Matters of the heart

"What should my heart rate be when I exercise?"
"Is it safe that my heart rate shoots right up to 160 when I run?"
"My heart rate goes out of the 'fat burning zone' is that right?"

All of these are common questions I'm asked by clients just starting out with exercise as well as those who've tempted to dip their toe in the water but aren't really sure where to progress from there.

Our heart is a wondrous and complex organ; essential to sustaining life, it's quite right that we worry whether we're looking after it as well as we should be.

Thankfully, the answers to any worries are that if you're exercising, you're taking the right steps. Ignoring any medical conditions which prevent otherwise[1], exercise has AMAZING benefits for your heart and if you aren't already doing activities that get your heart racing in a day - no, not those ones... seriously, dirty minds!... then you should start now.

So, let's address those questions head on:

What should my heart rate be when I exercise?

There is a quick and easy calculation which gives a general guideline of what your max heart rate should be: 220 - your age. So, my max heart rate is: 220 - 38 = 182.
Depending on what you're looking to achieve, will depend on where you want your heart rate whilst you're working out. Looking to run a marathon? Then you want your heart rate to sit at around a steady 60% of max; want to lose body fat? Then you want your heart rate to spend short bursts at around 75-80% of max. Of course, the harder you're working the heart, the less able you are to maintain that level for a long period of time, so this will also dictate the type of exercise you are doing - long, slow and steady vs short, fast, high intensity.
To go back to my example, if I wanted to achieve a heart rate of 75-80%, I'd want to be getting my heart rate up between 136-157.

The thing to remember though is this is just a general guide and in reality, during training sessions, my heart rate regularly hits up between 185-190 for short bursts. Here's a visual example from my Fitbit; as you can see the average heart rate is 154 so within my target zone for the session as a whole.

Fitbit heart rate graph

Is it safe that my heart rate shoots right up to 160 when I run?

Short answer... yes.

But you should warm up first, and you should gradually build your heart rate up in the warm up first. So, no going all out as soon as you start. Begin with a brisk walk or a light jog, get the joints moving, raise your heart rate a little bit and ease yourself into it. Once you're warmed up and the oxygen is pumping nicely round your body, there's no reason why you can't ramp it up and go for an all out sprint (or bear crawl!) to get your heart really racing.

My heart rate goes out of the 'fat burning zone' is this right?

With the rise of wearable fitness tech, phrases such as the 'fat burning zone' have become much more common place. The key thing you need to know is that this zone is (ironically) not where you want to be if you actually want to torch body fat. In fact, the time your body is most efficiently in the fat burning zone is when you're sleeping! Even more reason to get that shut-eye right?!

The name comes from the fact that your body burns fat as it's main fuel source when there's no need for it to turn to anything else. It's during high intensity exercise that it needs to turn to alternative fuel for energy. On the surface then, it seems as though we'd be better keeping things low and steady in order to keep burning fat. However, when you train at a higher intensity, it puts your body into an oxygen debt. Once you've finished exercising, your body has to recuperate this debt and will therefore continue consuming energy at a higher rate even when you've stopped. Amazing right?!

In short...

Exercise of any form is good for you. NHS guidelines recommend a combination of strength training and cardio as the best way to maintain your health and fitness and there are so many benefits to getting your heart racing daily that I can't encourage you enough.

If you're not sure where to start, have a read of my beginners kickstart post here. Remember, you'll never regret what you started, but there's every chance you'll regret the 'should haves' and 'if onlys'.

Looking for some guidance, motivation or support? That's where I can help. I LOVE supporting people on their fitness journey and passionate about helping you to find that spark and kindle it in to something more.

Give me a shout on my Facebook page, from me a message or call me for a quick chat on 07790956673 and spark your fitness journey today.


  1. I'm not medically trained and if you have a heart condition, you need to talk to someone who is and the chances are you are already well informed on what you should and shouldn't do - ↩︎