Background: Patients with schizophrenia have a high risk of cardiovascular disease (CVD). High aerobic intensity training (HIT) improve peak oxygen uptake (VO2peak), net mechanical efficiency of walking and risk factors for CVD but has not been investigated in patients with schizophrenia. Aims: To investigate effects from HIT on VO2peak, net mechanical efficiency of walking and risk factors for CVD in patients with schizophrenia. Methods: 25 inpatients (F20-29, ICD-10) were allocated to either HIT or playing computer games (CG), 3 days per week for 8 weeks. HIT consisted of 4 × 4-min intervals with 3-min break periods, at 85-95% and 70% of peak heart rate, respectively. Results: 12 and seven patients completed HIT and CG, respectively. The baseline VO2peak in both groups combined (n = 19) was 36.8 ± 8.2 ml/kg/min and 3.12 ± 0.55 1/min. The HIT group improved VO2peak by 12% from 3.17 ± 0.59 to 3.56 ± 0.68 1/min (P < 0.001), more than the CG group (P = 0.014). Net mechanical efficiency of walking improved by 12% in the HIT group from 19.8 ± 3.0% to 22.2 ± 4.5% (P = 0.005), more than the CG group (P = 0.031). The psychiatric symptoms, expressed as the Positive and Negative Syndrome Scale (PANSS) and the Calgary Depression Scale for Schizophrenia (CDSS), did not improve in either group. Conclusions: VO2peak and net mechanical efficiency of walking improved significantly by 8 weeks of HIT. HIT should be included in rehabilitation in order to improve physical capacity and contribute risk reduction of CVD.

This study compared maximal strength training (MST) with equal training volume (kg × sets × repetitions) of conventional strength training (CON) primarily with regard to work economy, and second one repetition maximum (1RM) and rate of force development (RFD) of single leg knee extension. In an intra-individual design, one leg was randomized to knee-extension MST (4 or 5RM) and the other leg to CON (3 × 10RM) three times per week for 8 weeks. MST was performed with maximal concentric mobilization of force while CON was performed with moderate velocity. Eight untrained or moderately trained men (26 ± 1 years) completed the study. The improvement in gross work economy was -0.10 ± 0.08 L min(-1) larger after MST (P = 0.011, between groups). From pre- to post-test the MST and CON improved net work economy with 31 % (P < 0.001) and 18 % (P = 0.01), respectively. Compared with CON, the improvement in 1RM and dynamic RFD was 13.7 ± 8.4 kg (P = 0.002) and 587 ± 679 N s(-1) (P = 0.044) larger after MST, whereas isometric RFD was of borderline significance 3,028 ± 3,674 N s(-1) (P = 0.053). From pre- to post-test, MST improved 1RM and isometric RFD with 50 % (P < 0.001) and 155 % (P < 0.001), respectively whereas CON improved 1RM and isometric RFD with 35 % (P < 0.001) and 83 % (P = 0.028), respectively. Anthropometric measures of quadriceps femoris muscle mass and peak oxygen uptake did not change. In conclusion, 8 weeks of MST was more effective than CON for improving work economy, 1RM and RFD in untrained and moderately trained men. The advantageous effect of MST to improve work economy could be due to larger improvements in 1RM and RFD.

BackgroundPatients with schizophrenia frequently have disabling gait deficits. The net mechanical efficiency of walking (ϵnet) is an accurate measure often used to evaluate walking performance. Patients with gait deficits have a reduced ϵnet with excessive energy expenditure during sub-maximal walking. Maximal strength training (MST) improves ϵnet in healthy individuals and is associated with reduced risk of mortality. The aim of this study was to investigate whether MST improves ϵnet in patients with schizophrenia.MethodsPatients (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, ϵnet 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.ResultsThe baseline ϵnet 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 ϵnet by 3.4% (p = 0.046) more than the CG group. The MST group improved 1RM and ϵnet, 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).ConclusionsMST improves 1RM and ϵnet in patients with schizophrenia. MST could be used as a therapeutic intervention for patients with schizophrenia to normalize their reduced ϵnet.