vitamin D. 🙂

What about my rest?

As far as rest goes you want to start off with a rest to work ratio of 2:1. This means if you’re exercising for 1 minute you want to actively rest for 2 minutes before you start again.

Active rest means you’re constantly moving not standing or sitting down. This helps you to recover quicker and adapt to the training effect more effectively.

When you recover faster you can shorten your rest periods to 1:1.

How long of a HIIT workout and how often?

HIIT workouts are intense which means you can get all the benefits in about 15 to 20 minutes.

Do a 3 to 5 minute warm up then begin your HIIT interval cycles for 15 to 20 minutes. Depending on your goals and where you are in your fat loss journey I find that 3-4 times a week is plenty.

To Sum It Up

Here’s why HIIT workouts need to be included in your exercise routine,

(1) HIIT workouts are fat torchers that preserve muscle and suppress appetite. You can burn 2X as fat in 9 minutes/wk compared to 3 hrs of moderate cardio.

(2) You need cardio to reach certain levels of leaness. Under 20% for women and under 10% for men.

(3) Start with a work rest ratio of 2:1. Alternate intervals where you work at 90% of your maximum oxygen capacity and rest 2X.

Candace Rhodes
I’m a NSCA-Certified Personal Trainer, hold a MS in Biochemistry, and have over a decade of experience in the biotech industry. I specialize in cutting through the noise and fads to help females lose weight, specifically the last 10-15lbs, all without crazy restrictive diets, endless hours of training. I help make it sustainable, fun, and effective, boosting their morale and helping them look and feel amazing in a body they love!