Changes In Cardiorespiratory Fitness Research Articles

ARE THERE NON-RESPONDERS TO HIIT IN CANCER SURVIVORS? CHANGES IN CARDIORESPIRATORY FITNESS, BODY COMPOSITION AND SYSTEMIC INFLAMMATION

INTRODUCTION High intensity interval training (HIIT) has been shown to elicit significant improvements in VO2peak in cancer survivors. Only 46-60% of healthy individuals are reported to respond to exercise interventions, though this rate has not been investigated in cancer survivors. AIMS: To determine the response rate in cancer survivors over 28-weeks of HIIT as measured by changes in cardiorespiratory fitness. Secondarily, the study aimed to observe associations between changes in cardiorespiratory fitness, body composition and inflammatory markers. METHODS 131 survivors of breast, prostate or colorectal cancer were observed over 28-weeks of HIIT (4x4 minutes; 85-95% HRpeak). VO2peak, body composition and markers of systemic inflammation were assessed at baseline, four-, 16- and 28-weeks. An improvement in VO2peak of 3.5 ml.kg-1.min-1 was used as a standard of minimal clinically important difference (MCID). Body composition was measured using DEXA, and inflammatory markers were assessed for each timepoint. RESULTS 59.6% of participants improved their VO2peak greater than MCID (+3.5 ml.kg-1.min-1) and these individuals were retrospectively classified as responders. Responders showed improvements in VO2peak at four- and 16-weeks and maintained this change through to 28-weeks (0-4 weeks: +2.92 ml.kg-1.min-1, p<0.001; 0-16 weeks: +5.70 ml.kg-1.min-1, p<0.001; and 0-28 weeks: +5.30 ml.kg-1.min-1, p<0.001). No significant change in VO2peak was seen in non-responders (40.4%). Time since treatment, cancer type, and cancer treatment were all found to contribute to a model predicting VO2peak change (R=0.464, R2 = 21.5%., adj R2=16.1%, p<0.001). Body composition and inflammatory markers improved in response to training however were not associated with VO2peak change. CONCLUSIONS HIIT elicited a MCID in VO2peak in almost 60% of cancer survivors. Independent to VO2peak change and cancer type, survivors showed significant favourable changes in inflammation and body composition in response to training.

Long-Term Improvement in Cardiorespiratory Fitness Ameliorates Insulin Sensitivity beyond Changes in Visceral/Ectopic Fat among Men with Visceral Obesity

The SYNERGIE study documented the effects on cardiometabolic risk (CMR) indices of a 1-year lifestyle intervention targeting physical activity (PA) and diet followed by a 2-year maintenance period in men with visceral obesity. Improvements in CMR markers and a decrease in low-attenuation muscle (LAM) area were observed after 1 year. Despite a rebound in visceral adipose tissue (VAT) during the maintenance period, insulin resistance (IR) improved. We tested the hypothesis that variations in cardiorespiratory fitness (CRF) and LAM could explain the long-term improvement in IR. A health (n = 88; mean age 49.0 ± 8.2 years) and fitness (n = 72) evaluation was performed at 0, 1, and 3 years. Participants were classified into two groups based on their CRF response over the maintenance period (worsening: CRF− vs. maintenance/improvement: CRF+). During the maintenance period, changes in the psoas and core LAM areas correlated with changes in IR (r = 0.27; p < 0.05 and r = 0.34; p < 0.005) and changes in CRF (r = −0.31; p < 0.01 and r = −0.30; p < 0.05). IR improved in the CRF+ group (p < 0.05) but remained stable in the CRF− group. Men in the CRF+ group regained half of the changes in VAT volume and LAM at the psoas and mid-thigh compared to the CRF− group (p < 0.05). These results support the importance of targeting VAT and CRF/PA for the long-term management of CMR in men with visceral obesity.

WEB OF TRANSFORMATIONS: impact of multicomponent intervention on the relationship between sociodemographic indicators, changes in body composition, cardiorespiratory fitness and biochemical markers in adolescents with overweight and obesity

ABSTRACT The study aims to analyze the relationships between changes after multicomponent intervention in sociodemographic indicators, body composition, cardiorespiratory fitness and biochemical markers in overweight/obese adolescents. Quasi-experimental study with 33 overweight/obese adolescents (17 in the intervention group (IG) and 16 in the control group (16)), in which the GI participated in the multicomponent intervention for 24 weeks. Sociodemographic indicators, body composition, cardiorespiratory fitness and biochemical markers were evaluated. Network analysis was performed using JASP software. In GI, the reduction in %BF proved to be the variable with greater connectivity and strength in the network compared to the control network. Changes in %BF were related to changes in ACR, BMI and leptin. It is concluded that the reduction in %BF is the most important variable in network relationships after the intervention, suggesting that the greater the reduction in %BF, the greater the effect on variables such as BMI, ACR and leptina.

Independent and joint associations of estimated cardiorespiratory fitness and its dynamic changes and obesity with the risk of hypertension: A prospective cohort.

Our aim was to examine the independent and joint associations of estimated cardiorespiratory fitness (CRF) and its changes and obesity with risk of hypertension in a rural Chinese population. A prospective cohort including 9848 adults without hypertension at baseline was enrolled. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were estimated by logistic regression models. Restricted cubic splines were used to model the dose-response relationship. During 6 years follow-up, 2,019 individuals developed hypertension. A negative association between estimated CRF and hypertension incidence was observed, with the risk being 0.87 (0.84-0.90) per MET increment. For estimated CRF change, the risks of hypertension were 1.50 (1.27-1.77) and 0.75 (0.59-0.97) for decreasers and increasers, respectively, compared to maintainers. Joint analyses showed individuals in the overweight/obesity-fourth quartile of estimated CRF had a 2.08 times higher risk of hypertension than those in the normal weight-first quartile (Pinteraction < 0.05). Those overweight/obesity-decreasers had the highest risk (OR: 2.19, 95%CI: 1.71-2.81; Pinteraction < 0.05) compared to the normal-maintainers. Similar results for abdominal obesity were also observed. Estimated CRF and its dynamic changes showed a negative association with hypertension incidence in the rural Chinese population.

Effect of Adding a Program of Contextualized, Personalized, Remote Physical Activity Support to Conventional Cardiac Rehabilitation.

The objective of this investigation was to conduct a randomized controlled trial to evaluate whether KiActiv Heart alongside usual care (UC) promotes positive physical activity (PA) change versus UC alone. Patients in cardiac rehabilitation (n = 130) undertook an 8-wk intervention with follow-up at wk 8. Both groups attended UC and wore a PA monitor during the intervention. The intervention group accessed the digital service and received weekly one-to-one remote mentor sessions. The primary outcome was change in PA to achieve the Association of Certified Physiotherapists in Cardiac Rehabilitation (ACPICR) recommendations. The secondary outcome was cardiorespiratory fitness (CRF) change, measured using incremental shuttle walk test (ISWT). The probability of meeting ACPICR "Daily Activity" recommendation was statistically significantly greater in the intervention group versus control at wk 8 (P < .05). No statistically significant differences between groups were found for mean ISWT change (intervention 89 ± 116 m; control 44 ± 124 m). Participation in KiActiv Heart alongside UC was associated with statistically significant improvement in probability of meeting ACPICR recommendation and non-statistically significant but potentially clinically important increases in CRF versus UC alone. This builds on existing evidence for effectiveness.

Early reduction in cardiorespiratory fitness and diastolic reserve following radiation therapy for lung cancer

BackgroundContemporary radiotherapy for the treatment of lung cancer is effective in targeting tumor tissue while limiting heart exposure, yet cardiac toxicity still occurs, often becoming clinically apparent years later. Cardiorespiratory fitness (CRF) is an independent predictor of cardiovascular, cancer-related, and overall mortality and may serve as a sensitive measure of subclinical cardiac toxicity following anti-cancer treatments. Prior work has demonstrated a significant relationship between reduced CRF and impaired left-ventricular (LV) diastolic reserve in cancer survivors following thoracic radiotherapy. The purpose of this study was to assess early longitudinal changes in CRF and cardiac function in patients with lung cancer following radiotherapy.MethodsTen patients (69 [61–76] years, 70% female) with lung cancer without known cardiovascular disease scheduled to receive radiotherapy involving a clinically-relevant heart dose (≥ 5 Gy to > 10% of heart volume) were evaluated prior to and following treatment. Changes in CRF (peak oxygen consumption [VO2peak], oxygen uptake efficiency slope [OUES]), cardiac function (LV ejection fraction [LVEF], rest and exercise diastolic function [diastolic functional reserve index (DFRI)]), cardiac biomarkers (N-terminal pro-brain natriuretic peptide [NT-proBNP], high-sensitivity C-reactive protein [hsCRP]), and health-related quality of life (HRQOL; Functional Assessment of Cancer Therapy-General-7 [FACT-G7]) were measured.ResultsThe VO2peak was reduced at baseline (1.245 [0.882–1.605] L·min− 1; 70 [62–86] %-predicted) and significantly declined (1.095 [0.810–1.448] L·min− 1, P = 0.047; 62 [56–76] %-predicted, P = 0.005) at 6.0 [3.0–6.0] months post-radiotherapy. Similarly, a significant decline in the OUES was observed (1.63 [1.27–1.88] to 1.57 [1.12–1.75], P = 0.032). Systolic cardiac function was normal at baseline and did not change following radiotherapy (LVEF; 62 [56–65]% to 66 [57–68]%, P = 0.475). The DFRI significantly declined following radiotherapy (34.9 [22.7–41.6] vs. 12.8 [3.1–35.9]). The hsCRP increased significantly from 4.4 [1.4–5.8] to 6.1 [3.7–20.7] g/L, P = 0.047 with a trend towards higher levels of NT-proBNP (65 [49–125] to 121 [88–191] pg/mL, P = 0.110). Health-related quality of life significantly decreased (FACT-G7; 21.5 [18.8–25] to 15.5 [11.5–20]; P = 0.021) post-radiotherapy.ConclusionsPatients with lung cancer receiving radiotherapy with a clinically-significant heart dose experience reductions in CRF (VO2peak, OUES) as early as six months following treatment with concurrent reductions in diastolic reserve (DFRI), HRQOL, and increases in cardiac biomarkers (NT-proBNP, hsCRP).

Cardiorespiratory fitness and metabolic risk in Chinese population: evidence from a prospective cohort study

BackgroundStudies on the association between estimated cardiorespiratory fitness (CRF) and changes in metabolic risk in the Chinese population are limited. This study aims to examine the associations between CRF and changes in metabolic risk.Subjects and methodsWe included 4,862 and 2,700 participants recruited from 28 provinces in the China Health and Retirement Longitudinal Study (CHARLS) in the baseline (Wave 1) and follow-up (Wave 4) analyses, respectively. CRF was calculated using sex-specific longitudinal non-exercise equations. Metabolic indicators included systolic blood pressure (SBP), diastolic blood pressure (DBP), triglyceride (TG), high-density lipoprotein cholesterol (HDL-C), and fasting plasma glucose (FPG) levels. The metabolic score was calculated as the number of changes in the above metabolic indicators above the 75th percentile of the distribution of changes (equal to or below the 25th percentile for HDL-C).ResultsIn the baseline analysis, CRF was negatively associated with SBP, DBP, TG, and FPG, and positively correlated with HDL-C after adjusting for age, smoking status, and drinking status (all P < 0.0001) in both males and females. In the follow-up analysis, higher baseline CRF was significantly related to a decrease in SBP, DBP, TG, FPG, and metabolic score (all P < 0.0005), and increased HDL-C (P < 0.0001) after further adjustment for corresponding baseline metabolic indicators. The associations remained significant after stratification by sex, except for the changes in HDL-C levels in females. Furthermore, improved CRF was associated with favorable changes in DBP, TG, HDL-C, FPG, and metabolic scores in all populations and males. Significant associations between changes in CRF and DBP, TG, and FPG levels were found in females.ConclusionHigher baseline CRF and improved CRF were associated with favorable changes in metabolic indicators.

Cardiorespiratory Fitness and Risk of Heart Failure with Preserved Ejection Fraction.

Preventive strategies for heart failure (HF) with preserved ejection fraction (HFpEF) include pharmacotherapies and lifestyle modifications. However, the association between cardiorespiratory fitness (CRF) assessed objectively by a standardized exercise treadmill test (ETT) and the risk of HFpEF has not been evaluated. Thus, we evaluated the association between CRF and HFpEF incidence. We assessed CRF in US Veterans (624,551 men; mean age 61.2 ± 9.7 years and 43,179 women; mean age 55.0±8.9 years) by a standardized ETT performed between 1999-2020 across US Veterans Affairs Medical Centers. All had no evidence of HF or myocardial infarction prior to completion of the ETT. We assigned participants to one of five age-and-gender-specific CRF categories (quintiles) based on peak metabolic equivalents (METs) achieved during the ETT and four categories based on CRF changes in those with two ETT evaluations (n=139,434) ≥1.0 year apart. During the median follow-up of 10.1 years (IQR 6.0-14.3 years), providing 6,879,229 person-years, there were 16,493 HFpEF events with an average annual rate of 2.4 events per 1,000 person-years. The adjusted risk of HFpEF decreased across CRF categories as CRF increased, independent of comorbidities. For fit individuals (≥10.5 METs) the hazard ratio (HR) was 0.48 (95% CI 0.46-0.51) compared with least fit (≤ 4.9 METs; referent). Being unfit carried the highest risk (HR, 2.88; 95% CI, 2.67-3.11) of any other comorbidity. The risk of unfit individuals who became fit was 37% lower (HR 0.63, 95% CI 0.57-0.71), compared to those who remained unfit. Higher CRF levels are independently associated with lower HRpEF in a dose-response manner. Changes in CRF reflected proportional changes in HFpEF risk, suggesting that the HFpEF risk was modulated by CRF. This article is protected by copyright. All rights reserved.

Modifiable Physical Factors That Influence Physical Function for People Receiving Peritoneal Dialysis

People receiving peritoneal dialysis experience physical function decline, impairing their ability to complete everyday activities, leading to poorer quality of life. Physical factors, including cardiorespiratory fitness, muscle strength, physical activity, and sedentary behavior are associated with physical function. However, little is known about this relationship, or temporal changes of these factors in this cohort. This study aimed to explore modifiable physical factors that are associated with physical function, identify which factor has the strongest influence, and explore temporal changes. Adults receiving peritoneal dialysis underwent objective and self-reported physical function, cardiorespiratory fitness, muscle strength, physical activity and sedentary behavior assessments 3 times over a 12-month observation period (at baseline, 6 months, and 12 months). Eighty-two participants underwent assessments. All modifiable physical factors were predominantly moderate to strongly associated with physical function at baseline. Cardiorespiratory fitness had the strongest and most consistent influence with every meter conferring a 0.08-unit (P< 0.01) and 0.01-unit (P< 0.05) increase in self-report and objective physical function score, respectively. Temporal changes were observed for modifiable physical factors with significant mean changes in cardiorespiratory fitness (-9.8%), quadricep strength (-5%), moderate-to-vigorous (-25.9%) and total (-16.2%) physical activity, and sedentary behavior (+7.1%). The results of this study indicate that cardiorespiratory fitness could be routinely monitored to detect risk of physical function decline and targeted through intervention to enhance physical function for people receiving peritoneal dialysis. Nevertheless, all factors should be considered when designing interventions to mitigate temporal changes and induce the numerous health benefits offered by being physically active.

Association between change in cardiorespiratory fitness and prostate cancer incidence and mortality in 57 652 Swedish men

ObjectivesTo examine the associations between changes in cardiorespiratory fitness (CRF) in adulthood and prostate cancer incidence and mortality.MethodsIn this prospective study, men who completed an occupational health profile assessment including...

Molecular mechanisms underpinning favourable physiological adaptations to exercise prehabilitation for urological cancer surgery.

Surgery for urological cancers is associated with high complication rates and survivors commonly experience fatigue, reduced physical ability and quality of life. High-intensity interval training (HIIT) as surgical prehabilitation has been proven effective for improving the cardiorespiratory fitness (CRF) of urological cancer patients, however the mechanistic basis of this favourable adaptation is undefined. Thus, we aimed to assess the mechanisms of physiological responses to HIIT as surgical prehabilitation for urological cancer. Nineteen male patients scheduled for major urological surgery were randomised to complete 4-weeks HIIT prehabilitation (71.6 ± 0.75 years, BMI: 27.7 ± 0.9 kg·m2) or a no-intervention control (71.8 ± 1.1 years, BMI: 26.9 ± 1.3 kg·m2). Before and after the intervention period, patients underwent m. vastus lateralis biopsies to quantify the impact of HIIT on mitochondrial oxidative phosphorylation (OXPHOS) capacity, cumulative myofibrillar muscle protein synthesis (MPS) and anabolic, catabolic and insulin-related signalling. OXPHOS capacity increased with HIIT, with increased expression of electron transport chain protein complexes (C)-II (p = 0.010) and III (p = 0.045); and a significant correlation between changes in C-I (r = 0.80, p = 0.003), C-IV (r = 0.75, p = 0.008) and C-V (r = 0.61, p = 0.046) and changes in CRF. Neither MPS (1.81 ± 0.12 to 2.04 ± 0.14%·day-1, p = 0.39) nor anabolic or catabolic proteins were upregulated by HIIT (p > 0.05). There was, however, an increase in phosphorylation of AS160Thr642 (p = 0.046) post-HIIT. A HIIT surgical prehabilitation regime, which improved the CRF of urological cancer patients, enhanced capacity for skeletal muscle OXPHOS; offering potential mechanistic explanation for this favourable adaptation. HIIT did not stimulate MPS, synonymous with the observed lack of hypertrophy. Larger trials pairing patient-centred and clinical endpoints with mechanistic investigations are required to determine the broader impacts of HIIT prehabilitation in this cohort, and to inform on future optimisation (i.e., to increase muscle mass).

Interindividual response variation to exercise-based cardiac rehabilitation on changes in cardiorespiratory fitness in heart transplant patients: A secondary meta-analysis of randomized controlled trials

PurposeDetermine whether true inter-individual exercise response differences (IIRD) occur in cardiorespiratory fitness (CRF) as a result of exercise-based cardiac rehabilitation in heart transplant patients. MethodsUsing data from a recent (2023) meta-analysis of nine RCTs representing 296 patients (163 exercise, 133 control), an aggregate data meta-analysis of treatment effects (change outcome differences between exercise and control groups) was conducted as well as an IIRD meta-analysis using the inverse variance heterogeneity (IVhet) model. The primary outcome was cardiorespiratory fitness (VO2max) in mL.kg-1.min-1. ResultsStatistically significant and clinically important increases equivalent to 14.5% were observed for VO2max in mL.kg-1.min-1 (X̅, 3.0, 95% CI, 2.4 to 3.7 mL.kg-1.min-1, p <0.001; Q=11.8, p=0.16; I2=32.0%, 95% CI, 0% to 68.8%; τ2=0.4). The 95% prediction interval (PI) was 1.2 to 4.7 mL.kg-1.min-1. However, no statistically significant IIRD were observed (X̅, 0.6, 95% CI, -1.1 to 1.4 mL.kg-1.min-1; τ2=2.9). The 95% PI was -2.7 to 2.8 mL.kg-1.min-1. ConclusionsWhile exercise-based cardiac rehabilitation increases VO2max in mL.kg-1.min-1 in heart transplant patients, a lack of true exercise-associated IIRD exist. A need exists for additional well-designed randomized controlled trials of longer duration to determine the long-term effects of exercise-based cardiac rehabilitation on VO2max in mL.kg-1.min-1 among heart transplant patients.

Preliminary Effects of Aerobic Exercise, Training Dose, and Cardiorespiratory Fitness on Resting Plasma Neurotrophic Factors in Alzheimer’s Dementia in the FIT‐AD Trial

AbstractBackgroundVascular factors are increasingly recognized for their roles in the pathogenesis and progression of Alzheimer’s dementia (AD). Cardiorespiratory fitness (CRF), a physiologic indicator of cardiovascular health, and plasma neurotrophic factors, endogenous soluble proteins in the periphery, have been linked to cognition, brain structure and function, and AD and are modifiable by aerobic exercise (AEx), but their interplay remains poorly understood. The objective of this pilot study was to estimate the effect sizes of 6‐month AEx on resting plasma neurotrophic factors and the relationships of CRF and exercise dose with change in resting plasma neurotrophic factors in AD.MethodThis study was a pilot blood ancillary study of the FIT‐AD Trial that randomized participants to 6‐month AEx or stretching control on a 2:1 allocation ratio. The blood study enrolled 26 participants (AEx Group [n = 18] and stretching control [n = 8]). Resting plasma brain‐derived neurotrophic factor (BDNF), irisin, fibroblast growth factor‐21 (FGF‐21], and insulin‐like growth factor‐1 (IGF‐1), and CRF (peak oxygen consumption) were assessed at baseline, 3 and 6 months. Exercise dose was calculated by the heart rate physical activity score (HRPAS) method.ResultThe sample was 77.6±6.99 years of age and had 15.4±3.00 years of education on average. Sixty‐five percent of the participants were male and 96.2% carried at least one copy of APOE e4. Most 6‐month between‐group effect sizes were small except for irisin (d = ‐0.44), indicating that the irisin levels decreased in the AEx group relative to stretching control. The association between exercise dose and changes in CRF with changes in neurotrophic biomarker were weak (r2 ≤ 0.025).ConclusionThe effects of exercise on BDNF, irisin, IGF‐1, and FGF‐21 may be heterogeneous in AD. Weak associations of exercise dose and CRF changes with changes in resting neurotrophic biomarkers were seen. There were weak associations of exercise dose and CRF changes with changes in resting neurotrophic biomarkers. Our findings need to be validated in future, adequately powered exercise studies in AD.

Are changes in muscular strength following head‐down bed rest independently associated with improved cognitive function in older adults? A secondary analysis of a randomized controlled trial

AbstractBackgroundPhysical inactivity is common among older adults and is a risk factor for cognitive decline. Even a brief period of physical inactivity, such as bed rest due to hospitalization, in older adults has significant negative impacts. Exercise is strategy to counter the negative effects of physical inactivity. Exercise‐induced improvements in cardiorespiratory fitness is associated with improved cognitive function. Less is known regarding the contribution of exercise‐induced changes in muscle strength to changes in cognitive function. Thus, we aimed to examine the independent contribution of: 1) change in cardiorespiratory fitness; and 2) change in peak muscle torque of the lower extremity to changes in cognitive function in a randomized controlled trial (RCT) of head‐down bed rest (HDBR) vs. HDBR with exercise in healthy older adults.MethodAn analysis of a non‐blinded, parallel‐group, RCT of 22 healthy older adults (11 males and 11 females) aged 55‐65 years. Participants were randomized to: 1) 14 days of 6° HDBR (CON); or 2) HDBR with daily resistance and aerobic exercise training (EX). Outcome measures were taken at baseline and HDBR completion. The Flanker Inhibitory Control and Attention Task measured executive function. Physical fitness measures included: 1) maximal aerobic capacity (VO2max) using a bicycle ergometry test; and 2) knee extension isokinetic muscular strength (KE) using a Biodex dynamometer. We performed two separate multiple linear regressions to determine whether following 14 days of HDBR: 1) VO2max was associated with Flanker score, after accounting for ΔKE; and 2) KE was associated with Flanker score, after accounting for ΔVO2max. Each model was also adjusted for baseline Flanker score and the baseline physical fitness measure of interest.ResultAt baseline, average Flanker t‐score was 48.33, mean VO2max was 32.527 ml/kg/min, and knee extension strength was 64.472 Nm. VO2max at follow‐up was not significantly associated with Flanker performance (b = 0.232 ± 0.716; p = 0.635; R2 adj. = 0.285). However, greater KE strength was significantly associated with better Flanker performance (b = 2.023 ± 0.389; p = 0.043; R2 adj. = 0.633) at HDBR completion.ConclusionThe maintenance of muscle strength even during brief periods of physical inactivity appears to be critical for cognitive health in older adults.

Aerobic exercise and volumetric change in the human hippocampus: A meta‐analysis of randomized controlled trials in healthy older individuals

AbstractBackgroundThere is promising, albeit equivocal, evidence that aerobic exercise training (AET) increases human hippocampal volume. The evidence is unclear, as recent randomized controlled trials (RCTs) have failed to replicate AET’s previously reported favorable effects on hippocampal volume in cognitively unimpaired older individuals. We thus conducted a meta‐analysis of RCTs investigating the effects of AET on hippocampal volume and cardiorespiratory fitness (CRF) in cognitively unimpaired, healthy older individuals.MethodA meta‐analysis of RCTs that delivered AET interventions to older individuals. Inclusion criteria were: 1) cognitively unimpaired, healthy individuals aged ≥ 50; 2) AET intervention delivered for at least four weeks; 3) at least one intervention group and one control group; 4) reported data of the effects of AET on hippocampal volume. Two authors independently screened titles, abstracts, and full texts, performed data extraction and methodological quality assessment of included studies. We performed meta‐analyses with random‐effects robust variance estimation models and meta‐regression analyses to test associations between changes in CRF and hippocampal volume. The primary outcome was changes in hippocampal volume, and the secondary outcome was changes in CRF.ResultEight parent trials and one secondary outcome article were eligible. The meta‐analytic summary of 17 effect sizes indicated no significant effects of AET on hippocampal volume (SMD = 0.10, 95%CI ‐0.01 to 0.21, p = 0.073). Meta‐analysis of nine studies and effect sizes showed that AET moderately improved cardiorespiratory fitness (SMD = 0.30, 95%CI 0.12 to 0.48, p = 0.005). Improvement in CRF was not statistically associated with changes in hippocampal volume (bSE = 0.05, SE = 0.51, p = 0.923). Methodological quality was poor in one, fair in three, good in four, and excellent in one trial.ConclusionAET did not show robust effects on hippocampal volume in cognitively unimpaired, healthy older individuals. Since AET significantly improved CRF, a lack of training fidelity is unlikely to explain our findings. The biologically still plausible favorable effects of AET on hippocampal volume in cognitively unimpaired older individuals might be masked by methodological weaknesses and the inclusion of only nine studies. Future studies need to address: the lack of harmonization of hippocampus quantification methods and insufficient power to detect meaningful changes in hippocampal volume across studies.

A pilot study to assess the feasibility of a remotely monitored high-intensity interval training program prior to allogeneic hematopoietic stem cell transplantation.

Although allogeneic hematopoietic stem cell transplantation (HCT) can be a curative therapy for hematologic disorders, it is associated with treatment-related complications and losses in cardiorespiratory fitness and physical function. High-intensity interval training (HIIT) may be a practical way to rapidly improve cardiorespiratory fitness and physical function in the weeks prior to HCT. The primary aim of this study was to assess the feasibility of implementing a pre-HCT home-based HIIT intervention. The secondary aim was to evaluate pre to post changes in cardiorespiratory fitness and physical function following the intervention. This was a single-arm pilot study with patients who were scheduled to undergo allogeneic HCT within six months. Patients were instructed to complete three 30-minute home-based HIIT sessions/week between the time of study enrollment and sign-off for HCT. Sessions consisted of a 5-minute warm-up, 10 high and low intervals performed for one minute each, and a 5-minute cool-down. Prescribed target heart rates (HR) for the high- and low-intensity intervals were 80-90% and 50-60% of HR reserve, respectively. Heart rates during HIIT were captured via an Apple Watch and were remotely monitored. Feasibility was assessed via retention, session adherence, and adherence to prescribed interval number and intensities. Paired t-tests were used to compare changes in fitness (VO2peak) and physical function [Short Physical Performance Battery (SPPB), 30-second sit to stand, and six-minute walk test (6MWT)] between baseline and sign-off. Pearson correlations were used to determine the relationship between intervention length and changes in cardiorespiratory fitness or functional measures. Thirteen patients (58.8±11.6 years) participated in the study, and nine (69.2%) recorded their training sessions throughout the study. Median session adherence for those nine participants was 100% (IQR: 87-107). Adherence to intervals was 92% and participants met or exceeded prescribed high-intensity HR on 68.8±34.8% of intervals. VO2peak improved from baseline to sign-off (14.6±3.1 mL/kg/min to 17.9±3.3 mL/kg/min; p<0.001). 30-second sit to stand and SPPB chair stand scores significantly improved in adherent participants. Improvements in 30-second sit to stand (13.8±1.5 to 18.3±3.3 seconds) and 6MWT (514.4±43.2 to 564.6±19.3) exceeded minimal clinically important improvements established in other chronic disease populations, representing the minimum improvement considered meaningful to patients. Findings demonstrate that implementing a pre-HCT home-based remotely monitored HIIT program is feasible and may provide benefits to cardiorespiratory fitness and physical function.

The effect of mild to moderate COVID-19 infection on the cardiorespiratory fitness of firefighters.

An adequate level of cardiorespiratory fitness (CRF) is critical for firefighters to perform the strenuous and physiologically demanding work of firefighting safely and effectively. The coronavirus disease 2019 (COVID-19) has been shown to negatively impact CRF in both the acute phase and longer-term following infection. This study aimed to determine changes to the CRF of firefighters pre- to post-mild to moderate COVID-19 infection and to investigate the impact of days past COVID-19 infection on change in CRF. CRF measures from cardiopulmonary exercise testing (CPET) at annual occupational health exams that occurred pre-COVID-19 infection in 2019 were obtained for firefighters from seven Arizona fire departments. Measures were compared to CPET evaluations from annual health exams the following year in a cohort of firefighters who self-reported mild to moderate illness following COVID-19 infection between exams. Among a cohort of 103 firefighters, mean age 40 ± 9 years, CRF [as measured by peak oxygen consumption (VO2)] declined by an average of 2.55 ml·kg-1·min-1 or 7.3% (d = -0.38, p < 0.001) following COVID-19 infection (mean time from COVID-19 infection to CPET was 110 ± 78 days). The number of days past COVID-19 infection showed a small, yet significant, relationship to peak VO2 (r = 0.250, p = 0.011). Estimated marginal effects indicated that when biological sex, age, and BMI are controlled for, predicted peak VO2 returned to pre-COVID-19 values ~300 days after COVID-19 infection. Peak VO2 (ml·kg-1·min-1) declined 7.3% among firefighters an average of 110 days past reporting mild to moderate COVID-19 infection. This decrease has implications for the operational readiness and safety of firefighters.

Maintaining or increasing cardiorespiratory fitness is associated with reduced hospital admission rate.

The aim of this study was to investigate the association between change in cardiorespiratory fitness (CRF) and cardiovascular disease (CVD)-related and all-cause hospital admission and explore if the association varies dependently on prior admission, baseline CRF, sex, and age. A total of 91 140 adult participants (41.5% women) with two examinations from occupational health profile assessments between 1986 and 2019 were included (mean of 3.2 years between examinations). Cardiorespiratory fitness was assessed as maximal oxygen consumption and estimated through a submaximal cycle test. Cardiorespiratory fitness change was defined as annual percentage change in relative CRF (mL/min/kg) and further divided into 'decliners' (≤1%), 'maintainers' (-1% to 1%), and 'increasers' (>1%). Hospital admissions were followed over a mean of 7 years. Natural cubic splines and Cox proportional hazards model were applied. Additionally, prevented fraction for the population was calculated. Increase in CRF was associated with a lower risk of CVD [hazard ratio (HR) = 0.99] and all-cause hospital admission (HR = 0.99), after multilevel adjustment for confounders and change in smoking, diet, and stress. Compared with a decline, maintenance of CRF was associated with 9% and 7% lower risk of CVD and all-cause admission, respectively. Increase in CRF reduced the risk by 13% and 11% and, for individuals with prior admission, by 20% and 14%. The burden of CVD and all-cause admission was 6% and 5% lower than if the whole cohort had declined CRF, with large potential cost savings. Efforts to maintain or improve CRF should be included in disease-preventive strategies, regardless of change in other lifestyle-related risk factors. Preventing the age-associated decline in CRF can lessen healthcare utilization and costs.

Differential response to interleukin-1 blockade with anakinra on cardiorespiratory fitness in patients with heart failure with preserved ejection fraction stratified according to ejection fraction

Abstract Background Patients with heart failure with preserved ejection fraction (HFpEF) are a heterogeneous clinical population and might respond differently to pharmacologic therapies based on their baseline left ventricular EF (LVEF) (50-59% vs. ≥60%). Interleukin-1 (IL-1) is a key pro-inflammatory cytokine being explored as a therapeutic target in HFpEF for its effects on numerous outcomes including cardiorespiratory fitness (CRF). Purpose Our aim was to examine changes in CRF and C-reactive protein (CRP), a surrogate for IL-1 activity, in patients with HFpEF treated with the IL-1 recombinant human receptor antagonist anakinra, stratified according to resting LVEF. Methods We analyzed data from 32 patients (median age 55 [51-64] years, 24 (75%) female) with HFpEF, defined as a presence of HF symptoms, LVEF≥50%, and evidence of left ventricular diastolic dysfunction or elevated filling pressures. All patients were treated with anakinra 100 mg subcutaneously daily for 12 [2-12] weeks. Patients were stratified into two groups: LVEF 50-59% and LVEF ≥60%. At baseline and during treatment, patients underwent cardiopulmonary exercise testing and venipuncture to measure changes in peak oxygen consumption (peak VO2) and CRP. Categorical and continuous variables are expressed as N (%) and median (interquartile range) and were compared with the chi-square and Mann-Whitney test, respectively. The within-group paired differences were compared using the Wilcoxon signed-rank test. Results The cohort included 15 patients with LVEF 50-59% and 17 with LVEF ≥60%, without significant differences in age and sex between groups. In patients with LVEF 50-59% and ≥60%, baseline peak VO2 was 14.1 [13.1–17.3] and 13.8 [11.8-18.6] mLO2·kg-1·min-1, respectively (p = 0.82), and CRP was 6.2 [3.4-15.9] and 6.1 [3.7-17.6] mg/L, respectively (p = 0.74). A significant increase in peak VO2 (from 13.8 [11.8-18.6] to 15.8 [12.7-19.9] mLO2·kg-1·min-1, p = 0.033) and decrease in CRP (from 6.2 [3.4-15.9] mg/L to 3.4 [1.0-6.7] mg/L, p = 0.003) was seen in patients with LVEF ≥60%; whereas in those with LVEF 50-59% there were no significant changes in peak VO2 (from 14.1 [13.1–17.3] to 14.1 [11.0–17.3] mLO2·kg-1·min-1, p = 0.25) despite a significant reduction in CRP (from 6.1 [3.7-17.6] mg/L to 1.4 [0.8-11.4] mg/L, p = 0.016). We found a difference in the interval changes in peak VO2 (0 [from -1.1 to +0.3] vs +1.7 [from -0.7 to +2.3] mLO2·kg-1·min-1 in patients with LVEF 50-59% and ≥60%, respectively, p = 0.01), without differences in the interval change in CRP levels (–3.5 [from -6 to -2.1] vs –3.0 [from -11.4 to -2.1] mg/L, respectively, p = 0.91). Figure 1. Conclusions Patients with HFpEF demonstrate differential peak VO2 response to anakinra treatment based on resting LVEF, with those with a LVEF ≥60% showing greater improvement in CRF. Further randomized control trials are needed to validate these data and explore the potential underlying mechanisms.

Longitudinal changes in cardiorespiratory fitness among firefighters based on a fixed 12.0 MET standard and an age-adjusted fitness standard.

Firefighting is a physically demanding profession. Firefighters (FFs) need adequate physical fitness (PF) to perform duty tasks efficiently. While FFs' work demands are constant throughout their career, there is an expected age-related decline in PF. To describe longitudinal changes in cardiorespiratory fitness (CRF) based on a fixed (12.0 METs) and an age-adjusted standard and compare the prevalence of fit/unfit firefighters (FFs) over eight years. 297 Brazilian male firefighters were randomly selected. CRF was assessed by the 12-minute Cooper test. To compare the prevalence's of fit/unfit FFs depending on the standard (12 METs vs. age-adjusted), the McNemar test was used. The reduction in the prevalence of fit firefighters was 4.4-fold higher when the analysis did not consider age. After eight years, the prevalence of fit FFs decreased by 30.5% based on the fixed standard, while this reduction was only 7% when using an age-adjusted standard.