These findings support a reappraisal of current clinical interpretation of cardiorespiratory fitness highlighting the potential for incorrect fitness stratification when natural variation is not accounted for.

New Findings What is the central question of this study?To what extent cardiorespiratory fitness is impaired in patients with abdominal aortic aneurysmal (AAA) disease and corresponding implications for postoperative survival requires further investigation. What is the main finding and its importance?Cardiorespiratory fitness is impaired in patients with AAA disease. Patients with peak oxygen uptake of <13.1 ml O2 kg−1 min−1 and ventilatory equivalent for carbon dioxide at anaerobic threshold ≥34 are associated with increased risk of postoperative mortality at 2 years. These findings demonstrate that cardiorespiratory fitness can predict mid‐term postoperative survival in AAA patients, which may help to direct care provision. Abstract Preoperative cardiopulmonary exercise testing is a standard assessment of cardiorespiratory fitness (CRF) and risk stratification. However, to what extent CRF is impaired in patients undergoing surgical repair of abdominal aortic aneurysm (AAA) disease and the corresponding implications for postoperative outcome requires further investigation. We measured CRF during an incremental exercise test to exhaustion using online respiratory gas analysis in patients with AAA disease (n = 124, aged 72 ± 7 years) and healthy sedentary control subjects (n = 104, aged 70 ± 7 years). Postoperative survival was examined for association with CRF, and threshold values were calculated for independent predictors of mortality. Patients who underwent preoperative cardiopulmonary exercise testing before surgical repair had lower CRF [age‐adjusted mean difference of 12.5 ml O2 kg−1 min−1 for peak oxygen uptake (V̇O2 peak ), P < 0.001 versus control subjects]. After multivariable analysis, both V̇O2 peak and the ventilatory equivalent for carbon dioxide at anaerobic threshold (V̇E/V̇normalCO2− AT ) were independent predictors of mid‐term postoperative survival (2 years). Hazard ratios of 5.27 (95% confidence interval 1.62–17.14, P = 0.006) and 3.26 (95% confidence interval 1.00–10.59, P = 0.049) were observed for V̇O2 peak  < 13.1 ml O2 kg−1 min−1 and V̇E/V̇normalCO2− AT ≥ 34, respectively. Thus, CRF is lower in patients with AAA, and those with a V̇O2 peak  < 13.1 ml O2 kg−1 min−1 and V̇E/V̇normalCO2− AT ≥ 34 are associated with a markedly increased risk of postoperative mortality. Collectively, our findings demonstrate that CRF can predict mid‐term postoperative survival in AAA patients, which may help to direct care provision.

Contact events in rugby union remain a public health concern. We determined the molecular, cerebrovascular and cognitive consequences of contact events during a season of professional rugby. Twenty-one male players aged 25 (mean) ± 4 (SD) years were recruited from a professional rugby team comprising forwards (n = 13) and backs (n = 8). Data were collected across the season. Pre-and post-season, venous blood was assayed for the ascorbate free radical (A •-, electron paramagnetic resonance spectroscopy) and nitric oxide (NO, reductive ozone-based chemiluminescence) to quantify oxidative-nitrosative stress (OXNOS). Middle cerebral artery velocity (MCAv, Doppler ultrasound) was measured to assess cerebrovascular reactivity (CVR), and cognition was assessed using the Montreal Cognitive Assessment (MoCA). Notational analysis determined contact events over the season. Forwards incurred more collisions (Mean difference [M D ] 7.49; 95% CI, 2.58-12.40; P = 0.005), tackles (M D 3.49; 95% CI, 0.42-6.56; P = 0.028) and jackals (M D 2.21; 95% CI, 0.18-4.24; P = 0.034). Forwards suffered five concussions while backs suffered one concussion. An increase in systemic OXNOS, confirmed by elevated A •-(F 2,19 = 10.589, P = 0.004) and corresponding suppression of NO bioavailability (F 2,19 = 11.492, P = 0.003) was apparent in forwards and backs across the season. This was accompanied by a reduction in cerebral oxygen delivery (cD O 2 , F 2,19 = 9.440, P = 0.006) and cognition (F 2,19 = 4.813, P = 0.041).Forwards exhibited a greater decline in the cerebrovascular reactivity range to changes in PET CO2 (CVR CO 2 RANG compared to backs (M D 1.378; 95% CI, 0.74-2.02; P < 0.001).

Physiolometrics and the puzzle of methodical acumen'It is of the highest importance in the art of detection to be able to recognize, out of a number of facts, which are incidental and which vital!' These words, spoken by Sherlock Holmes in The Adventure of the Reigate Squire (later also known as The Adventure of the Reigate Puzzle) published in the June issue of The Strand Magazine in 1893, resonate with our quest as physiologists for methodological rigor to this day.

Surgery accounts for 7.7% of all deaths globally and the number of procedures is increasing annually. A patient's 'fitness for surgery' describes the ability to tolerate a physiological insult, fundamental to risk assessment and care planning. We have evolved as obligate aerobes that rely on oxygen (O 2 ). Systemic O 2 consumption can be measured via cardiopulmonary exercise testing (CPET) providing objective metrics of cardiorespiratory fitness (CRF). Impaired CRF is an independent risk factor for mortality and morbidity. The perioperative period is associated with increased O 2 demand, which if not met leads to O 2 deficit, the magnitude and duration of which dictates organ failure and ultimately death. CRF is by far the greatest modifiable risk factor, and optimal exercise interventions are currently under investigation in patient prehabilitation programmes. However, current practice demonstrates potential for up to 60% of patients, who undergo preoperative CPET, to have their fitness incorrectly stratified. To optimise this work we must improve the detection of CRF and reduce potential for interpretive error that may misinform risk classification and subsequent patient care, better quantify risk by expressing the power of CRF to predict mortality and morbidity compared to traditional cardiovascular risk factors, and improve patient interventions with the capacity to further enhance vascular adaptation. Thus, a better understanding of CRF, used to determine fitness for surgery, will enable both clinicians and exercise physiologists to further refine patient care and management to improve survival.