Exercise intensity measurement using fractal analysis of heart rate variability: Reliability, agreement and influence of sex and cardiorespiratory fitness

The study aimed to establish the test-retest reliability of detrended fluctuation analysis of heart rate variability (DFA-α1) based exercise intensity thresholds, assess its agreement with ventilatory- and lactate-derived thresholds and the moderating effect of sex and cardiorespiratory fitness (CRF) on the agreement. Intensity thresholds for thirty-seven participants (17 females) based on blood lactate (LT 1/LT 2), gas-exchange (VT 1/VT 2) and DFA-α1 (αTh 1/αTh 2) were assessed. Heart rate (HR) at αTh 1 and αTh 2 showed good test-retest reliability (coefficient of variation [CV] &lt; 6%), and moderate to high agreement with LTs ( r  = 0.40 - 0.57) and VTs ( r  = 0.61 - 0.66) respectively. Mixed effects models indicated bias magnitude depended on CRF, with DFA-α1 overestimating thresholds versus VTs for lower fitness levels (speed at VT 1 &lt;8.5 km⋅hr -1), while underestimating for higher fitness levels (speed at VT 2 &gt;15 km⋅hr -1; VO 2max &gt;55 mL·kg -1·min -1). Controlling for CRF, sex significantly affected bias magnitude only at first threshold, with males having higher mean bias (+2.41 bpm) than females (-1.26 bpm). DFA-α1 thresholds are practical and reliable intensity measures, however it is unclear if they accurately represent LTs/VTs from the observed limits of agreement and unexplained variance. To optimise DFA-α1 threshold estimation across different populations, bias should be corrected based on sex and CRF. </p

Rheumatoid Cachexia: causes, significance and possible interventions

Rheumatoid arthritis is a chronic autoimmune disease characterised by joint pain and stiffness but also systemic mutli-organ involvement. Several features are due to excessive production of inflammatory cytokines, particularly tumour necrosis factor alpha, interleukin-1 and interleukin-6. These are implicated in both local synovial inflammation, which causes joint destruction, but also systemic inflammation, which can cause loss of body cell mass, amongst other phenomena. Body cell mass breakdown in rheumatoid arthritis leads to the classical, but largely ignored, metabolic abnormality known as rheumatoid cachexia. Cachexia is a very strong predictor of adverse functional outcome and death in many disease states. In this review we highlight the mechanisms linked with rheumatoid cachexia and discuss possible interventions that may limit this in patients with rheumatoid arthritis

Daily energy expenditure and water turnover in female netball players from the Netball Super League : a doubly labeled water observation study

DATA AVAILABILITY STATEMENT : All data generated or analyzed during this study are included in this published article. Any further information is available upon request.Please read abstract in the article.Leeds Beckett University.https://onlinelibrary.wiley.com/journal/15367290hj2024Sports MedicineSDG-03:Good heatlh and well-bein

Vascular Structure and Functional Responses to Consecutive High-Fat Feeding between Insulin Treatment Regimens in Adults with Type 1 Diabetes and Matched Controls [Poster]

Background: Impaired vascular health is prevalent in type 1 diabetes (T1D); however, it remains unknown whether different insulin treatment regimens mediate indices of vascular structure or function. Methods: Sixteen individuals with T1D receiving either multiple daily injection therapy (MDI; n=8; age: 32±13years; BMI:26.0±5.9kg.m2; HbA1c:53.7±11.2mmol/mol [7.1±3.2%]) or continuous subcutaneous insulin infusion (CSII; n=8; age:35±18years; BMI:26.3±4.6kg.m2; HbA1c: 58.6±9.7mmol/mol [7.5±3.0%]) and ten matched controls (CON; age:31±13years; BMI: 24.3±2.9kg.m2) consumed two high fat (HF) meals at 4-hour intervals. Carotid artery intima-media thickness (CIMT) and flow mediated dilation (FMD) was assessed at baseline, with further FMD assessment at 3-hours following the ingestion of each meal using high resolution B-mode ultrasound. Bolus insulin dose was standardized using the carbohydrate-counting method. Results: CIMT was significantly higher in individuals with T1D compared to controls (p=0.039); treatment stratification within T1D revealed MDI mediated this effect (MDI vs. CON: p=0.049; CSII vs. CON: p=0.112). FMD remained unchanged following the first meal (p=0.204) but was significantly impaired following the second meal (p=<0.001); post hoc analysis revealed MDI mediated this effect of impaired FMD after the second meal (MDI vs. CON: p=0.048; CSII vs. CON: p=0.416). Conclusions: Our findings indicate that patients treated with MDI therapy have higher CIMT (a structural marker of subclinical atherosclerosis) compared to controls but not CSII therapy. FMD was impaired following a second HF meal irrespective of a diabetes status. Considering the pre-existing heightened cardiovascular disease risk in T1D therapeutic strategies to reduce postprandial risk warrants further research

Cardiorespiratory fitness levels and their association with cardiovascular profile in patients with rheumatoid arthritis:a cross-sectional study

Objective. The aim of this study was to investigate the association of different physical fitness levels [assessed by the maximal oxygen uptake (VO2max) test] with cardiovascular disease (CVD) risk factors in patients with RA. Methods. A total of 150 RA patients were assessed for cardiorespiratory fitness with a VO2max test and, based on this, were split in three groups using the 33rd (18.1 ml/kg/min) and 66th (22.4 ml/kg/min) centiles. Classical and novel CVD risk factors [blood pressure, body fat, insulin resistance, cholesterol, triglycerides, high-density lipoprotein (HDL), physical activity, CRP, fibrinogen and white cell count], 10-year CVD risk, disease activity (DAS28) and severity (HAQ) were assessed in all cases. Results. Mean VO2max for all RA patients was 20.9 (s.d. 5.7) ml/kg/min. The 10-year CVD risk (P = 0.003), systolic blood pressure (P = 0.039), HDL (P = 0.017), insulin resistance and body fat (both at P &lt; 0.001), CRP (P = 0.005), white blood cell count (P = 0.015) and fibrinogen (P &lt; 0.001) were significantly different between the VO2max tertiles favouring the group with the higher VO2max levels. In multivariate analyses of variance, VO2max was significantly associated with body fat (P &lt; 0.001), HDL (P = 0.007), insulin resistance (P &lt; 0.003) and 10-year CVD risk (P &lt; 0.001), even after adjustment for DAS28, HAQ and physical activity. Conclusion. VO2max levels are alarmingly low in RA patients. Higher levels of VO2max are associated with a better cardiovascular profile in this population. Future studies need to focus on developing effective behavioural interventions to improve cardiorespiratory fitness in RA

The role of exercise in the management of rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic inflammatory disease associated with significant functional impairment and increased risk for cardiovascular disease. Along with pharmacological therapy, exercise seems to be a very promising intervention to improve disease-related outcomes, including functional ability and systemic manifestations, such as the increased cardiovascular risk. In this review, we discuss the physiological mechanisms by which exercise improves inflammation, cardiovascular risk and psychological health in patients with rheumatoid arthritis (RA) and describe in detail how exercise can be incorporated in the management of this disease using real examples from our clinical practice. © 2015 Informa UK, Ltd