Are you training hard enough?
by Bronwen de Klerk

A question I often get asked is:

'How do I know if I'm training hard enough in my cardio workouts?'

The answer is to use your training heart rate as an indicator of your cardio workout intensity. This can be measured manually by placing your index and middle finger on either the neck or wrist palpation points and counting the number of beats per minute, or you can use a heart rate monitor. The benefit of using a heart rate monitor is that you get continuous feedback on the intensity of your workout whilst you are training.

Target Training Heart Rate
So how do you know what heart rate to train at? You would need to take into consideration how long you have been following your cardio program for. The longer you have been training for, the higher the training heart rate you can aim to train at, and for a longer duration of time. The following is a good guide as to how to increase your training intensity if you are just starting out, training 3 times a week and building up intensity over 4 months ('%HRR' means 'Percentage of Heart Rate Reserve'. You use this percentage in the formula below):

When you first start to increase your target training heart rate, you don't have to spend all of your training time at that heart rate. You can spend 5 minutes at the new increased heart rate, then decrease the intensity for 2 minutes before increasing for another 5 minutes etc. Eventually you will be able to spend the whole duration of your training session at the new increased intensity. Just remember to always listen to what your body is telling you.

Use the following formula to calculate what heart rate you should be training at:

TTHR = RHR + [%HRR x ((220 - Age) - RHR)]

TTHR =Target Training Heart Rate
RHR = Resting Heart Rate

How to use the formula:

• Take your resting heart rate (RHR) - the best time to take this is before getting out of bed in the morning
• Subtract your age in years from 220 to get your estimated maximum heart rate (MHR)
• Subtract your resting heart rate (RHR) from your maximum heart rate (MHR)
• Multiply this number by the percentage heart rate reserve you are aiming to exercise at.
• Add this number to your resting heart rate to give you your target training heart rate (TTHR)

THR = 75 + [50% x ((220 - 35) - 75)]
THR = 75 + [50% x (185 - 75)]
THR = 75 + [50% x 110]
THR = 75 + 55
THR = 130 beats per minute

This means you should aim to train with a heart rate of 130 beats per minute for a duration of 10 minutes when first starting to train. (5 beats to either side of this number is also fine.)

Warming Up and Cooling Down
You would need to warm-up doing the same activity for at least 5 minutes before reaching your target training heart rate. I.e. if you are running, you will start off jogging at a slow pace for 5 minutes, gradually increasing your heart rate to your target heart rate. Once you are at your target heart rate, you will try and maintain this intensity for the specified duration. You would then cool down for 5 minutes, allowing your heart rate to decrease gradually, before stopping your training session.

Recalculating your Target Training Heart Rate
The fitter you get, the lower your resting heart rate (RHR) will be. You will therefore need to recalculate your target training heart rate (TTHR) every 4 weeks, taking into consideration your lower resting heart rate (RHR).

By using this method to work out the target intensity of your workout in conjunction with a heart rate monitor, you can ensure you always get the most out of each training session.