Strength training restores force-generating capacity in patients with schizophrenia

Area of Science:

• Exercise Physiology
• Clinical Psychology
• Rehabilitation Science

Background:

• Patients with schizophrenia spectrum disorders exhibit diminished skeletal muscle force-generating capacity (FGC) and functional performance.
• This impairment affects lower extremity strength, including one-repetition maximum (1RM) and rapid force development.

Purpose of the Study:

• To determine if 12 weeks of maximal strength training (MST) could restore FGC and functional performance in schizophrenia patients to healthy reference levels.
• To assess MST's impact on patient activation and quality of life.
• To explore correlations between clinical factors (symptom severity, medication, illness duration, patient activation) and improvements in FGC and function.

Main Methods:

• Forty-eight outpatients with schizophrenia spectrum disorders were randomized into a training group (TG) or control group (CG).
• The TG engaged in leg press MST twice weekly at approximately 90% of 1RM.
• Assessments included leg press 1RM, rapid force development, functional performance tests, Patient Activation Measure-13, and the SF-36 Health Survey.

Main Results:

• The TG demonstrated significant improvements in 1RM (28%) and rapid force development (20%), reaching levels similar to healthy references (P < .01).
• No significant changes in FGC were observed in the CG.
• Improvements in rapid force development were negatively associated with the defined daily dose of medication (r = -0.5, P = .05).
• Both groups showed improvements in the 30-second sit-to-stand test, which correlated with enhanced rapid force development (r = 0.6, P < .05).

Conclusions:

• Twelve weeks of MST effectively restored lower extremity FGC in patients with schizophrenia spectrum disorders to levels comparable to healthy individuals.
• MST also led to improvements in functional performance, specifically the 30-second sit-to-stand test.
• The findings highlight MST as a viable intervention for improving physical capacity in this patient population.