ObjectivesTo investigate cartilage tissue turnover in response to a supervised 12-week exercise-related joint loading training program followed by a 6-month period of unsupervised training in patients with knee osteoarthritis (OA). To study the difference in cartilage tissue turnover between high- and low-resistance training.MethodPatients with knee OA were randomized into either high-intensity or low-intensity resistance supervised training (two sessions per week) for 3 months and unsupervised training for 6 months. Blood samples were collected before and after the supervised training period and after the follow-up period. Biomarkers huARGS, C2M, and PRO-C2, quantifying cartilage tissue turnover, were measured by ELISA. Changes in biomarker levels over time within and between groups were analyzed using linear mixed models with baseline values as covariates.ResultshuARGS and C2M levels increased after training and at follow-up in both low- and high-intensity exercise groups. No changes were found in PRO-C2. The huARGS level in the high-intensity resistance training group increased significantly compared to the low-intensity resistance training group after resistance training (p = 0.029) and at follow-up (p = 0.003).ConclusionCartilage tissue turnover and cartilage degradation appear to increase in response to a 3-month exercise-related joint loading training program and at 6-month follow-up, with no evident difference in type II collagen formation. Aggrecan remodeling increased more with high-intensity resistance training than with low-intensity exercise.These exploratory biomarker results, indicating more cartilage degeneration in the high-intensity group, in combination with no clinical outcome differences of the VIDEX study, may argue against high-intensity training.
Background: Knowledge concerning the feasibility and effects of progressive resistance training (PRT) for persons with intellectual disabilities and visual impairment who are categorized in Gross Motor Function Classification System (GMFCS) Level 1 is limited. The aim of our study was to evaluate feasibility and effect of PRT on participants' Quadriceps strength and personal goals.Methods: Eight Participants followed a PRT program for 10 weeks. Feasibility wasdetermined by percentage of attendance and compliance. The effect of PRT was analyzed with a linear mixed model (p < 0.05) and by normalized bootstrap (95% CI).Results: Participants attended 87.8% of the sessions and trained according to thePRT program, indicating sufficient compliance. Quadriceps strength increased significantly by 69%, and participants' personal goals were achieved.Conclusion: PRT is a feasible and potentially effective method for increasingQuadriceps strength as well as achieving personal goals in persons with intellectual disabilities and visual impairment with GMFCS Level 1.
ObjectivesChronic systemic low grade inflammation is associated with the age-related loss of muscle mass. Resistance exercise has been suggested to reduce or lower chronic systemic low grade inflammation. However, systemic chronic low-grade inflammation may adversely affect the adaptive response to exercise training. We investigated the effect of resistance exercise training on systemic chronic low-grade inflammation in older adults. In addition, we studied the association between systemic chronic low-grade inflammation and the adaptive response to exercise training.Design/setting/participantsFrail and pre-frail older adults (61 subjects) performed 24 weeks of progressive resistance exercise training. Frailty was assessed using the Fried frailty criteria.MeasurementsLean body mass (DXA), strength (1RM), circulating levels of IL-1β, IL-6, IL-8 and TNF-α were measured prior to exercise training, after 12 weeks of training, and after 24 weeks of training.ResultsProlonged progressive resistance exercise training did not affect circulating levels of IL-6, IL-8 and TNF-α. However, exercise training led to a small but significant increase of 0.052 pg/mL in IL-1β. Higher circulating levels of TNF-α, IL-8 and IL-6 during the training period were negatively associated with strength gains for the leg press. A doubling of plasma TNF-α, IL-8 or IL-6 resulted in reduced strength gains for leg press with coefficients of −3.52, −3.42 and −1.54 respectively. High levels of circulating TNF-α were also associated with decreased strength gains for the leg extension (coefficient −1.50). Inflammatory cytokines did not appear to have an effect on gains in lean mass.ConclusionOur findings suggest that increased levels of plasma cytokines (TNF-α, IL-6 and IL-8) are associated with lower strength gains during resistance exercise training.
