Validation of the maximal cardiopulmonary exercise test in adolescents with major depressive disorder and comparison of cardiorespiratory fitness with sex- and age-related control values.

Endurance training has been shown to be effective in treating adolescents with major depressive disorder (MDD). To integrate endurance training into the therapeutic setting and the adolescents' daily lives, the current performance status of the adolescents should be accurately assessed. This study aims to examine adolescents with MDD concerning exhaustion criteria during a cardiopulmonary exercise test (CPET), as well as to compare the values obtained thereon with sex- and age-related control values. The study included a retrospective examination of exhaustion criteria ((i) oxygen consumption (V̇O2) plateau, (ii) peak respiratory exchange ratio (RERpeak) > 1.0, (iii) peak heart rate (HRpeak) ≥ 95% of the age-predicted maximal HR, and (iv) peak blood lactate concentration (BLCpeak) > 8.0 mmol⋅L-1) during a graded CPET on a cycle ergometer in adolescents with MDD (n = 57). Subsequently, maximal V̇O2, peak minute ventilation, V̇O2 at the first ventilatory threshold, and peak work rate of participants who met at least two of four criteria were compared with published control values using an independent-sample t-test. Thirty-three percent of the total population achieved a V̇O2 plateau and 75% a RERpeak > 1.0. The HR and BLC criteria were met by 19% and 22%, respectively. T-test results revealed significant differences between adolescents with MDD and control values for all outcomes. Adolescents with MDD achieved between 56% and 83% of control values.   Conclusions: The study shows that compared with control values, fewer adolescents with MDD achieve the exhaustion criteria on a CPET and adolescents with MDD have significantly lower cardiorespiratory fitness.   Clinical trial registration: No. U1111-1145-1854. What is Known: • It is already known that endurance training has a positive effect on depressive symptoms. What is New: • A relevant proportion of adolescents with major depressive disorder do not achieve their V̇O2max during a graded cardiopulmonary exercise test. • Adolescents with major depressive disorder have significantly lower cardiorespiratory fitness compared to sex- and age-related control values.

The aerobic capacity - fatigue relationship in persons with Multiple Sclerosis is not reproducible in a pooled analysis of two randomized controlled trials.

BACKGROUND: Fatigue is one of the most frequent symptoms of persons with Multiple Sclerosis (pwMS) but has limited treatment options. Aerobic capacity and endurance training have been discussed as relevant factors to improve fatigue. However, over the last decades, results have been equivocal. This secondary analysis of two pooled parallel group RCTs of three weeks of endurance training (high intensity interval training (HIIT) and moderate continuous training (MCT)) for pwMS aimed to (I) reproduce reported associations between aerobic capacity and fatigue on a cross-sectional and interventional level. The analysis further aimed to (II) investigate intervention effects on fatigue in a severely fatigued subgroup and (III) analyze differences in changes of fatigue between peak oxygen uptake (VO2peak) responders and non-responders. METHODS: Both RCTs were conducted in the same inpatient rehabilitation clinic in Valens, Switzerland. Original primary outcomes were cognitive function (RCT1) and change in proportion of circulating regulatory T-cells (RCT2). PwMS (n = 131) with a relapsing-remitting or secondary progressive MS phenotype and Expanded Disability Status Scale score between 1 - 6.5 were eligible. Over the two studies participants exercised 3 - 5 times per week on cycle ergometers at intensities of 65 - 70% of maximum heart rate (HRmax) for 30 min (MCT groups) or three times per week with five 90 - 180 s intervals at intensities of 85% - 100% of HRmax and 90 s rest intervals (HIIT groups). Main outcome measures for the present secondary analysis were VO2peak measured during a cardiopulmonary exercise test and the Fatigue Scale for Motor and Cognitive Functions (FSMC), both assessed at the start and end of inpatient rehabilitation. RESULTS: Baseline correlations did not reveal a significant association between VO2peak and FSMC. There were no significant improvements in fatigue after the HIIT and MCT in the overall sample or the subsample of severely fatigued pwMS and no significant differences in fatigue changes between VO2peak-responders and non-responders. CONCLUSIONS: Our analysis did not confirm the aerobic capacity - fatigue relationship on a cross-sectional and experimental level, even when analyzing subgroups that should benefit the most according to proposed hypotheses.

Do baseline cognitive status, participant specific characteristics and EDSS impact changes of cognitive performance following aerobic exercise intervention in multiple sclerosis?

PURPOSE: Cognitive impairment is a common symptom of multiple sclerosis (MS). Physical exercise represents a promising non-pharmacological therapy option, however, potential predictors for successful cognitive improvements mediated by exercise remain to be elucidated in order to optimize targeted exercise training regimens. One of the most promising exercise training regime in this context is high-intensity interval training (HIIT). Against this backdrop, this study i) analysed the effects of a three-week HIIT compared to moderate continuous exercise on cognitive performance and ii) investigated potential predictors for changes of cognitive performance following a three-week aerobic exercise intervention. METHODS: Datasets of two randomized controlled trials (RCT) were pooled, resulting in a total sample size of n = 130 persons with MS (pwMS) who either performed HIIT or moderate intensity continuous (MCT) exercise 3-5x/ week for three weeks. Cognitive performance was assessed with the Brief International Cognitive Assessment for MS. I) Potential within (time) and interaction (time x group) effects for cognitive performance were investigated with univariate analyses of covariance (ANCOVA). II) Potential predictors for changes of cognitive performance were assessed by multiple linear regression models. RESULTS: ANCOVA revealed significant time effects for all cognitive outcomes and a time x group interaction for verbal learning (p=.045), with HIIT inducing superior effects compared to moderate continuous exercise (MCT). Cognitive status (impaired/intact cognition) (p= .008) and exercise regime (HIIT/moderate continuous) (p=.040) influenced changes of verbal learning. Cognitive status (p=.006) and EDSS (p=.048) affected changes of visuospatial memory in pwMS. The models accounted for 5.4% and 7.7% of the variance. CONCLUSION: Cognitive status, exercise regime and EDSS potentially impact changes of specific cognitive domains following aerobic exercise. Further predictors for changes of cognitive performance following an aerobic exercise intervention need to be investigated as current results accounted only for a limited amount of variance. RCTs that investigate effects of physical exercise on cognitive performance should include only pwMS with impaired baseline cognitive performance. To better understand the impact of exercise on cognitive performance, it is furthermore recommendable to include cognitive assessments in clinical routine.

Cellular immune response to acute exercise: Comparison of endurance and resistance exercise.

OBJECTIVES: Exercise-induced cellular mobilization might play a role in treatment and prevention of several diseases. However, little is known about the impact of different exercise modalities on immune cell mobilization and clinical cellular inflammation markers. Therefore, the present study aimed to investigate differences between acute endurance exercise (EE) and resistance exercise (RE) on cellular immune alterations. METHODS: Twenty-four healthy men conducted an acute EE (cycling at 60% of peak power output) and RE (five exercise machines at 70% of the one-repetition maximum) session lasting 50 minutes in randomized order. Blood samples were collected before, after and one hour after exercise cessation. Outcomes included counts and proportions of leukocytes, neutrophils (NEUT), lymphocytes (LYM), LYM subsets, CD4/CD8 ratio, and the clinical cellular inflammation markers NEUT/LYM ratio (NLR), platelets/LYM ratio (PLR), and systemic immune inflammation index (SII). RESULTS: Alterations in all outcomes were revealed except for CD8+ T cells, CD4/CD8 ratio, NLR, and PLR. EE induced a stronger cellular immune response and provoked alterations in more immune cell populations than RE. SII was altered only after EE. CONCLUSION: An acute EE session causes a stronger mobilization of immune cells than RE. Additionally, SII represents an integrative marker to depict immunological alterations.