MedXFit: CrossFit® as a workplace health intervention

Background The MedXFit-study analyzed whether CrossFit® (CF) as a workplace health intervention (WHI) motivates inactive, sedentary employees to long-term training participation in order to improve health and fitness. Method The study followed a prospective, controlled intervention design and was registered on ClinicalTrials.gov with the trial number NCT05109286. Fifty-five and 34 participants in the intervention (IG) and control group (CG) were measured at baseline (t0), 6 months (t1), and 12 months (t2). Civilian and military members of the University of the Bundeswehr Munich (UniBw M) with a predominantly sedentary occupation who performed less than two strength and/or flexibility training sessions per week were included. While the IG attended CF training twice a week for 60 minutes, the CG was free to use the extensive fitness classes and facilities of the UniBw M (including yoga, spinning, aqua fitness) during working hours. Whether CF contributed to long-term behavioral change was determined by training adherence and evaluated based on the COM-B framework. This framework explains the occurrence of a target behavior via interactions between capability, opportunity, and motivation. Additionally, mobility, maximum strength, and well-being (WHO-5) were measured and analyzed for group differences using a mixed ANOVA. Back issues were assessed exploratively and analyzed by Mann-Whitney-U-test. Results Twenty-nine participants of the IG and 28 of the CG completed the study. Dropouts were primarily extrinsically motivated (extrinsic: IG = 16, CG = 5; intrinsic: IG = 10, CG =1), resulting in a non-adherence of 22%. After 12 months, participants of the IG completed 79.3 (± 19.3) CF training sessions on average. All participants of the IG stated that they would continue training after the study. Although participants benefited from great opportunity, behavioral maintenance was mainly driven by positive interactions between behavior, motivation, and capability. In terms of capability we found significant improvements in mobility (ⴄ² = .61), maximum strength (ⴄ² = .36 to ⴄ² = .62), back problems (pain intensity: r = .4; pain frequency: r = .35), and subjectively perceived movement competence. Conclusion CF proved to be an effective, long-term motivating training concept for inactive, sedentary employees and should be given greater consideration in the context of WHI.