Know your numbers for HiiT weight training

How hard should you exercise when doing HIIT weight training?

There are three main parts to exercising – intensity, duration and frequency. To improve your performance and fitness level – keep these three things in mind. They go a long way in enhancing the benefits you get from exercising . . . . especially when doing HIIT training.

High intensity interval training requires you to ramp up the intensity. Let’s look at this first and how to measure it and I’ll talk about duration and frequency in a future post.

Intensity of an activity is determined by how much effort you put into it.

How do you measure intensity? and How does it apply to HIIT weight training?

If you are starting a HIIT weight training session for the first time then you want to start at a low intensity and build from there. Start at an intensity that will allow you to do no more than 12 repetitions per set for specific exercises . . . .  and also keep your heart rate low when doing cardio.

Do this for a period of time such as a month or six weeks then give yourself a rest period of ten days before ramping it up. As your fitness level improve you can increase the intensity. Set daily, weekly and end goals.

Know your heart rate numbers

You can measure the intensity of an exercise by first calculating maximum heart rate (MHR).

Lots of formulas have been developed for calculating MHR. The one most often used is to subtract your age from 220. This has been determined to be a good approximation of our maximum heart rate. It is used by manufacturers of fitness equipment to calibrate heart rate zone on many of their machines. So for example, if you are 35 years old your max heart rate would be 220-35 or 185. 

Low to moderate intensity would be 60% – 80 % of your maximum heart rate (or approx. 110 in the example above). High intensity would be 85 % and over.

Your resting heart rate

To determine how hard you should be exercising you will need to know your resting heart rate (RHR). You can find your RHR by checking your pulse first thing in the morning, before any activity. To do this, use the index and middle fingers of one hand to feel your pulse on your opposite wrist. Count the number of beats for 15 seconds and multiply by four to get your heart rate for one minute. This is your resting heart rate.

Your target heart rate

To get the greatest health benefits from your workout, you must elevate your heartbeat rate to a certain level – normally referred to as your target heart rate (THR). (See below for a couple target heart rate formulas).

Exercising at your target heart rate will help to improve cardiovascular health, stabilize blood glucose, reduce body fat and boost endurance. For HIIT weight training you need to increase your target heart rate for short periods of time and return to a lower intensity for a brief rest before ramping it up again.

Caution: If your heart rate climbs above normal or your resting heart rate rises very quickly you need to stop or proceed with caution. At your earliest you should consult with your doctor and follow her advice on how to proceed.  Heart attacks can occur if your rate gets too high and blood pressure is too low. 

Training intensity should range from 60% to 90% of adjusted maximum heart rate. If you’re just beginning an exercise program or you want to concentrate on burning fat, then you should work at around 60 to 80% . . . with the eventual goal of steadily increasing to a moderate or higher rate of 85 to 90%.

Again for HIIT weight training you are maintaining a higher rate for short bursts and little rest. I aim for 8 intervals when I am doing HIIT.

Target Heart Rate calculations

There are two formulas commonly used for checking your target heart rate. Both are based on a maximum heart rate (MHR) of 220.

1.)  Age based formula:

MHR – Age x (Percentage of intensity) = Target Heart Rate (THR)

For example, to check the target heart rate of a 50-year-old exercising at an intensity of 60 %:

220 – age = maximum heart rate in beats per minute

220 – 50 = 170 beats per minute

170 x 60% = 102 beats per minute

A target heart rate of 102 beats per minute should be the rate at which a beginner who is age 50 be working towards. Try to figure out your target heart rate based on the above formula.

2.)   Karvonen heart rate formula

A more accurate formula for checking target heart rate is the Karvonen heart rate formula (developed by Dr Karvonen). It is more personalized than the standard aged based formula:

Heart Rate Reserve x Intensity + Resting Heart Rate = THR

Resting Heart Rate, as pointed out earlier, is the rate at which your heart beats at full rest. It is recommended that this rate be taken before getting out of bed, counting the pulse for a full 60 seconds, 3 mornings in a row and averaging the counts. Remember to use your index and middle fingers to find your pulse on your wrist (don’t use your thumb).

Heart Rate Reserve (HRR) is how much your heart rate would have to climb to reach your maximal heart rate:

(HRR) = maximal heart-rate – resting heart-rate

Let’s use this formula to calculate the Target Heart Rate of a 45-year-old man who has an average resting heart rate of 62 beats per minute. If he exercised at an intensity of 70 percent of maximum heart rate his target heart rate would be 141 beats per minute.

220 – 45=175 (Maximal heart rate)

175 – 62 = 113 (Heart rate reserve)

113 x 70% + 62 = 141 (Target heart rate)

Try calculating your target heart rate using the Karvonen formula.

Use these tools to fine tune your HIIT weight training program and reap the benefits of a healthier you.  Hope you enjoyed this post. I would love to hear your comments.