Therapeutic effects of maximal strength training on walking efficiency in patients with schizophrenia - a pilot study

Abstract

Background Patients with schizophrenia frequently have disabling gait deficits. The net mechanical efficiency of walking (ϵ net ) is an accurate measure often used to evaluate walking performance. Patients with gait deficits have a reduced ϵ net with excessive energy expenditure during sub-maximal walking. Maximal strength training (MST) improves ϵ net in healthy individuals and is associated with reduced risk of mortality. The aim of this study was to investigate whether MST improves ϵ net in patients with schizophrenia.

Methods Patients (ICD-10 schizophrenia, schizotypal or delusional disorders (F20-F29)) were included in a non-randomized trial. Patients were assigned to one of two groups: 1) MST consisting of 4x4 repetitions at 85-90% one repetition maximum (1RM) performed in a leg press apparatus or 2) playing computer games (CG). Both groups carried out their activity three days per week for eight weeks. 1RM, ϵ net at 60 watt walking, peak oxygen uptake (VO2peak), the Positive and Negative Syndrome Scale (PANSS) and the 36-items short form (SF-36) were measured pre and post intervention.

Results The baseline ϵ net was 17.3 ± 1.2% and 19.4 ± 3.0% in the MST (n = 6) and CG groups (n = 7), respectively, which is categorized as mechanical inefficiency. The MST group improved 1RM by 79 kg (p = 0.006) and ϵ net by 3.4% (p = 0.046) more than the CG group. The MST group improved 1RM and ϵ net , by a mean of 83 kg (p = 0.028) and 3.4% (p = 0.028), respectively. VO2peak at baseline was 34.2 ± 10.2 and 38.3 ± 9.8 ml·kg-1·min-1 in the MST and CG groups, respectively, and did not change (p > 0.05). No change was observed in PANSS or SF-36 (p > 0.05).

Conclusions MST improves 1RM and ϵ net in patients with schizophrenia. MST could be used as a therapeutic intervention for patients with schizophrenia to normalize their reduced ϵ net .