Master athletes are defined as athletes >40 years old who maintain a high level of physical fitness despite the physiological effects of aging, allowing them to compete in sporting competitions (Reaburn and Dascombe,). Participation of master athletes is steadily increasing, especially in endurance events such as marathons (Jokl et al.,), and triathlons (Bernard et al.,), with male master triathletes accounting for 48% of male finishers in Ironman triathlons during 2007-2010 (Stiefel et al.,). Master athletes strive to maintain performances they achieved at younger ages, even though athletic performance inevitably declines with aging (Lepers et al.,; Lepers and Stapley,; Louis et al.,).
Regular physical activity throughout life can mitigate the age-related decline in muscle mass, muscle function, and cardiorespiratory capacity (Mian et al.,; Louis et al.,; Bieuzen et al.,). However, chronic high-level exercise as practiced by endurance master athletes may have adverse health implications including osteoarthritis (OA). OA is defined as the breakdown of joint cartilage and subsequently underlying bone as a result of joint inflammation (Friery,). Intense training programs, increased biomechanical load (Radin et al.,), and repetitive high impact activities such as long-distance running as well as family history, are among the main factors responsible for OA (Friery,). Although the precise relationship between training load and the risk of OA is not well-defined, many observational studies have reported an increased risk of knee and hip OA in former elite athletes (Lefevre-Colau et al.,). Team sports such as basketball, football, and hockey, that require many direction changes, present the highest risk of developing knee and hip OA (Lefevre-Colau et al.,). In endurance sports, the risk is lower but athletes still have a 1.73 increased chance of being admitted into hospital with severe OA, generally affecting lower limb joints (Kujala et al.,) at an average age of 59.7 years (Kettunen et al.,). The burden of OA is mainly caused by chronic pain, impaired function, and reduced quality of life (Cai et al.,).
The standard course of treatment for severe OA of the hip is a total arthroplasty which replaces the entire joint (Meira and Zeni,) or resurfacing arthroplasty which replaces the surfaces of the hip joint affected by OA (Oxblom et al.,). Resurfacing arthroplasty has become the preferred treatment for athletes because it preserves more bone. Whatever the technique used, the surgery is often preceded and followed by a period of reduced activity and even immobilization of lower limbs due to pain sensations about the joint. In general, the treated lower extremity is immobilized after a hip arthroscopy for 6-8 weeks (Stalzer et al.,; Wahoff and Ryan,). Such situation inevitably leads to a decrease in muscle mass, a possible reduction in bone mass, an increase in fat tissue, accompanied with metabolic, and functional alterations such as a loss in muscle strength (Houston et al.,; Suetta et al.,). The time period of ceased training also elicits reversibility of training adaptions that take considerably longer to re-establish than the time period of detraining (Houston et al.,). Furthermore, with the additional effect of aging, this may potentially result in the requirement of a longer reconditioning time period than that of younger athletes (Hvid et al.,). During immobilization and reconditioning, dietary intake also plays an important role and can support physiological adaptation for a quicker rehabilitation. Specifically, adapting energy intake to the changes in energy expenditure while maintaining a high protein intake can limit the decline in muscle mass (Louis et al.,). Little is known on the time-course of reconditioning and return to competition of young endurance athletes following surgery, and even less is known about deconditioning and reconditioning of master athletes.
With this in mind, we present the retraining and nutritional strategy that allowed an endurance master triathlete to return to competition 32 weeks following a hip arthroplasty. Training load, energy intake, body composition, and aerobic capacity were recorded at regular intervals during the period. Specifically we were interested in the changes in lean mass and bone mineral content that endured the combined effects of reduced physical activity and aging.