Final answer:
The target heart rate during exercise is calculated using the formula: 220 minus the person's age to find the maximum heart rate, then 50-85% of that number depending on exercise intensity. For strenuous exercise, time per beat in seconds can be calculated by dividing 60 by the heart rate in bpm.
Step-by-step explanation:
To determine a client's target heart rate during exercise, the most commonly used formula involves the maximum heart rate (MHR). The MHR can be estimated with the formula: 220 minus the individual's age. To then find the target heart rate, you would calculate 50-85% of the MHR depending on the intensity of exercise. For example, if you are 40 years old, your estimated MHR would be 220 - 40 = 180 beats per minute (bpm). For moderate-intensity exercise, you might aim for 50-70% of the MHR, which is 90-126 bpm for a 40-year-old individual.
Another aspect to consider is the heart rate during strenuous exercise. If the heart rate is 150 bpm, the time per beat in seconds is found by taking 60 seconds (as there are 60 seconds in a minute) and dividing it by the bpm. The calculation would then be 60 / 150, giving the time per beat as 0.4 seconds.
In terms of cardiac output (CO), during exercise, heart rate (HR) and stroke volume (SV), which is the quantity of blood ejected by each heartbeat, both increase. This elevates CO significantly. For instance, an increase in HR to 150 bpm and SV to 130 mL would boost CO to roughly 19.5 liters per minute, a noteworthy rise from the resting rate.