Exercise intensity and heart rate

Exercise Intensity

Exercise intensity refers to how hard the body is working during physical activity. It can be measured objectively and subjectively.
Objective ways of assessing intensity include heart rate and VO2 max (maximum oxygen consumption).
Subjective measures include the Rate of Perceived Exertion (RPE), which involves rating how hard one feels they are exercising.
Exercise intensity can be categorised into low, moderate, and high intensity.

Heart Rate and Exercise Intensity

Heart rate is a common, objective way to measure the intensity of a workout.
The heart rate increases in a linear relationship with increasing exercise intensity.
Resting heart rate (RHR) is the heart rate measured when the body is at rest. An average RHR for a healthy adult may range from 60-100 beats per minute (bpm).
Maximum heart rate (MHR) can be estimated by subtracting your age from 220. This is a general formula and individual differences should be taken into account.
Using percentages of your MHR, exercise intensity can be divided into different heart rate zones. These are recovery (60-70% MHR), aerobic (70-80% MHR), anaerobic (80-90% MHR) and maximum (90-100% MHR).
The heart rate zone is used to guide workout intensity. To improve cardiovascular fitness for example, it would be beneficial to train in the aerobic heart rate zone.

The Role of Heart Rate in Exercise

Monitoring heart rate during exercise can ensure that an individual is exercising within the desired intensity zone, which aligns with their fitness goals.
Knowing your heart rate can also be used to avoid under or over exertion, helping to optimise workouts and reduce the risk of injury.
A decrease in resting heart rate over time can indicate an improvement in cardiovascular fitness.

Factors Affecting Heart Rate

Factors that can affect heart rate include age, fitness levels, medical conditions, and the use of certain medications.
Physical factors such as the temperature, altitude, hydration levels, and diet can also influence heart rate.
Emotional factors such as stress and anxiety can also lead to an increased heart rate.

Training and Heart Rate

For endurance athletes, a common training method is heart rate-based training where training zones are determined by heart rate.
Interval training, where periods of high intensity are followed by recovery periods, can also be guided by heart rate measurements.
Over time, regular physical training can lead to a reduction in both resting heart rate and heart rate during exercise at a given intensity, reflecting an improvement in fitness level.