Differential cardiac effects of aerobic interval training versus moderate continuous training in a patient with schizophrenia: a case report

The Influence of Continuous Exercising on Chronotropic Incompetence in Multi-Episode Schizophrenia

People with schizophrenia die on average 15-20 years earlier than age and gender matched controls in the general population. An essential part of this excess mortality in people with schizophrenia is caused by physical illnesses. Among the physical illnesses, cardiovascular disease (CVD) has been identified as the most common natural cause of death in up to 40-45% of the cases. Chronotropic incompetence (CI) is defined as the inability of the heart to increase its beating frequency in proportion to increased physical activity or higher metabolic demand. It is an established independent cardiovascular risk factor for major cardiac events and overall mortality and might explain adaptation intolerance of the cardiovascular system to even minor exercise courses. CI needs objective exercise testing for definitive diagnosis and therefore represents a biological marker indicating the integrity of the cardiovascular system. It was recently described in patients with schizophrenia and might help explain the reduced physical fitness in these patients and the inability of a subgroup of patients to benefit from exercise interventions. In this study, we tried to replicate the occurrence of CI in an independent sample of patients with schizophrenia and evaluated whether CI can be influenced by a continuous endurance training of 12 weeks. Therefore, we re-analyzed the fitness testing data of 43 patients with schizophrenia and 22 aged and gender matched healthy controls. Parameters of aerobic fitness and chronotropic response to exercise were calculated. Patients with schizophrenia were less physically fit than the healthy controls and displayed a significantly higher heart rate at rest. 10 of 43 patients with schizophrenia and no healthy control subject were classified as chronotropically incompetent. Chronotropic response to exercise did not change significantly after 12 weeks of continuous aerobic exercise training. No differences were observed for baseline heart rate and peak heart rate in both subgroups of schizophrenia patients. Aerobic fitness did not improve significantly in the patients with schizophrenia classified as chronotropically incompetent. Our results confirm the occurrence of CI in patients with multi-episode schizophrenia. This should be taken into account when planning an exercise or lifestyle intervention studies in this population. Schizophrenia patients with CI do not seem to benefit as well as schizophrenia patients without CI from aerobic exercise training interventions. Larger, prospective randomized controlled clinical trials with different training interventions are urgently needed to address the topic of schizophrenia patients not responding to exercise and the relationship to the illness itself.

Sprint Interval Training and Continuous Aerobic Exercise Training Have Similar Effects on Exercise Motivation and Affective Responses to Exercise in Patients With Major Depressive Disorders: A Randomized Controlled Trial

Background: Sprint interval training (SIT) has become increasingly popular and is seen as a promising exercise strategy to increase fitness in healthy people. Nevertheless, some scholars doubt the appropriateness of a SIT training protocol for largely physically inactive populations. SIT might be too arduous, and therefore contribute to feelings of incompetence, failure, and lower self-esteem, which may undermine participants' exercise motivation. Therefore, we examined whether participation in 12 SIT sessions would lead to different changes in self-determined motivation, affective responses to exercise, cardiorespiratory fitness, physical activity, and depressive symptom severity compared to aerobic exercise training (CAT) in a sample of patients with major depressive disorders (MDD). Methods: Two groups of 25 patients (39 women, 11 men) with unipolar depression were randomly assigned to the SIT or CAT condition (M = 36.4 years, SD = 11.3). Data were assessed at baseline and post-intervention (three weekly 35-min sessions of SIT/CAT over a 4-week period). Self-determined exercise motivation was assessed with a 12-item self-rating questionnaire, affective valence was assessed in each session, prior, during, and after the exercise training using the Feeling Scale (FS). Cardiovascular fitness was measured with a maximal bicycle ergometer test, self-perceived fitness with a 1-item rating scale, physical activity with the International Physical Activity Questionnaire (IPAQ-SF), and depressive symptom severity with the Beck Depression Inventory II (BDi-II). Results: The SIT and CAT groups did not differ with regard to their changes in self-determined motivation from baseline to post-intervention. Participants in the SIT and CAT group showed similar (positive) affective responses during and after the training sessions. Cardiorespiratory fitness, self-perceived fitness and depressive symptom severity similarly improved in the SIT and CAT group. Finally, significant increases were observed in self-reported physical activity from baseline to post-intervention. However, these increases were larger in the CAT compared to the SIT group. Conclusion: From a motivational point of view, SIT seems just as suited as CAT in the treatment of patients with MDD. This is a promising finding because according to self-determination theory, it seems advantageous for patients to choose between different exercise therapy regimes, and for their preferences with regard to exercise type and intensity to be considered.

Sprint interval training (SIT) substantially reduces depressive symptoms in major depressive disorder (MDD): A randomized controlled trial

Continuous aerobic exercise training (CAT) is considered a complementary treatment option in patients with major depressive disorder (MDD). Intermittent exercise training protocols, such as sprint interval training (SIT) have gained increasing popularity, but no studies on depressive symptoms following SIT in patients with MDD are available. Fifty-nine in-patients with MDD were randomly assigned to a SIT or CAT group. Medication was counterbalanced in both intervention arms. Both intervention groups received 3 weekly training sessions for 4-weeks (12 sessions in total). SIT comprised 25 bouts of 30 seconds at 80% of maximal power, whereas CAT consisted of 20 minutes of physical activity at 60% of maximal power. The training protocols were isocalorically designed. Maximal bicycle ergometer exercise testing yielded maximal and submaximal physical fitness parameters. The Beck-Depression-Inventory-II (BDI-II) was filled out by the patients before and after the intervention period. BDI-II scores substantially decreased in both groups with an effect size pointing towards a large effect (p < 0.001, η_p² = 0.70) while submaximal (0.07 < d < 0.89) and maximal (0.05 < d < 0.85) fitness variables improved in both groups. Short-term SIT leads to similar results as CAT in patients with MDD and can be regarded as a time-efficient and promising exercise-based treatment strategy.

Effects of Aerobic Exercise on Metabolic Syndrome, Cardiorespiratory Fitness, and Symptoms in Schizophrenia Include Decreased Mortality

Schizophrenia is a severe psychiatric disorder with a lifetime prevalence of about 1%. People with schizophrenia have a 4-fold higher prevalence of metabolic syndrome than the general population, mainly because of antipsychotic treatment but perhaps also because of decreased physical activity. Metabolic syndrome is a risk factor for cardiovascular diseases, and the risk of these diseases is 2- to 3-fold higher in schizophrenia patients than in the general population. The suicide risk is also higher in schizophrenia, partly as a result of depression, positive, and cognitive symptoms of the disease. The higher suicide rate and higher rate of cardiac mortality, a consequence of the increased prevalance of cardiovascular diseases, contribute to the reduced life expectancy, which is up to 20 years lower than in the general population. Regular physical activity, especially in combination with psychosocial and dietary interventions, can improve parameters of the metabolic syndrome and cardiorespiratory fitness. Furthermore, aerobic exercise has been shown to improve cognitive deficits; total symptom severity, including positive and negative symptoms; depression; quality of life; and global functioning. High-intensity interval endurance training is a feasible and effective way to improve cardiorespiratory fitness and metabolic parameters and has been established as such in somatic disorders. It may have more beneficial effects on the metabolic state than more moderate and continuous endurance training methods, but to date it has not been investigated in schizophrenia patients in controlled, randomized trials. This review discusses physical training methods to improve cardiorespiratory fitness and reduce metabolic syndrome risk factors and symptoms in schizophrenia patients. The results of studies and future high-quality clinical trials are expected to lead to the development of an evidence-based physical training program for patients that includes practical recommendations, such as the optimal length and type of aerobic exercise programs and the ideal combination of exercise, psychoeducation, and individual weight management sessions.

Endurance training in patients with schizophrenia and healthy controls: differences and similarities

The aims were to examine the feasibility of and adaptations to endurance training in persons diagnosed with schizophrenia and to address the question whether the principles and beneficial effects of endurance training established in the healthy population apply also to patients with schizophrenia. In this controlled interventional study, 22 patients with schizophrenia and 22 healthy controls performed a standardized aerobic endurance training on bicycle ergometers over 12 weeks. Another group of 21 patients with schizophrenia played table soccer. Endurance capacity was measured with incremental cycle ergometry before and after the intervention and 3 months later. A specific set of outcome parameters was defined. The training stimuli can be assumed to be similar in both endurance groups. Endurance capacity improved significantly in the endurance groups, but not in the table soccer group. Patients and healthy controls showed comparable adaptations to endurance training, as assessed by physical working capacity and maximal achieved power. Differences were found in changes of performance at a lactate concentration of 3 mmol/l. Endurance training was feasible and effective in both groups. The principles and types of training that are usually applied to healthy controls need to be verified in patients with schizophrenia. Nevertheless, patients benefited from endurance training in terms of improvement of endurance capacity and reduction in the baseline deficit in comparison with healthy controls. Therefore, endurance training should be implemented in future therapy programs. These programs need to pay special attention to the differences between patients with schizophrenia and healthy controls.

Running for your life: A review of physical activity and cardiovascular disease risk reduction in individuals with schizophrenia

Individuals with schizophrenia have a greater risk for cardiometabolic risk factors (e.g. central obesity, insulin resistance, hypertension and dyslipidaemia), cardiovascular diseases and mortality. This risky profile may be explained by the adverse effects of antipsychotic medications and an unhealthy lifestyle (e.g. smoking, poor nutrition and low physical activity). In the general population, physical activity has been shown to be the optimal strategy to improve both cardiometabolic parameters and cardiorespiratory fitness levels. Accordingly, an emerging literature of non-pharmacological interventions (e.g. cognitive behavioural therapy, diet and physical activity) has been studied in individuals with schizophrenia. Therefore, the purpose of this review was 1) to conduct a critical literature review of non-pharmacological interventions that included some kind of physical activity (including supervised and unsupervised exercise training) and target cardiometabolic risk factors in individuals with schizophrenia. 2) To describe the contribution of physical activity alone by reviewing trials of supervised exercise training programmes only. A literature review via systematic keyword search for publications in Medline, PubMed, Embase and PsycINFO was performed. Many non-pharmacological interventions are efficient in reducing cardiovascular disease risk factors when combined with physical activity. Supervised physical activity has been successful in decreasing cardiovascular disease risk, and aerobic interval training appears to provide more benefits by specifically targeting cardiorespiratory fitness levels. In conclusion, physical activity is an effective strategy for addressing cardiovascular disease risk in individuals with schizophrenia. Long-term studies are needed to evaluate the feasibility and impact of exercise training programmes in individuals with schizophrenia.

Cardiac Autonomic Dysfunction in Patients with Schizophrenia and Their Healthy Relatives - A Small Review

The majority of excess mortality among people with schizophrenia seems to be caused by cardiovascular complications, and in particular, coronary heart disease. In addition, the prevalence of heart failure and arrhythmias is increased in this population. Reduced efferent vagal activity, which has been consistently described in these patients and their healthy first-degree relatives, might be one important mechanism contributing to their increased cardiac mortality. A decrease in heart rate variability and complexity was often shown in unmedicated patients when compared to healthy controls. In addition, faster breathing rates, accompanied by shallow breathing, seem to influence autonomic cardiac functioning in acute unmedicated patients substantially. Moreover, low-physical fitness is a further and independent cardiac risk factor present in this patient population. Interestingly, new studies describe chronotropic incompetence during physical exercise as an important additional risk factor in patients with schizophrenia. Some studies report a correlation of the autonomic imbalance with the degree of positive symptoms (i.e., delusions) and some with the duration of disease. The main body of psychiatric research is focused on mental aspects of the disease, thereby neglecting obvious physical health needs of these patients. Here, a joint effort is needed to design interventional strategies in everyday clinical settings to improve physical health and quality of life.

Effectiveness of high-intensity interval training on the mental and physical health of people with chronic schizophrenia

BACKGROUND

Low-volume high-intensity interval training (HIIT) is emerging as a time-efficient exercise strategy for improving cardiorespiratory fitness and for controlling blood sugar levels and hypertension. In addition, patient acceptance of HIIT may improve adherence to exercise programs. This study evaluated the effectiveness of HIIT for improving the mental and physical health of people with chronic schizophrenia.

METHODS

Twenty patients attending a psychiatric day care unit volunteered for an 8-week program of HIIT. Blood pressure, resting heart rate, body weight, body mass index, waist and hip circumference, and waist-to-hip ratio were measured weekly. The Positive and Negative Syndrome Scale score was recorded at baseline and at the end of the study. Beck Depression Inventory (BDI) and Beck Anxiety Inventory (BAI) scores were recorded every 2 weeks.

RESULTS

Statistically significant changes occurred in the physical and mental parameters measured in the 18 patients who completed the study. Body weight, body mass index, resting heart rate, and pulse pressure decreased significantly. Mean arterial pressure and diastolic blood pressure increased significantly. Mental health scores improved, with the Negative Scale score decreasing from 31.17±5.95 to 27.78±3.57 (P<0.01) and the General Psychopathology Scale score from 14.28±2.16 to 13.00±1.72 (P<0.01). Positive Scale scores changed, but not significantly, from 12.28±2.27 to 12.33±2.00 (P=0.729). Scores on the BDI (from 19.56±15.28 to 15.89±14.33, P<0.001) and BAI (from 13.67±13.83 to 10.06±11.18, P=0.003) both improved significantly.

CONCLUSION

This study demonstrated that HIIT has positive effects on the physical and mental health of patients with chronic schizophrenia.