Determination of exercise intensity
If you’re new to exercise and looking to start a new training program, you may be wondering what intensity level is appropriate for your goals and fitness level. Many people are unsure what intensity levels are defined and avoid exercises labeled as vigorous intensity due to fear of injury or lack of ability. As a personal trainer and exercise physiologist, it’s my job to help explain these terms and concepts in a more understandable way. In this article, I’ll break down light, moderate, and vigorous intensity, so that you as a fitness person are more educated and comfortable with what you’re doing in your daily workouts. It is recommended that most healthy adults engage in a combination of moderate and vigorous exercise, while unfit individuals engage in light to moderate exercise. Intensity is individually based, which means that your intensity level is based on your physical abilities and is not generalized by the abilities of others. Ideally, you’d want a professional in the field to determine your intensity levels based on a guided fitness test, but I’ll provide information that will allow you to get an estimate without such resources. For this we will use what is known as the objective human resources reservation method. This method starts with HR reserve, which is defined as the difference between your resting heart rate and your maximum HR. Your HR reserve is then multiplied by the appropriate intensity percentage you are targeting, then your resting HR is added back together to get your target HR reserve. Below I have demonstrated the method for moderate intensity exercise for myself.
1) To find your estimated maximum HR, subtract your age from 220.
220-22= 198 bpm. My estimated maximum HR is 198 beats per minute.
2) To find your resting heart rate, wear a radial pulse or HR monitor. My HR at rest is 60 beats per minute. I will now subtract my resting HR from my estimated maximum heart rate to determine my heart rate reserve.
198 – 60 = 138 beats per minute.
3) Now I need to use the Heart Rate Reserve (HRR) and multiply it by the percentage equivalent to the intensity you intend to achieve.
A. Light intensity <50% HRR
b. Moderate Intensity 50-70% HRR
vs Vigorous Intensity 70%-85% HRR
In this case, I would like to exercise at a moderate intensity. So I’ll multiply my HRR by 50% to get my lowest HR value and then by 70% to get my highest HR value to stay within that moderate intensity range.
138 beats per minute X.50 = 69 beats per minute.
138 beats per minute X.70 = 96.6 beats per minute.
4) The last step in this process to get your final target HR reserve range is to add your resting HR back to the HR percentage. This allows the equation to consider your resting cardiovascular endurance level and adjust accordingly. Below I’ve demonstrated how to do it and found my target HRR range for moderate intensity exercise.
69 beats per minute + 60 beats per minute = 129 beats per minute
96.6 beats per minute + 60 beats per minute = 156.6 beats per minute.
Target HR range for moderate intensity = 129 bpm – 156.6 bpm.
Benefits of light intensity exercise
Light intensity exercise is very beneficial for older adults. It allows them to remain physically active when there may be physical limitations or health problems that prevent moderate or vigorous activity. Light intensity is considered to be below 50% of target heart rate reserve and provides many health benefits, especially for people who are out of shape. A study from Oregon State University, published in the American Journal of Health Promotion, showed a significant increase in the health of older people who participated in light physical activities such as walking. These individuals were less likely to develop chronic diseases and had lower body mass index measurements.
Benefits of moderate intensity exercise
Moderate intensity exercise is the most beneficial form of exercise. It produces a tremendous number of health benefits ranging from lower blood pressure, improved cholesterol, weight control, cancer prevention, and much more. A moderate intensity is recommended for all adults unless restricted by a physician. Moderate intensity is anything between 50% and 70% of your target HR reserve and can be achieved by doing many activities including brisk walking, leisurely bicycling, aqua aerobics, and dancing. There are a wide range of ways you can be physically active and reap the benefits of moderate intensity, but it starts when you take the first step.
Benefits of Vigorous Intensity Exercise
Vigorous-intensity exercise is recommended for adults who are usually physically active and with at least an average fitness level. Vigorous intensity is not powerlifting or Olympic-paced sprinting. Vigorous intensity activities include jogging, rowing, elliptical, speed dancing, and aerobics. The target HR reserve percentage is anything between 70% and 85%. It is recommended that if you have a history of health-related problems or are middle-aged, you get clearance from your doctor before engaging in vigorous activity. Vigorous intensity has benefits similar to moderate intensity, but it also carries an increased risk of injury. It is recommended that the average adult achieve a combination of moderate and vigorous intensity to achieve maximum benefits from exercise.
Now what?
In conclusion, you should know that intensity levels are important but they are not as intimidating as they sound. The ACSM recommends that a healthy adult get 30 to 60 minutes of moderate exercise or 20 to 60 minutes of vigorous exercise, or a combination of both, every day for ≥3 to 5 days a week. It is also recommended that if you only participate in moderate intensity, you do so 5 ≥ days per week and if you only participate in vigorous intensity, 3 ≥ days per week. Ask your doctor if you have any concerns about your current physical condition and your ability to perform vigorous-intensity exercise. I hope you can take what was mentioned above and use it as a resource on your path to optimal wellness.