AUTHOR=Nicolò Andrea , Girardi Michele , Bazzucchi Ilenia , Sacchetti Massimo , Felici Francesco 

TITLE=Ventilation and perceived exertion are sensitive to changes in exercise tolerance: arm+leg cycling vs. leg cycling

JOURNAL=Frontiers in Physiology

VOLUME=14

YEAR=2023

URL=https://www.frontiersin.org/journals/physiology/articles/10.3389/fphys.2023.1226421

DOI=10.3389/fphys.2023.1226421

ISSN=1664-042X

ABSTRACT=<p><bold>Purpose:</bold> Growing evidence suggests that respiratory frequency (<italic>f</italic><sub>R</sub>) is a marker of physical effort and a variable sensitive to changes in exercise tolerance. The comparison between arm+leg cycling (Arm+leg) and leg cycling (Leg) has the potential to further test this notion because a greater exercise tolerance is expected in the Arm+leg modality. We systematically compared Arm+leg vs. Leg using different performance tests.</p><p><bold>Methods:</bold> Twelve males underwent six performance tests in separate, randomized visits. Three tests were performed in each of the two exercise modalities, i.e. an incremental test and two time-to-exhaustion (TTE) tests performed at 90% or 75% of the peak power output reached in the Leg incremental test (PPO<sub>Leg</sub>). Exercise tolerance, perceived exertion, and cardiorespiratory variables were recorded during all the tests.</p><p><bold>Results:</bold> A greater exercise tolerance (<italic>p</italic> &lt; 0.001) was found for Arm+leg in the incremental test (337 ± 32 W vs. 292 ± 28 W), in the TTE test at 90% of PPO<sub>Leg</sub> (638 ± 154 s vs. 307 ± 67 s), and in the TTE test at 75% of PPO<sub>Leg</sub> (1,675 ± 525 s vs. 880 ± 363 s). Unlike <inline-formula id="inf1"><mml:math id="m1" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mover accent="true"><mml:mi mathvariant="normal">V</mml:mi><mml:mo>˙</mml:mo></mml:mover></mml:mrow></mml:math></inline-formula>O<sub>2</sub> and heart rate, both <italic>f</italic><sub>R</sub> and minute ventilation were lower (<italic>p</italic> &lt; 0.003) at isotime in all the Arm+leg tests vs. Leg tests. Furthermore, a lower perceived exertion was observed in the Arm+leg tests, especially during the TTE tests (<italic>p</italic> &lt; 0.001).</p><p><bold>Conclusion:</bold> Minute ventilation, <italic>f</italic><sub>R</sub> and perceived exertion are sensitive to the improvements in exercise tolerance observed when comparing Arm+leg vs. Leg, unlike <inline-formula id="inf2"><mml:math id="m2" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mover accent="true"><mml:mi mathvariant="normal">V</mml:mi><mml:mo>˙</mml:mo></mml:mover></mml:mrow></mml:math></inline-formula>O<sub>2</sub> and heart rate.</p>