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Knowledge of muscle contractile properties, physical fitness, and their associations with perceived fatigue may provide insights into mechanisms inducing fatigue and treatment targets. We aimed to identify differences in contractile properties and physical fitness between populations, and examine associations with perceived fatigue. We pooled data on perceived fatigue, physical fitness, and contractile properties from six studies, including a control group (n = 90), cancer survivors (n = 27), patients with chronic obstructive pulmonary disease (COPD; n = 16), chronic myeloid leukemia (CML; n = 20), and statin users (n = 64). We evaluated differences between populations, and associations of contractile properties and physical fitness with perceived fatigue. Compared with the control group, we found differences in contractile properties of patients with COPD (larger muscle force decline: β = −10.5%, 95% CI = −16.7; −4.2, increase in early relaxation time (Rt): β = 84.4%, 95% CI = 51.7; 117.0, increase in half Rt: β = 83.1%, 95% CI = 45.5; 120.7, muscle force rise (MFR): β = 0.2%/ms, 95% CI = 0.1; 0.3, and decrease in MFR: β = −24.3%, 95% CI = −35.7; −13.0) and statin users (early Rt: β = −5.4 ms, 95% CI = −10.0; −0.8, increase in early Rt: β = 19.8%, 95% CI = 2.5; 37.1). Associations between contractile properties and perceived fatigue varied across populations. Longer relaxation times were associated with higher perceived fatigue in hemato‐oncological populations. To conclude, contractile properties were impaired in patients with COPD and statin users. Associations between contractile properties and perceived fatigue varied across populations. In hemato‐oncological populations, impaired muscle relaxation was associated with higher perceived fatigue. [ABSTRACT FROM AUTHOR]

Background Moderate to vigorous physical activity (MVPA) is strongly associated with risk reductions of noncommunicable diseases and mortality. Cardiovascular health status may influence the benefits of MVPA. We compare the association between MVPA and incident major adverse cardiovascular events (MACE) and mortality between healthy individuals, individuals with elevated levels of cardiovascular risk factors (CVRF), and cardiovascular disease (CVD). Methods and findings A cohort study was performed in the 3 northern provinces of the Netherlands, in which data were collected between 2006 and 2018, with a median follow-up of 6.8 years (Q.sub.25 5.7; Q.sub.75 7.9). A total of 142,493 participants of the Lifelines Cohort Study were stratified at baseline as (1) healthy; (2) CVRF; or (3) CVD. Individuals were categorized into 'inactive' and 4 quartiles of least (Q1) to most (Q4) active based on self-reported MVPA volumes. Primary outcome was a composite of incident MACE and all-cause mortality during follow-up. Cox regression was used to estimate hazard ratios (HRs), 95% confidence intervals (CIs) and P values. The main analyses were stratified on baseline health status and adjusted for age, sex, income, education, alcohol consumption, smoking, protein, fat and carbohydrate intake, kidney function, arrhythmias, hypothyroid, lung disease, osteoarthritis, and rheumatoid arthritis. The event rates were 2.2% in healthy individuals (n = 2,485 of n = 112,018), 7.9% in those with CVRF (n = 2,214 of n = 27,982) and 40.9% in those with CVD (n = 1,019 of n = 2,493). No linear association between MVPA and all-cause mortality or MACE was found for healthy individuals (P = 0.36) and individuals with CVRF (P = 0.86), but a linear association was demonstrated for individuals with CVD (P = 0.04). Adjusted HRs in healthy individuals were 0.81 (95% CI 0.64 to 1.02, P = 0.07), 0.71 (95% CI 0.56 to 0.89, P = 0.004), 0.72 (95% CI 0.57 to 0.91, P = 0.006), and 0.76 (95% CI 0.60 to 0.96, P = 0.02) for MVPA Q1 to Q4, respectively, compared to inactive individuals. In individuals with CVRF, HRs were 0.69 (95% CI 0.57 to 0.82, P < 0.001), 0.66 (95% CI 0.55 to 0.80, P < 0.001), 0.64 (95% CI 0.53 to 0.77, P < 0.001), and 0.69 (95% CI 0.57 to 0.84, P < 0.001) for MVPA Q1 to Q4, respectively, compared to inactive individuals. Finally, HRs for MVPA Q1 to Q4 compared to inactive individuals were 0.80 (95% CI 0.62 to 1.03, P = 0.09), 0.82 (95% CI 0.63 to 1.06, P = 0.13), 0.74 (95% CI 0.57 to 0.95, P = 0.02), and 0.70 (95% CI 0.53 to 0.93, P = 0.01) in CVD patients. Leisure MVPA was associated with the most health benefits, nonleisure MVPA with little health benefits, and occupational MVPA with no health benefits. Study limitations include its observational nature, self-report data about MVPA, and potentially residual confounding despite extensive adjustment for lifestyle risk factors and health-related factors. Conclusions MVPA is beneficial for reducing adverse outcomes, but the shape of the association depends on cardiovascular health status. A curvilinear association was found in healthy and CVRF individuals with a steep risk reduction at low to moderate MVPA volumes and benefits plateauing at high(er) MVPA volumes. CVD patients demonstrated a linear association, suggesting a constant reduction of risk with higher volumes of MVPA. Therefore, individuals with CVDs should be encouraged that 'more is better' regarding MVPA. These findings may help to optimize exercise prescription to gain maximal benefits of a physically active lifestyle., Author(s): Esmée A. Bakker 1,2, Duck-chul Lee 3, Maria T. E. Hopman 1, Eline J. Oymans 1, Paula M. Watson 2, Paul D. Thompson 4, Dick H. J. Thijssen 1,2, [...]

The magnitude of exercise-induced cardiac troponin (cTn) elevations is dependent on cardiovascular health status, and previous studies have shown that occult coronary atherosclerosis is highly prevalent among amateur athletes. We tested the hypothesis that middle-aged and older athletes with coronary atherosclerosis demonstrate greater cTn elevations following a controlled endurance exercise test compared with healthy peers. We included 59 male athletes from the Measuring Athletes' Risk of Cardiovascular events 2 (MARC-2) study and stratified them as controls [coronary artery calcium score (CACS) = 0, n = 20], high CACS [≥300 Agatston units or ≥75th Multi-Ethnic Study of Atherosclerosis (MESA) percentile, n = 20] or significant stenosis (≥50% in any coronary artery, n = 19). Participants performed a cycling test with incremental workload until volitional exhaustion. Serial high-sensitivity cTn (hs-cTn) T and I concentrations were measured (baseline, after 30-min warm-up, and 0, 30, 60, 120, and 180 min postexercise). There were 58 participants (61 [58–69] yr) who completed the exercise test (76 ± 14 min) with a peak heart rate of 97.7 [94.8–101.8]% of their estimated maximum. Exercise duration and workload did not differ across groups. High-sensitivity cardiac troponin T (Hs-cTnT) and high-sensitivity cardiac troponin I (hs-cTnI) concentrations significantly increased (1.55 [1.33–2.14]-fold and 2.76 [1.89–3.86]-fold, respectively) over time, but patterns of cTn changes and the incidence of concentrations >99th percentile did not differ across groups. Serial sampling of hs-cTnT and hs-cTnI concentrations during and following an exhaustive endurance exercise test did not reveal differences in exercise-induced cTn release between athletes with versus without coronary atherosclerosis. These findings suggest that a high CACS or a >50% stenosis in any coronary artery does not aggravate exercise-induced cTn release in middle-aged and older athletes. NEW & NOTEWORTHY: Exercise-induced cardiac troponin (cTn) release is considered to be dependent on cardiovascular health status. We tested whether athletes with coronary atherosclerosis demonstrate greater exercise-induced cTn release compared with healthy peers. Athletes with coronary atherosclerosis did not differ in cTn release following exercise compared with healthy peers. Our findings suggest that a high CACS or a >50% stenosis in any coronary artery does not aggravate exercise-induced cTn release in middle-aged and older athletes. [ABSTRACT FROM AUTHOR]

Increased consumption of dietary nitrate increases plasma nitrate and nitrite concentrations, and has been shown to elicit cardio-protective effects and improve exercise performance. Nitrate consumption in the habitual diet is mainly dependent on nitrate-rich vegetables, such as green leafy and root vegetables, with total vegetable consumption accounting for approximately 50-85% of our daily nitrate intake. Whereas 'supplementation' with dietary nitrate in research studies has mainly been accomplished through the use of (concentrated) nitrate-rich beetroot juice, dietary strategies focusing on increased intake of nitrate-rich vegetables may represent a similarly effective alternative for increasing dietary nitrate intake and, as such, obtaining the associated cardiovascular health and ergogenic benefits., Author(s): Cindy M. T. Van der Avoort [sup.1] [sup.2] [sup.3] , Luc J. C. Van Loon [sup.1] [sup.2] , Maria T. E. Hopman [sup.3] , Lex B. Verdijk [sup.1] Author [...]