Prescribing Exercise Prescriptions that FITT for Adults with Elevated Blood Pressure and Cholesterol in the Middle of the Cardiovascular Disease Risk Spectrum

The American Heart Association (AHA) and American College of Cardiology (ACC) recently released new guidelines for the prevention, treatment, and management of high blood pressure¹ and cholesterol.² In both sets of guidelines, lifestyle interventions only are recommended for adults at low cardiovascular disease (CVD) risk, and they are recommended in combination with pharmacological treatment for adults at high CVD risk (see Gibbs et al. Figure 1). For adults in the middle of the spectrum of CVD risk- the mild-moderate CVD risk groups- lifestyle-only approaches are recommended as the first line of therapy. The mild-moderate CVD risk groups are defined as adults with elevated BP or Stage 1 Hypertension and an atherosclerotic CVD (ASCVD) risk score <10% and/or adults 40-75 years and with low density lipoprotein cholesterol (LDL-C) 70-189 mg/dL, an ASCVD risk score <7.5%, and a low burden of other CVD risk factors. The number of Americans meeting the BP (21%) and cholesterol (28%) definitions of mild-moderate CVD risk is not trivial with some overlap between the two groups.

The lifestyle treatment options in the AHA/ACC guidelines include physical activity, weight loss, dietary modification, smoking, and alcohol moderation. A primary purpose of the AHA Scientific Statement by Gibbs and colleagues was to describe the recommendations, average effects, and special considerations when prescribing physical activity to mild-moderate CVD risk patients.³ Therefore, the focus on this Commentary will be on exercise prescription recommendations for patients with elevated BP and cholesterol who are at mild-moderate CVD risk. The authors of this AHA Scientific Statement recommended the federal Physical Activity Guidelines for Americans for clinical use among patients with chronic diseases and health conditions that include adults with elevated BP and cholesterol. The federal guidelines are as follows: 150-300 minutes per week of moderate-intensity or 75-150 minutes of vigorous-intensity or an equivalent combination of the two of aerobic exercise plus two or more times per week of moderate-to-vigorous intensity resistance exercise involving all muscle groups.⁴ While the authors’ stated the rationale for this approach was that it is founded on the most extensive, expert review of physical activity and health outcomes available⁵, these physical activity recommendations are not nuanced for the unique considerations in exercise prescription for patients with elevated BP and cholesterol that I will now elaborate on.

An exercise prescription is the process whereby an individualized physical activity program is designed using the Frequency (how often?), Intensity (how hard?), Time (how long?), and Type (what kind?) or the FITT principle of exercise prescription.⁶ Framing the exercise prescription by the FITT principle provides clinicians with more structured guidance on how to recommend exercise to their patients.⁷ The American College of Sports Medicine (ACSM) recently published 15 pronouncements on topics reviewed in the Physical Activity Guidelines Advisory Committee Scientific Report⁵ that provided the scientific foundation for the federal Physical Activity Guidelines of Americans⁴ that Gibbs and colleagues have recommended for clinical use among patients with elevated BP and cholesterol. The topic of one of these Pronouncements was, Physical Activity to Prevent and Treat Hypertension⁸, and ACSM followed this Pronouncement with a blog that contained the updated the exercise and hypertension recommendations of the College.⁹

The updated ACSM FITT exercise recommendations for adults with elevated BP are:

• Frequency- in most, preferably all days of the week due to the transient BP lowering effects that last for up to 24 hours after an exercise session;
• Intensity- Moderate, any intensity of exercise has been shown to lower BP, however, when weighing the risk-to-benefit ratio in this patient population emphasize moderate intensity;
• Time- >20 to 30 minutes per day to total >90 to >150 minutes per week of continuous or accumulated exercise of any duration; and
• Type- Emphasize aerobic or resistance exercise alone or combined due to recent evidence showing the BP lowering effects of exercise do not vary by exercise modality.^8,10-12

The updated ACSM FITT exercise prescription recommendations offer more exercise options in less time for adults with elevated BP that hopefully will translate to better exercise adherence for this patient population.

Gibbs and colleagues³ acknowledged the topic of physical activity and blood cholesterol was not covered in the Physical Activity Guidelines Advisory Committee Scientific Report⁵ so there was no ACSM Pronouncement written on this topic. The meta-analyses on the effects of exercise on the components of the blood lipid-lipoprotein profile cited by Gibbs et al.³ were older being published between 1993 to 2009 except Sarzynski et al.¹³, and they were not consistent. Our group has found that the more recently the meta-analysis is published, the higher the methodological quality score¹⁴, a finding that may also contribute to the inconsistencies in this literature. An important point made by Gibbs and colleagues is the influence of exercise on blood lipid-lipoproteins varies by the component of the lipid-lipoprotein profile, the modality, intensity, and volume of exercise, and whether the study population has elevated cholesterol or not, and if elevated, the level to which it is elevated or the floor effects of exercise. The ACSM exercise prescription for individuals with dyslipidemia resembles that for healthy adults, with an added focus on healthy weight maintenance.¹⁵ Accordingly, ACSM recommends adults with dyslipidemia to perform moderate-to-vigorous intensity aerobic exercise 30 to 60 minutes per day and upwards to 50 to 60 minutes per day to promote weight loss, with resistance exercise adjunct to the aerobic training program due to the minimal impact resistance exercise has on overall caloric expenditure.

Taylor and colleagues recently conducted a systematic review of randomized controlled trials (RCT) lasting ≥ 4 weeks investigating the effects of exercise on lipid-lipoproteins in adults ≥18 years that were published in English in a peer-reviewed journals indexed in PubMed from 2004 to July 1, 2014.¹⁶ Of the 910 potentially qualifying reports that emerged from the search, 15 RCTs and 26 meta-analyses, reviews and position stands were included. Taylor et al. concluded moderate intensity aerobic exercise training with a volume of 15-20 miles per week or caloric expenditure of 1200 to 2200 kcal per week was effective for increasing high density lipoprotein cholesterol (HDL-C) and reducing triglycerides (TG) with greater intensities and volume eliciting more favorable effects; while the research they reviewed suggested that resistance exercise may have a greater impact on reducing LDL-C than aerobic exercise training. These authors noted, however, aerobic exercise training appears to have little effect on HDL-C in men with low levels of HDL-C (< 40 mg/dL) which contrasts the floor effects of exercise seen with BP. Taylor et al.¹⁶ concluded combined aerobic and resistance exercise or concurrent exercise training may be the most prudent exercise prescription for adults with dyslipidemia because it augments HDL-C and lowers TG and LDL-C in the same individuals, although evidence was limited addressing exercise dose-response for concurrent exercise training and lipid-lipoprotein levels as was also noted by Gibbs et al.³

In conclusion, as recommended by Gibbs and colleagues, the federal Physical Activity Recommendations for Americans are warranted for clinical use among adults with chronic diseases and health conditions that include those with elevated BP and cholesterol who are at mild-moderate risk of CVD.^3-5 This Commentary takes the exercise recommendations a step further by emphasizing an individualized FITT exercise prescription that integrates evidence on the nuances of exercise prescription for adults with elevated BP and cholesterol to optimize the favorable effects of exercise among these mild-moderate CVD risk groups.