Article of the month of May by Dr. David Burke
Circuit training (CT) is a combined exercise strategy incorporating both multi-joint resistance training and calisthenics to maintain an elevated heart rate during the training session. This study assessed the effect of periodized circuit training (PCT) on muscle strength and intramuscular fat in patients with osteoarthritis (OA) of the knee.
The subjects were 40-65 years of age, diagnosed with knee OA. At baseline patients were evaluated for strength, and by CT for muscle quality and fat content. Subjects randomized to receive PCT, strength training (ST) three sessions per week for 14 weeks, or to an educational protocol (EP). For the PCT group, exercises were arranged in a circuit model: upper body, lower body, and trunk and global exercises and stratified according to the stress intensity levels. The ST protocol included exercises at 50% of the one rep maximum (1 Rep Max) for the quadriceps and hamstrings and 25% of the 1 Rep Max for the hip abductors and abductors. The education protocol occurred twice per month in 60-minute sessions for 14 weeks.
Compared with baseline, changes in knee extension strength were +21% (p=0.024) in the PCT, +28% (p<0.001) and -4% in the education group. The VAS pain scores improved by 74.89 (p < 0.001) in the PCT group, 72.4% in the ST group (p < 0.001), and 3.27 % in the EP group. Reductions in intramuscular fat were 16% in the PCT group, and 6% in the EP group (p=0.032).
This study of patients with knee osteoarthritis addresses the association between intramuscular fat, pain, strength, comparing the efficacy of two methods of training in addressing these. While both methods were effective in increasing strength, and reducing pain, periodized training was found to be superior to conventional strength staining for reducing intramuscular fat.
de Almeida, A et al. A Periodized Training Attenuates Thigh Intramuscular Fat and Improves Muscle Quality in Patients with Knee Osteoarthritis: Results from a Randomized Controlled Trial. Clin Rheum. 2020; 39:1265–1275