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Individuals with cervical spinal cord injury (SCI) are at an increased risk for cardiovascular disease. Exercise is well-established for preventing cardiovascular disease; however, there are limited straightforward and safe exercise approaches for increasing the activity of the cardiorespiratory system after cervical SCI. The objective of this study was to investigate the cardiorespiratory response to passive leg cycling in people with cervical SCI. Beat-by-beat blood pressure, heart rate, and cerebral blood flow were measured before and throughout 10 minutes of cycling in 11 people with SCI. Femoral artery flow-mediated dilation was also assessed before and immediately after passive cycling. Safety was monitored throughout all study visits. Passive cycling elevated systolic blood pressure (5 ± 2 mm Hg), mean arterial pressure (5 ± 3 mm Hg), stroke volume (2.4 ± 0.8 mL), heart rate (2 ± 1 beats/min) and cardiac output (0.3 ± 0.07 L/min; all p  < 0.05). Minute ventilation (0.67 ± 0.23 L/min), tidal volume (70 ± 30 mL) and end-tidal PO 2 (2.6 ± 1.23 mm Hg) also increased (all p  < 0.05). Endothelial function was improved immediately after exercise (1.62 ± 0.13%, p  < 0.01). Passive cycling resulted in an incidence of autonomic dysreflexia. Therefore, passive leg cycling increased the activity of the cardiorespiratory system and improved endothelial function, indicating it may be a beneficial exercise intervention for the cardiovascular and respiratory systems in people with cervical SCI. Novelty: Passive leg cycling increases the activity of the cardiorespiratory system and improves markers of cardiovascular health in cervical SCI. Passive leg cycling exercise is an effective, low-cost, practical, alternative exercise modality for people with cervical SCI.

We sought to determine the impact of wearing cloth or surgical masks on the cardiopulmonary responses to moderate-intensity exercise. Twelve subjects ( n  = 5 females) completed three, 8-min cycling trials while breathing through a non-rebreathing valve (laboratory control), cloth, or surgical mask. Heart rate (HR), oxyhemoglobin saturation (SpO 2 ), breathing frequency, mouth pressure, partial pressure of end-tidal carbon dioxide (P et CO 2 ) and oxygen (P et O 2 ), dyspnea were measured throughout exercise. A subset of n  = 6 subjects completed an additional exercise bout without a mask (ecological control). There were no differences in breathing frequency, HR or SpO 2 across conditions (all p  > 0.05). Compared with the laboratory control (4.7 ± 0.9 cmH 2 O [mean ± SD]), mouth pressure swings were smaller with the surgical mask (0.9 ± 0.7; p  < 0.0001), but similar with the cloth mask (3.6 ± 4.8 cmH 2 O; p  = 0.66). Wearing a cloth mask decreased P et O 2 (-3.5 ± 3.7 mm Hg) and increased P et CO 2 (+2.0 ± 1.3 mm Hg) relative to the ecological control (both p  < 0.05). There were no differences in end-tidal gases between mask conditions and laboratory control (both p  > 0.05). Dyspnea was similar between the control conditions and the surgical mask ( p  > 0.05) but was greater with the cloth mask compared with laboratory (+0.9 ± 1.2) and ecological (+1.5 ± 1.3) control conditions (both p  < 0.05). Wearing a mask during short-term moderate-intensity exercise may increase dyspnea but has minimal impact on the cardiopulmonary response. Novelty: Wearing surgical or cloth masks during exercise has no impact on breathing frequency, tidal volume, oxygenation, and heart rate However, there are some changes in inspired and expired gas fractions that are physiologically irrelevant. In young healthy individuals, wearing surgical or cloth masks during submaximal exercise has few physiological consequences.

Rock climbing has become a mainstream sport, contested on the Olympic stage. The work/rest pattern of bouldering is unique among disciplines, and little is known about its physiological demands. This study characterised the cardiorespiratory responses to simulated competition. Eleven elite boulderers (7 male) volunteered to participate (age = 23.3 ± 4.5 years; mass = 68.2 ± 9.7 kg; stature = 1.73 ± 0.06 m; body fat = 10.4% ± 5%). Subjects completed incremental treadmill running to determine maximal capacities. On a separate day, they undertook a simulated Olympic-style climbing competition comprising 5 boulder problems, each separated by 5 min of rest. Pulmonary ventilation, gas exchange, and heart rate were assessed throughout. Total climbing time was 18.9 ± 2.7 min. Bouldering elicited a peak oxygen uptake of 35.8 ± 7.3 mL·kg -1 ·min -1 (∼75% of treadmill maximum) and a peak heart rate of 162 ± 14 beats·min -1 (∼88% of maximum). Subjects spent 22.9% ± 8.6% of climbing time above the gas exchange threshold. At exercise cessation, there was an abrupt and significant increase in tidal volume (1.4 ± 0.4 vs. 1.8 ± 0.4 L; p = 0.006, d = 0.83) despite unchanged minute ventilation. Cardiorespiratory parameters returned to baseline within 4 min of the rest period. In conclusion, competitive bouldering elicits substantial cardiorespiratory demand and evidence of tidal volume constraint. Further studies are warranted to explore the effect of cardiorespiratory training on climbing performance. Novelty: Competitive bouldering evokes a high fraction of maximal oxygen uptake and prolonged periods above the gas exchange threshold. Climbing appears to impose a constraint on tidal volume expansion. Cardiorespiratory indices in elite climbers return to baseline within 2-4 min.