Introduction

Tendinopathy is an overuse injury of tendons [1]. It occurs frequently in athletes, as 30 to 50 percent of injuries in sports are tendon injuries [1,2]. Athletes participating in a variety of sports are at risk of developing tendinopathy [2]. However, not only athletes suffer from tendinopathy. In a general population, researchers found an incidence rate of 10.52 per 1000 persons per year and a prevalence rate of 11.83 per 1000 persons per year [3]. Physical therapists and other therapists often treat patients with tendinopathy in their daily practice [4]. Tendinopathy has a negative impact on quality of life, work ability and social and sports participation, and it is known for its poor prognosis [3]. Pain, loss in function and structural changes may occur in both upper and lower extremities, which tends to result in incapacity to repeatedly load the tendon [4]. In tendinopathy, the tendonbone attachment is more frequently affected than the mid-tendon [4].While structural changes in tendons are not considered key factors in tendinopathy [4,5], pain and loss in function are important to address [4,5]. Recovery of tendinopathy is on average slow and tendinopathy is difficult to treat [3,6]. Among the multiple treatment options that are described in the scientific literature, load management and slowly progressing exercise programs are generally considered the best methods to treat pain and loss in function [1,6]. A combination of eccentric exercises, isometric exercises, heavy slow resistance training, plyometric exercises and flywheel training can be used [7-9]. Empirical research has found that observable structural changes in tendons are not an explanation for how tendons respond to exercises [4,5]. In addition to exercises and loading modifications, intrinsic factors, which have be found to be risk factors for tendinopathy, such as genes, age, body composition and co-morbidities can play a role in the treatment of tendinopathy [4,10]. Lifestyle factors, which are health-related behaviours or the potential results of such behaviours [11], have also been found to be risk factors for tendinopathy [4,6,10,11]. The purpose of this clinical commentary is to inform physical therapists and other therapists about the role of lifestyle factors both as risk factors and as treatment options in tendinopathy. To this end, lifestyle factors associated with tendinopathy as well as treatment options to modify lifestyle and thereby impact tendon recovery are discussed.

Lifestyle factors as risk factors for tendinopathy

Lifestyle comprises health-related behaviours and their consequences [11]. One can think of behaviours like general activity levels, sleep, nutrition, smoking, alcohol use, and stressrelated behaviour. Unhealthy lifestyle behaviours are associated with a variety of negative outcomes, such as chronic pain, lowgrade inflammation, elevated adiposity, higher waist-to-rib ratio, greater body mass index, overweight, obesity, high cholesterol, metabolic syndrome, diabetes type II, rheumatoid arthritis and inflammatory-related diseases [2,3,6,12-18]. There are guidelines to inform people about a healthy lifestyle [15]. International guidelines agree about the importance of daily movement and recommend 150 minutes of moderate intense movement per week [15]. Moreover, a diet rich in vegetables, fruit, fish and whole-grains fits best in a healthy lifestyle [15]. Recommendations about sleep and psychosocial factors are relatively limited [15]. Nevertheless, experts describe good sleep quality as feeling rested in the morning without having been awake for more than 30 minutes during the night, and good sleep quantity is defined as 7 to 10 hours a night [11]. Stress as a psychological factor is difficult to assess objectively, yet high and chronic stress levels are not recommended [11]. Health guidelines advice against any smoking and alcohol use is only advised in moderation (i.e., not more than 5 glasses a week and not more than 2 glasses a day) [15]. Failure to meet these healthy lifestyle criteria is likely to result in higher risk of developing tendinopathy [2,3,6].