To evaluate the effects of a periodized circuit training (CT) compared with a conventional strength training (ST) and an educational protocol (EP) on body composition, metabolic parameters, muscle strength, pain, and physical performance in patients with knee osteoarthritis (KOA).
This study followed a randomized controlled trial design. A sample of sixty-one patients with KOA, 40-65 years old and BMI < 30 kg/m2, were randomly divided into three 14-week protocols: CT, ST, or EP. The CT performed whole body exercises organized in circuit, 3 times a week. The ST performed conventional resistance exercises also 3 times a week, and the EP joined in educational meetings twice a month. Body composition (dual-energy X-ray absorptiometry (DXA)); metabolic parameters (abdominal obesity, triglyceride, HDL, blood pressure and fasting glucose), knee maximal isometric voluntary contraction (MIVC) extension and flexion, performance-based tests (40-m walk test, 30-s chair test, and stair climb test), self-reported pain, stiffness, and physical function (WOMAC) and pain catastrophism were evaluated at baseline and follow-up. Repeated measures ANOVA were used to compare differences between groups (CTxSTxEP) at the different times of assessment (baseline × follow-up). When group-time interaction was found, a one-way ANOVA, followed by a Bonferroni post hoc test, was used to compare groups in each time point; while a paired t test was used to verify the time effect in each group. Additionally, the training effect was analyzed in terms of the percent change (Δ%). Effect size was calculated for post intervention (week 14) between groups. For all analyses a significance level of 5% was adopted (p < 0.05).
The CT was the only protocol that presented significant lower body mass (p = 0.018; Δ% = - 1.4), fat mass (p = 0.017; Δ% = - 10.3), %fat mass (p < 0.001; Δ% = - 13.9), adipose indices (%fat trunk/%fat legs p = 0.031; Δ% = 7.8; fat mass/height2p = 0.011; Δ% = - 15.1; trunk/limb fat mass p = 0.012; Δ% = - 8.2; visceral adipose tissue (VAT) volume (cm3) p = 0.039; Δ% = - 11.6; VAT area (cm2) p = 0.044; Δ% = - 12.2), blood pressure levels (SBP p = 0.042; Δ% = - 3.4 and DBP p = 0.001; Δ% = - 4.9), higher lean mass and HDL (p < 0.001; Δ% = 5.9) compared to baseline. CT and ST presented lower WOMAC pain, stiffness and physical function (p < 0.001; Δ% = - 64.0 for CT and p < 0.001; Δ% = 0.001; Δ% = - 46.4 for ST in WOMAC total score, pain catastrophizing (p < 0.001; Δ% = - 66.7 for CT and p < 0.001; Δ% = - 61.5 for ST) a higher functional performance (30 s chair test: p < 0.001; Δ% = 45.7 for CT and p < 0.001; Δ% = 26.9 for ST; 40 m walk test: p < 0.001; Δ% = 26.7 for CT and p < 0.001; Δ% = 12.5 for ST; stair climb test: p = 0.002; Δ% = - 33.9 for CT and p < 0.001; Δ% = - 18.8 for ST) and knee extension MIVC (p < 0.001; Δ% = 21.92 for CT and p < 0.001; Δ% = 30.25 for ST).
A periodized CT model reduces visceral adipose tissue, SBP and DBP, and improves HDL, important cardiovascular and metabolic risk factors, in patients with KOA. Both trained groups (CT and ST) improve self-reported clinical symptoms, muscle strength, and physical performance in this sample.
Trial registration number:
ClinicalTrials.gov, NCT02761590 (registered on May 4, 2016).
• A 14-week periodized circuit training reduces visceral adipose tissue, systolic and diastolic blood pressure, and improves HDL blood levels in patients with knee osteoarthritis.• Both periodized circuit training and conventional strength training improve clinical symptoms, functional performance and muscle strength in this sample.