## Appendix A  
_Cardiopulmonary Tests_  
Groups underwent different cardiopulmonary-tensity (CPET), which are summarized below:  
Group A (Athletes): In the morning, under temperate conditions (21-22 \({}^{\circ}\)C, 50-60% humidity), rowers with varied training undergo a cycling exercise test. Following a standard breakfast and clinical assessments, they start cycling at 60-70 rpm. The test begins with a minute of rest, then a minute at 0 W, escalating the workload by 20 W/min for one group and 15 W/min for the others. Their exertion, respiratory exchange, heart rate, and gas exchange are closely monitored using the Quark RMR-CPET Cosmed(tm) (Rome, Italy) and a Garmin(r) (Olathe, KS, USA) heart rate monitor, ensuring a detailed evaluation of their physical response [6].  
Group O (Obese): During similar morning conditions, obese participants engage in a treadmill exercise following their usual breakfast and anthropometric measurements. The exercise begins at a leisurely 3 km/h, gradually increasing in speed and slope. Their cardiovascular and respiratory responses are meticulously recorded, utilizing a Woodway PRO (Woodway, Waukesha, WI, USA) treadmill and Quark RMR-CPET Cosmed(tm) equipment [7].  
Group C (Cardiac patients): These individuals underwent their exercise regimen in the morning. Using a cycle-ergometer, the exercise starts at a low intensity of 20 watts, increasing by 10 watts every minute until the participant reaches exhaustion, indicated by a plateau in oxygen uptake. This protocol is especially cautious, considering their heart condition, and includes comprehensive monitoring of heart rate and gas exchange using specialized equipment such as the ERG 900 and GE Medical System's CASE Exercise Testing System (GE Healthcare Technologies, Inc., Chicago, IL, USA) [31; 32].  
Group Y (Young Athletes): Conducted either late in the morning or late afternoon, young athletes undergo their tests in controlled conditions (20-22 \({}^{\circ}\)C, 40-50% humidity, 1015 mb above sea level). After ensuring no physical activity or stimulant intake prior to the test, they engage in a cycling exercise that starts with a resting phase, followed by unloaded pedaling, and then an incremental increase of 15 watts per minute until exhaustion. Their physical responses, including heart rate and respiratory parameters, are closely monitored using advanced equipment like the LODE-Cervical cycle-ergometer (Groningen, The Netherlands) and COSMED K5 Portable Metabolic Analysis Technology System (Rome, Italy), providing vital data on their endurance and physical capabilities [17].  
During each test, the perception of physical exertion was assessed using the OMNI Scale of Perceived Exertion (ranging from 0 to 10) [4], measured 15 s prior to the end of each stage. Participants were asked to rate their subjective intensity of effort on a scale from 0 (extremely easy) to 10 (extremely hard). The test was terminated when any of the following conditions were met: a rating of 10 on the OMNI Scale, 90% of the subject's predicted Maximum Heart Rate (HRmax, calculated using the well-known Fox formula HRmax = 220-age, beats/min [18]), or a respiratory exchange ratio (the ratio between thevolume of CO2 being produced by the body and the amount of O2 being consumed) equal to 1.1.