Physical Exercise as Treatment for PTSD: A Systematic Review and Meta-Analysis.

INTRODUCTION: Post-traumatic stress disorder (PTSD) is a cluster of physical and psychiatric symptoms following military or civilian trauma. The effect of exercise on PTSD symptoms has previously been investigated in several studies. However, it has not been fully determined what type of exercise most impacts PTSD symptoms. The aim of the present study was to systematically review the effects of different types of exercise on PTSD symptom severity and symptoms of coexisting conditions in adults. MATERIALS AND METHODS: Electronic searches were conducted in the databases PubMed, APA PsycInfo, and SportDiscus, from database inception up until February 1, 2021. Inclusion criteria were randomized controlled trials published in English, participants having a PTSD diagnosis or clinically relevant symptoms, and participants randomly allocated to either a non-exercising control group or an exercise group. Data concerning the number of participants, age, exercise type and duration, PTSD symptom severity (primary outcome), and symptoms of coexisting conditions (secondary outcomes) were extracted. The subgroup analysis included high or low training dose, military trauma versus non-military trauma, the type of intervention (yoga versus other exercise), active or passive control condition, group training versus individual exercise, and study quality. The study quality and risk of bias were assessed using grading of recommendation assessment, development and evaluation (GRADE) guidelines. A meta-analysis was performed with a mixed-effects model and restricted maximum likelihood as model estimator, and effect size was calculated as the standardized difference in mean and 95% CI. RESULTS: Eleven studies were included in the present review. Results showed a main random effect of exercise intervention (0.46; 95% CI: 0.18 to 0.74) and a borderline significant interaction between more voluminous (>20 hours in total) and less voluminous (≤20 hours in total) exercise interventions (P = .07). No significant findings from the subgroup analysis were reported. The secondary outcome analysis showed a small but significant effect of exercise on depressive symptoms (0.20, 95% CI: 0.01 to 0.38), and a larger effect on sleep (0.51, 95% CI: 0.29 to 0.73). For substance use (alcohol and drugs combined) and quality of life, we found significant effects of 0.52 (95% CI: 0.06 to 0.98) and 0.51 (95% CI: 0.34 to 0.69), respectively. No significant effect was found for anxiety (0.18, 95% CI: -0.15 to 0.51), and no sign of publication bias was found. CONCLUSIONS: Exercise can be an effective addition to PTSD treatment, and greater amounts of exercise may provide more benefits. However, as there were no differences found between exercise type, possibly due to the inclusion of a low number of studies using different methodologies, further research should aim to investigate the optimal type, dose, and duration of activity that are most beneficial to persons with PTSD.

The ability of a submaximal cycle ergometer test to detect longitudinal changes in VO2max.

BACKGROUND: The purpose of the present study was to examine the ability of a submaximal cycling test to detect longitudinal changes in maximal oxygen uptake (VO2max) and examine the conformity between changes in measured and estimated VO2max over a time span of 5-8 years. METHODS: A total of 35 participants (21 men and 14 women), aged 29 to 63 years, performed the Ekblom-Bak (EB) submaximal cycle test for estimation of VO2max and a maximal treadmill running test for direct measurement of VO2max. The baseline tests were conducted between 2009 and 2012, and the follow-up tests were completed 5 to 8 years later. Pearson's coefficient of correlation (r) and paired sample t-test were used to analyse the association between change in measured and estimated VO2max. Random and systematic errors between the measured and estimated VO2max were evaluated using Bland-Altman plots. Repeated measures ANOVA were used to test differences between changes over time. RESULTS: There was no significant change in mean measured VO2max between baseline and follow-up (p = 0.91), however large individual variations were noted (- 0.78 to 0.61 L/min). The correlation between individual change in measured and estimated VO2max was r = 0.75 (p < 0.05), and the unstandardised B-coefficient from linear regression modelling was 0.88 (95% CI 0.61 to 1.15), i.e., for each litre of change in estimated VO2max, the measured value had changed 0.88 L. The correlation between baseline and follow-up errors (the difference between estimated-measured VO2max at each occasion) was r = 0.84 (p < 0.05). With regard to the testing procedure, repeated measures ANOVA revealed that there was no significant difference between the group who exercised at the same work rates at baseline and follow-up (n = 25), and those who required a change in work rate (n = 10). CONCLUSIONS: The EB test detected a change in VO2max with reasonably good precision over a time span of 5-8 years. Further studies are needed to evaluate if the test can be used in clinical populations and in subjects with different medications.

Sex and maturity status affected the validity of a submaximal cycle test in adolescents.

AIM: This study assessed the validity and reliability of the Ekblom-Bak (EB) submaximal cycle test in adolescents and identified any sex- or maturity-related factors for prediction errors. METHODS: We recruited 50 healthy subjects through a public announcement in Stockholm, Sweden, in 2016. The 27 boys and 23 girls were aged 10-15 years and in Tanner stages I-IV. They performed an EB test and incremental treadmill running test for direct measurement of maximal oxygen uptake (VO2 max). RESULTS: The estimation error of VO2 max was 0.09 L/min. The correlation (r) was 0.86, and the standard error of the estimate (SEE) was 0.29 L/min. The largest overestimation was seen in prepubertal boys (0.49 L/min). The best precision of the EB test was achieved when boys in Tanner stages I and II were re-calculated using the prediction equation developed for adult women. This yielded a mean difference of -0.05 L/min, r = 0.92 and SEE 0.23 L/min, in the entire sample. The prediction error was lowered in boys, but not girls, with increasing pubertal maturity. CONCLUSION: The EB test was reasonably valid in adolescents, seemed to be related to sex and maturity status, and our findings support its use.

Regular moist snuff dipping does not affect endurance exercise performance.

Physiological and medical effects of snuff have previously been obtained either in cross-sectional studies or after snuff administration to non-tobacco users. The effects of snuff cessation after several years of daily use are unknown. 24 participants with >2 years of daily snuff-use were tested before and after >6 weeks snuff cessation (SCG). A control group (CO) of 11 snuff users kept their normal habits. Resting heart rate (HR) and blood pressure (BP) were significantly lower in SCG after snuff cessation, and body mass was increased by 1.4 ± 1.7 kg. Total cholesterol increased from 4.12 ± 0.54 (95% CI 3.89-4.35) to 4.46 ± 0.70 (95% CI 4.16-4.75) mM L-1 in SCG, due to increased LDL, and this change was significantly different from CO. Resting values of HDL, C-reactive protein, and free fatty acids (FFA) remained unchanged in both groups. In SCG group, both HR and BP were reduced during a four-stage incremental cycling test (from 50 to 80% of VO2max) and a prolonged cycling test (60 min at 50% of VO2max). Oxygen uptake (VO2), respiratory exchange ratio, blood lactate (bLa) and blood glucose (bGlu) concentration, and rate of perceived exertion (RPE) were unchanged. In CO group, all measurements were unchanged. During the prolonged cycling test, FFA was reduced, but with no significant difference between groups. During the maximal treadmill running test peak values of VO2, pulmonary ventilation (VE), time to exhaustion and bLa were unchanged in both groups. In conclusion, endurance exercise performance (VO2max and maximal endurance time) does not seem to be affected by prolonged snuff use, while effects on cardiovascular risk factors are contradictory. HR and BP during rest and submaximal exercise are reduced after cessation of regular use of snuff. Evidently, the long-time adrenergic stress on circulation is reversible.

Validity of the revised Ekblom Bak cycle ergometer test in adults.

PURPOSE: To further develop the Ekblom Bak-test prediction equation for estimation of VO2max from submaximal cycle ergometry. METHODS: The model group (117 men and 100 women, aged 48.3 ± 15.7 and 46.1 ± 16.8 years, VO2max 46.6 ± 11.1 and 40.4 ± 9.6 mL kg(-1) min(-1), respectively) and the cross-validation group (60 men and 55 women, aged 40.6 ± 17.1 and 41.6 ± 16.7 years, VO2max 49.0 ± 12.1 and 43.2 ± 8.9 mL min(-1) kg(-1), respectively) performed 4 min of cycling on a standard work rate (30 W) directly followed by 4 min on a higher work rate. Heart rate (HR) at each work rate was recorded. Thereafter, participants completed a graded maximal treadmill test for direct measurement of oxygen uptake. The new prediction equation was cross-validated and accuracy compared with the original Ekblom Bak equation as well as by the Åstrand test method. RESULTS: The final sex-specific regression models included age, change in HR per-unit change in power (ΔHR/ΔPO), the difference in work rates (ΔPO), and HR at standard work rate as independent variables. The adjusted R (2) for the final models were 0.86 in men and 0.83 in women. The coefficient of variation (CV) was 8.7 % and SEE 0.28 L min(-1). The corresponding CV and SEE values for the EB-test2012 and the Åstrand tests were 10.9 and 18.1 % and 0.35 and 0.48 L min(-1), respectively. CONCLUSION: The new EB-test prediction equation provides an easy administered and valid estimation of VO2max for a wide variety of ages (20-86 years) and fitness levels (19-76 mL kg(-1) min(-1)).