FormalPara Key Points

Exercise is part of the management guidelines for the most prevalent chronic diseases treated in primary care.

The best exercise regimen (i.e. exercise type, intensity, duration, and frequency) is very similar across chronic diseases.

Elaborating and implementing a standardised, minimum exercise guideline in primary care for multimorbid patients may be an alternative to time-costly individualised exercise prescriptions.

1 Introduction

Physical activity (PA) and exercise are recognised as one of an individual’s vital signs [1] and are important factors for health promotion in overall healthy adults and several clinical populations [2–5]. Exercise, a subset of PA that is planned, structured, repetitive, and purposeful, and that is frequently employed for improving or maintaining optimal levels of physical fitness and function, is often used as complementary treatment for very prevalent, burdensome, and costly noncommunicable disease (NCD), such as heart disease [6], stroke [7], osteoarthritis [8], osteoporosis [9], and diabetes [10].

Despite this recognition, PA and exercise are rarely assessed and promoted in the primary care setting [11–14]. Furthermore, when primary care physicians (PCPs) discuss PA with patients, discussions are short (1.5 min on average) and rarely involve providers’ recommendations [15]. Indeed, lack of time is the most important barrier to PA counselling in primary care [16]. Furthermore, researchers have estimated that a physician would need to spend 108 h per year (i.e. >5% of the total average physician time per year) to provide the recommended PA counselling to patients [17]. Besides lack of time, lack of knowledge of PA and lack of counselling protocols, which are completely lacking in the context of multimorbidity (i.e. the presence of two or more chronic conditions), constitute obstacles to PA counselling in primary care. The high prevalence of NCDs and, most importantly, multimorbidity among patients in primary care [18–20] increases, therefore, the difficulty in providing adequate PA counselling in this clinical setting.

The purpose of this current opinion article was to discuss guidelines for the management of the most prevalent chronic diseases treated by PCPs in order to identify the best exercise regimen for each clinical population and to provide preliminary guidance for primary care providers on exercise counselling in the ‘real-world’ context of multimorbidity.

2 Multimorbidity in Primary Care

Studies relating to the prevalence of NCDs and multimorbidity in primary care are sparse [21]. These areas were recently investigated in a cross-sectional study in the US using the PPRNet database, a national primary care practice-based research network, with data from 148 primary care practices, for a total of 667,379 patients aged ≥18 years [18]. The PPRNet found that one-third of patients had either hypertension or hyperlipidaemia, and almost half had multimorbidity [18]. A small number of observational studies in European countries have also investigated the prevalence of NCDs and multimorbidity in primary care adult patients [19–23]. A list of some of the most prevalent chronic conditions for adults aged ≥18 years currently treated in primary care in the US and Europe is presented in Table 1. Beyond individual prevalence, co-occurrence among the conditions presented in Table 1 is very common [20, 23–25]. Hypertension often co-occurs with hyperlipidaemia and/or heart disease and/or diabetes and/or obesity, while patients with either diabetes or heart disease often have hypertension and/or hyperlipidaemia and/or obesity. Asthma, as well as chronic obstructive pulmonary disease (COPD) [26], often co-occurs with hypertension and/or diabetes and/or heart disease [24, 27]. Additionally, subjects suffering from back pain frequently have osteoarthritis or osteoporosis. Several of these diseases are often associated with depression.

Table 1 Some of the most prevalent chronic conditions among adults aged ≥18 years treated in the primary care setting in the US and in European countries [18–22]
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3 Methodological Considerations

Although this article is not a literature review, an electronic search was performed in order to gather information on the main diseases currently treated by PCPs. The recent literature relating to chronic conditions among adult patients in primary care was first searched in PubMed in order to identify the most prevalent diseases treated in this setting. We restricted our search (see electronic supplementary material Table S1) to articles published from 2011 onwards (last 5 years) in an attempt to obtain data likely to mirror the reality of conditions currently treated by PCPs. Articles using any study design (except controlled trials, as interventional studies, such as exercise training, may impact the management of NCDs and therefore the patient’s needs and use of primary care resources) were selected if they reported data relating to the prevalence of diseases treated in primary care. References of the retrieved articles [18–22], which included a systematic review [21], were cross-matched to find other potentially relevant studies. From the retrieved articles, some of the most prevalent conditions treated in primary care were identified, as shown in Table 1.

To examine whether PA and exercise are part of best practice for the management of specific diseases according to current guidelines, we examined the recommendations provided by recognised learned/scientific societies for the management of each disease and identified any recommendation involving PA and exercise. We also examined whether the American College of Sports Medicine (ACSM) has published specific recommendations for the diseases, the ultimate goal being to identify the best exercise prescription for each clinical population. Although no objective criteria were used for the selection of societies, all are well-established and internationally recognised learned/scientific societies responsible for the elaboration of disease management guidelines for the specific chronic conditions examined.

4 Current Physical Activity and Exercise Recommendations for Selected Chronic Conditions

Table 2 shows, for each disease, the learned/scientific societies investigated, whether their recommendations involved PA and exercise, and the exact PA and exercise recommendations provided. For the majority of the 11 conditions examined, the learned/scientific societies clearly identified exercise as an important factor in disease management. For cardiovascular and metabolic conditions, i.e. hypertension, hyperlipidaemia, diabetes, obesity, and heart disease, exercise is a well-established aspect of disease treatment, leading learned/scientific societies to propose precise exercise guidelines for patients with those conditions. Although these societies identified PA and exercise as an aspect of the treatment of musculoskeletal and bone conditions, i.e. osteoporosis, back pain and osteoarthritis, precise exercise prescriptions for those patients were rare. If reported, the prescriptions were the same as the current international PA guidelines for public health [63], i.e. at least 150 min per week of moderate-intensity aerobic PA, or 75 min per week of vigorous-intensity aerobic PA, or an equivalent combination of moderate- and vigorous-intensity aerobic activity and muscle-strengthening activities of moderate or high intensity on 2 or more days a week (national guidelines in most countries, including the US and the UK, are similar to these international guidelines). Information relating to the role of PA and exercise for the management of asthma remains inconclusive. Gastroesophageal reflux disease (GERD) was the sole condition for which PA and exercise were not considered important aspects of disease management. However, since one of the recommendations for the management of GERD is weight loss for overweight subjects or those who have recently gained weight, it is plausible to suggest that PA and exercise may play an indirect role in a subpopulation of patients with this condition.

Table 2 Recommendations relating to physical activity in guidelines for the management of the most prevalent chronic conditions treated in primary care practice
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Examination of the reports from the learned/scientific societies (Table 2) revealed that the exercise prescriptions for different diseases were very similar. For example, the exercise prescription for hypertensive patients [25, 26], patients with hyperlipidaemia [25, 27], those with type 2 diabetes [32–36], patients with heart disease (coronary artery disease) [54], and patients with depression [29] suggests that patients should undertake 120–180 min per week of moderate-to-vigorous activity. For patients with obesity [37–40] or heart failure [53, 54], a minimum of 150 min per week of PA applies, but societies suggest up to 300 min per week. In patients with obesity, for example, this higher rate of PA is more effective for avoiding weight regain [39, 40]. Osteoporosis guidelines appear to provide similar recommendations (30 min daily) [49]. Resistance training, i.e. exercises performed to improve muscle strength, is part of the exercise prescription for several conditions, such as diabetes, osteoarthritis, osteoporosis and heart disease; exercises of moderate- to vigorous-intensity two to three times per week is prescribed for all of these conditions.

5 A Standardised Exercise Prescription for Patients with Asymptomatic Conditions

Since the exercise recommendations vary only minimally across the most prevalent chronic conditions, multimorbid patients with asymptomatic diseases may, in theory, benefit from a single, standardised exercise prescription, with only minimal adaptations to the specificities of some diseases (e.g. patients with osteoporosis should be encouraged to do weight-bearing, rather than water-based, activities). On the basis of the guidelines examined and displayed in Table 2, an example of a standardised, cross-disease exercise prescription is proposed in Table 3; however, it is important to note that this exercise prescription would only apply to asymptomatic patients who the PCP, on the basis of his/her clinical judgement, considers could start moderate-intensity exercise without the need for further specific examination. Multimorbid patients with signs and symptoms of their disease may require further medical examinations; these patients may also need to exercise under the surveillance of a clinical exercise physiologist or equivalent health professional.

Table 3 Standardised minimum exercise guideline for multimorbid patients with asymptomatic chronic conditions in the primary care setting
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Since, for most of the examined diseases, the PA and exercise prescription (Table 2) indicate patients should engage in 120–180 min per week of moderate-to-vigorous activity, this lower range was defined as the minimum PA that multimorbid patients should target. The example of a standardised guideline shown in Table 3 may represent a conservative approach for some conditions (e.g. obesity); however, it has the advantage of being safe and potentially effective for all patients provided their disease is asymptomatic. Moreover, this minimum exercise prescription can potentially be provided by the PCP in a brief advice format during a typical time-constrained consultation, especially when accompanied by supporting written material (e.g. electronic supplementary material Box S1).

The exercise prescription provided in Table 3 is similar to current public health guidelines on PA [63] but with three main differences:

  1. 1.

    It does not involve all PA domains. The total amount of exercise includes only leisure-time and commuting PA, which have been shown to result in superior health benefits [64]; occupational and household PA is not integrated into the suggested guideline.

  2. 2.

    The minimum PA rate of 120 min per week is less than the PA amount recommended in current public health guidelines (150 min per week), which suggests that the proposed standard prescription will probably be easier to adhere to over the long-term.

  3. 3.

    The proposed standardised guideline includes a prescription for reducing sitting time.

In regard to the last point, while no learned/scientific societies have integrated specific guidelines for reducing sitting time, important findings from recent well-conducted meta-analyses have found that increased sitting time is associated with a higher risk of type 2 diabetes, cardiovascular disease, and all-cause mortality [65, 66]. Mortality risk appears to be greater after 7 h per day of sitting time, and increases by 34% after 10 h per day of sitting [66]. The associations between sitting time and adverse health outcomes occur independently of PA levels.

6 Guidance for Primary Care Providers

Providing a comprehensive consultation guided by the ‘6As’ (assess, advise, agree, assist, arrange and assess again), as well as other practical steps [1] for prescribing an individualised exercise plan, should represent the ideal approach to increase PA levels among patients in primary care; however, most primary care doctors do not have the time, knowledge or intent to implement those steps. Nevertheless, their advice and capacity to stimulate participation in PA and exercise remain crucial for patients.

When assessing any patient with any of the chronic conditions listed in Table 1 (with the exception of GERD), or presenting with other diseases potentially treatable through exercise (e.g. COPD), primary care providers should systematically ask two questions [67]. (1) In a typical week, how many days do you engage in moderate or greater PA (such as a brisk walk) during your leisure time or to move from one location to another? (2) On each of those days, how many minutes do you spend doing such activities?

After multiplying the number of weekly days by the minutes spent in PA each day, healthcare providers can obtain the total weekly amount of leisure-time and commuting PA usually performed by the patient. If the total amount of PA is less than 120 min per week, the patient has no contraindication to exercise (see electronic supplementary material Box S2), and the PCP judges the patient as being clinically able to undertake moderate-intensity activity, he/she should provide the patient with a standardised minimum exercise prescription, as shown in Table 3, together with written supporting resources (electronic supplementary material Box S1). It is important to note that the exercise prescription should be a formal medical prescription, just like a drug prescription (with the physician’s stamp and signature).

7 Conclusions

Exercise is an important component of the treatment of several prevalent and burdensome chronic diseases, thus making it part of best practice for such conditions. Providing multimorbid patients with an exercise prescription is therefore the duty of any healthcare provider, particularly in the primary care setting. Individualising counselling [68], after examining the patient’s readiness for behavioural change and establishing suitable specific goals, is an effective approach to promote PA in adults in primary care practice, and this individualised counselling approach should be pursued whenever possible. However, counselling patients about PA and exercise in this setting remains rare [16] because it is time-consuming, requires enhanced knowledge of exercise counselling, and no exercise guidelines have been developed for multimorbid patients.

Therefore, the approach to elaborating a standardised, minimum exercise guideline for patients with multiple chronic conditions proposed herein is an alternative to the traditional individualised exercise prescription. The construction of this standardised prescription is based on the thought that ‘doing something for my patients is better than doing nothing’. In other words, providing a nonindividualised exercise prescription is better than providing no exercise prescription. When providing any exercise guidelines, PCPs and other healthcare providers must keep in mind that any amount of PA and exercise is better than none. The dose–response association between PA and health benefits is well-established [69–72], with the greatest benefit found when subjects move from a sedentary behavior to being slightly active [69, 72]. They should also provide positive feedback for patients who start doing some exercise, even though these patients do not achieve the levels of exercise recommended in the guidelines. PCPs should advise patients about local resources for PA and exercise, such as health and fitness centres or sports clubs (e.g. hiking clubs), in the neighbourhood. Encouraging patients to find other peers to exercise with may be important for long-term adherence to exercise [73].

Although the elaboration of a standardised exercise guideline for multimorbid patients suffering from the most prevalent NCDs managed by PCPs is very attractive, future research is needed to validate this approach and to define the best structure (e.g. guidelines in the form of bullet points or script) and content of standardised minimum exercise guidelines in terms of (cost-) effectiveness for well-defined subgroups of multimorbid patients.