To work towards an answer, there are a few key questions that might prove useful here. Ask yourself, is your heart rate higher than normal? If so, then there could be a few explanations.

　　Illness can often drive up heart rate even if you're unaware that your body is fighting something. Fatigue and a lack of sleep can also mean a higher BPM than normal.

　　Dehydration can also elevate heart rate, as can anaemia (more common in female athletes) due to the body working harder to pump blood. By identifying the issue at play, a fairly easy solution is available for each of these factors.

　　However, what if the elevated heart rate is the norm? Two questions are key here. Firstly:

　　Is your heart rate high for you?

　　The equation ‘220 – age’ is still printed on equipment at my local gym as the way to work out HR max and therefore zones. However, this equation doesn’t accurately show what our hearts capacity is. It also doesn’t change as much as suggested over time.

　　Poor calculations like this might suggest a HR is ‘high’, when in fact your HR simply beats faster than other peoples at a given intensity. Track heart rate over time at different run paces to know what is normal for you.

　　Talk while you run

　　Secondly, many athletes run their ‘easy’ runs too hard. In these runs, conversation should be easy, you should be able to breathe only through your nose and the pace should feel sustainable and no harder than about 4/10.

　　If you think you're running too hard, then by running slower you'll become more aerobically efficient over time and your heart rate at a given pace will fall.

　　A few other factors could also be at play. If you're pregnant, have had caffeine, are stressed or over stimulated or have an overactive thyroid your heart rate might also be higher than usual.

　　If you've asked these questions and are satisfied that you're running slowly enough and there are no other factors at play, then maybe you just have a naturally high heart rate.