Case report: A creatine kinase-borg scale values-based approach to tailor physical training in a central core myopathy patient

Abstract

Background: Patients with central core myopathy (CCM) can be at risk of exercise-induced rhabdomyolysis and myalgia. Despite its possible positive effects, physical training has been long avoided in these patients as no population-specific exercise adaption strategies have been developed. Here we present the case of a 17-year-old male CCM patient who underwent a 3-month training program tailored to a preliminary test aimed at assessing his physical exertion tolerance measured via changes in serum creatine kinase (CK).

Methods: The preliminary tolerance test consisted of three 25-minute sessions (one session per week) of physical exercise (aerobic, resistance and mixed) at an intensity quantified as level 6 of the Borg Category Ratio (CR) 0-10 scale. A blood sample to assess CK was conducted 36 h following eachsession. The intervention consisted of a training program (three sessions per week) including both resistance and aerobic exercises concomitant with a personalized nutritional plan. Before and after intervention, a battery of metabolic (indirect calorimetry, bioimpedance) and cardiopulmonary (CPET) tests were performed.

Results: After training, improvements of the anaerobic threshold (+6.9%), normalized VO₂ max (+15%) and body composition (muscle mass, +1.1 kg; fat mass, -1.1 kg were observed without pain, rhabdomyolysis, and blood CK augmentation compared to pretraining values.

Conclusion: Our results highlight that a mixed aerobic/resistance training, properly tailored and supported by a specific nutritional plan, may safely improve the physical fitness and body composition in a CCM patient. Dosing exercise-induced CK serum change following Borg CR-10 intensity assessment, may be useful to correctly tailor physical exercise in these patients.

Keywords: aerobic training; creatine kinase; exercise tailoring; neuromuscular disorder; resistance training.

FIGURE 1

Timeline of case’s salient events.

FIGURE 2

Trend of CK values over time. The white columns represent the values obtained in the last three routine checks carried out before contacting our centre. The December 2022 and January 2023 values have been entered to show data relating to the patient’s normal CK values. The February 2023 value, as specified, was obtained following the at home unsupervised physical activity. The black columns refer to the values obtained 36 h after the training sessions of the preliminary test. The grey column refers to the value obtained 36 h after the last session of the training program.