Being active raises your heart rate, or the number of times your heart beats in a minute. Everyone's fitness level is different, so working out your individual target heart rate (THR) is important to ensure you exercise within safe limits and achieve the best results. If you're generally healthy, experts recommend you aim for a THR that’s within 50% to 75% of your maximum heart rate. There are online tools that can help you determine your personal target rate.

Your maximum heart rate depends on your age and is the fastest speed your heart can beat when you're exercising. As with your target heart rate, it’s an estimate. Your maximum can be calculated by using the number 220 and deducting your age. So, if you’re 42, you take away 42 from 220 to arrive at 178bpm (beats per minute).

Check your pulse regularly when you’re working out. If you feel dizzy or you are struggling to breathe or talk, that's a sign you are probably doing too much. Slow down if you experience these symptoms, as you may be doing more harm than good to your heart.

It's possible to strain your heart if you push your heart rate over 90% of its maximum capability. Gradually building up your fitness with regular exercise is smarter as you can strengthen your heart and get fitter over time. If you have a history of heart problems, or are on heart medication, you’ll need to check with your GP before embarking on any new fitness routine.

You can check your pulse manually as you exercise, but it may be easier to buy a heart rate monitor that does it for you. There are many portable monitors available as well as exercise machines with built-in heart sensors that can track your beats per minute (BPM). These tools can help you identify how hard you're exercising and help you pace yourself. Some portable monitors are cheap and basic, while more expensive monitors include features that help you track how many calories you've burned and whether you've met your individual goal.

Unless your GP tells you otherwise, due to a medical condition, there’s no need to check your heart rate every minute during exercise. Depending on how old you are and your personal goals, it's sensible to check your BPM about every 5 to 10 minutes. Checking your pulse rate straight after you exercise can help keep track of your level of fitness. Also remember to include a warm up period and cooling down time to be safe and decrease your risk of injury.

Interval training involves switching between bursts of high intensity activity and low intensity activity. So, if you're running, it means doing fast sprints alternated with slower jogging. This start and stop pattern allows your body recovery time. You can also monitor your heart rate during each interval. During low to moderate periods, your goal should be about half of your maximum heart rate. During vigorous exercise, aim for 70% to 85% of your maximum rate.

By exercising, you are strengthening your heart muscle. It means it doesn't have to work as hard to pump blood around your body. This lowers your resting heart rate. The average resting heart rate is between 60 – 100 bpm. If you're a fit athlete, your resting rate may be 40 – 60 bpm or lower. A lower resting heart rate is associated with people who live longer, so head to the gym or walk, run  or swim to look after your heart and your overall health.