User: Roslyn is 36 years of age, weighs 74 kg, is 165 cm tall, and has 35% body fat. Her father had a heart attack at age 68 and her brother had an angioplasty at age 40. Both are living and well. Her blood chemistry values measure total cholesterol at 195 mg% and HDL cholesterol at 42 mg%. Her fasting blood sugar is 105 mg%. Roslyn is sedentary and has engaged in no endurance training program since college. Brainstorm an appropriate exercise training program to help Roslyn improve her C-R (cardiorespiratory) fitness. Be sure to calculate a target heart rate range with corresponding RPE.
Assistant: We can prescribe an exercise program through the lens of FITT: frequency, intensity, time, and type. For frequency, we should aim for 3-5 days per week, with the higher the better the improvements for C-R fitness. As for intensity, we want to aim for 60-90% HRR (heart rate recovery), anywhere from 4-8 RPE (rate of perceived exertion). Since Roslyn is 36 years of age, her predicted maximum heart rate is 184bpm, and we are given that her RHR (resting heart rate) is 64bpm. Thus, we’re aiming for a target heart rate range of 136 BPM to 172 BPM. For time, the duration depends on intensity, but optimally, we want to be working out for at least 20 minutes and at most an hour. As for the type of exercise, we can assess the options that are available and feasible for Roslyn to perform, and choose between weight-bearing exercises (such as walking or jogging) and non-weight-bearing exercises such as swimming or rowing. Another thing to consider is that Roslyn is sedentary, and may need to slowly progress into a more intense workout. A sample exercise training program for Roslyn may first start with a moderate-intensity aerobic activity for 30 minutes a day, three times a week (Monday, Wednesday, and Friday). As she gets more acclimated to the exercise level, we want to progress to more vigorous exercise. According to David P. Swain, vigorous aerobic exercise may result in “substantially more benefits than moderate-intensity exercise”, which include but are not limited to greater improvements in aerobic fitness and greater reductions in coronary heart disease risk. Thus, we can add two more days of vigorous aerobic exercise for Roslyn, such as jogging for 20 minutes on Tuesdays and Thursdays. Another important aspect to consider is motivation, which we can help Roslyn maintain by switching up her forms of exercise to keep interest. For example, we can switch out jogging with cycling, or hiking hilly terrain.