Write an exercise Rx to improve patients' cardiorespiratory fitness
Assessing physical activity is an opportunity to encourage lifestyle-based tactics for reducing cardiovascular risk. These handy tables serve as practical guides.
PRACTICE RECOMMENDATIONS
› Encourage children and adolescents (6 to 17 years of age) to engage in 60 min of moderate-to-vigorous physical activity, including aerobic, muscle-strengthening, and bone-strengthening endeavors on most, if not all, days of the week. A
› Encourage adults to perform approximately 150 to 300 min of moderate or 75 to 150 min of vigorous physical activity (or an equivalent combination) per week, along with moderate-intensity muscle-strengthening activities on ≥ 2 days per week. A
› Counsel patients that even a small (eg, 1-2 metabolic equivalents) increase in cardiorespiratory fitness is associated with a 10% to 30% lower rate of adverse events. A
Strength of recommendation (SOR)
A Good-quality patient-oriented evidence
B Inconsistent or limited-quality patient-oriented evidence
C Consensus, usual practice, opinion, disease-oriented evidence, case series
Using this framework, you can help patients realize intrinsic motivation that can facilitate progression through each stage, utilizing techniques such as motivational interviewing—so-called change talk—to increase self-efficacy.14TABLE 115 provides examples of motivational interviewing techniques that can be used during a patient encounter to improve health behaviors, such as physical activity.
Writing the exercise prescription
A patient who wants to increase their level of physical activity should be offered a formal exercise prescription, which has been shown to increase the level of physical activity, particularly in older patients. In fact, a study conducted in Spain in the practices of family physicians found that older patients who received a physical activity prescription increased their activity by 131 minutes per week; and compared to control patients, they doubled the minutes per week devoted to moderate or vigorous physical activity.16
FITT-VP. The basics of a cardiovascular exercise prescription can be found in the FITT-VP (Frequency, Intensity, Time, Type, Volume, and [monitoring of] Progression) framework (TABLE 217-19). For most patients, this model includes 3 to 5 days per week of moderate-to-vigorous physical activity for 30 to 60 minutes per session. For patients with established chronic disease, physical activity provides health benefits but might require modification. Disease-specific patient handouts for exercise can be downloaded, at no cost, through the American College of Sports Medicine (ACSM) “Exercise Is Medicine” program, which can be found at: www.exerciseismedicine.org/support_page.php/rx-for-health-series.
Determining intensity level. Although CPET is the gold standard for determining a patient’s target intensity level, such a test might be impracticable for a given patient. Surrogate markers of target intensity level can be obtained by measuring maximum HR (HRmax), using a well-known equation20:
HRmax = 220 – age
which is then multiplied by intensity range:
- light: 30%-39%
- moderate: 40%-59%
- vigorous: 60%-89%
or, more preferably, by calculating the HR training zone while accounting for HR at rest (HRrest). This is accomplished by calculating the HR reserve (HRR) (ie, HRR = HRmax – HRrest) and then calculating the target heart rate (THR)21:
THR = [HRR × %intensity] + HRrest
Continue to: The THR calculation...
