OBJECTIVES: Ventilation ( [Formula: see text] ) as a function of CO2 output, and oxygen uptake ( [Formula: see text] ) as a function of [Formula: see text] , define cardio-respiratory efficiency, although few data compare efficiency with maximum oxygen uptake ( [Formula: see text] ), or consider reproducibility. Currently there are no data for trained juveniles. DESIGN: Twenty-five trained juvenile cyclists (mean age 14.7 years), performed maximal exercise testing on two occasions, separated by 16 weeks. METHODS: [Formula: see text] vs. [Formula: see text] slope, oxygen uptake efficiency slope, and [Formula: see text] were measured during cycle ergometer exercise to volitional exhaustion on two occasions, 16 weeks apart. RESULTS: Mean (SD) [Formula: see text] vs. [Formula: see text] slope, oxygen uptake efficiency slope, and [Formula: see text] were 28.14 (3.89), 4.16 (0.73), and 75.4 (8.9) mlkg(-1)min(-1) on visit 1, and 27.92 (4.63), 4.22 (0.76), and 73.6 (9.3) mlkg(-1)min(-1) on visit 2. Good reproducibility (differences ≤2.4%), but poor correlations (r≤0.29) between efficiency and [Formula: see text] were recorded. CONCLUSIONS: Reproducibility of efficiency measures was comparable to [Formula: see text] , however, poor associations between efficiency and [Formula: see text] suggested independence. Efficient ventilation may be of limited importance in determining the [Formula: see text] in a trained juvenile cyclist.
OBJECTIVES: Ventilation ( [Formula: see text] ) as a function of CO2 output, and oxygen uptake ( [Formula: see text] ) as a function of [Formula: see text] , define cardio-respiratory efficiency, although few data compare efficiency with maximum oxygen uptake ( [Formula: see text] ), or consider reproducibility. Currently there are no data for trained juveniles. DESIGN: Twenty-five trained juvenile cyclists (mean age 14.7 years), performed maximal exercise testing on two occasions, separated by 16 weeks. METHODS: [Formula: see text] vs. [Formula: see text] slope, oxygen uptake efficiency slope, and [Formula: see text] were measured during cycle ergometer exercise to volitional exhaustion on two occasions, 16 weeks apart. RESULTS: Mean (SD) [Formula: see text] vs. [Formula: see text] slope, oxygen uptake efficiency slope, and [Formula: see text] were 28.14 (3.89), 4.16 (0.73), and 75.4 (8.9) mlkg(-1)min(-1) on visit 1, and 27.92 (4.63), 4.22 (0.76), and 73.6 (9.3) mlkg(-1)min(-1) on visit 2. Good reproducibility (differences ≤2.4%), but poor correlations (r≤0.29) between efficiency and [Formula: see text] were recorded. CONCLUSIONS: Reproducibility of efficiency measures was comparable to [Formula: see text] , however, poor associations between efficiency and [Formula: see text] suggested independence. Efficient ventilation may be of limited importance in determining the [Formula: see text] in a trained juvenile cyclist.
Authors: Eduardo Salazar-Martínez; Hannes Gatterer; Martin Burtscher; José Naranjo Orellana; Alfredo Santalla Journal: Front Physiol Date: 2017-03-08 Impact factor: 4.566
Authors: Lluis Albesa-Albiol; Noemí Serra-Payá; María Ana Garnacho-Castaño; Lluis Guirao Cano; Eulogio Pleguezuelos Cobo; José Luis Maté-Muñoz; Manuel V Garnacho-Castaño Journal: PLoS One Date: 2019-05-21 Impact factor: 3.240