This study aimed to analyze the impact of step-duration protocols, 1-min vs. 3-min, on cardiorespiratory responses to exercise, whatever the aerobic-fitness level of sedentary (65.5 ± 2.3 years, n = 8) or highly fit (63.1 ± 3.2 years, n = 19) participants. Heart rate and VO2 at the first and second ventilatory thresholds (VT1, VT2) and maximal exercise were not significantly different between the two protocols. In master athletes, the 3-min protocol elicited significantly lower ventilation at VT2 and maximal exercise (p < .01). In the latter, breathlessness was also lower at maximal exercise (p < .05) than in sedentary participants. In trained or sedentary older adults, VT1, VT2, and VO2max were not influenced by stage duration. According to the lower breathlessness and ventilation, however, the 3-min step protocol could be more appropriate in master athletes. In untrained participants, because the cardiorespiratory responses were similar with the two incremental exercise tests, either of them could be used.
Fabien Deruelle, Cédric Nourry, Patrick Mucci, Frédéric Bart, Jean-Marie Grosbois, Ghislaine Lensel and Claudine Fabre
Erwan Leclair, Delphine Thevenet, Sophie C. Reguem, Benoit Borel, Georges Baquet, Serge Berthoin and Patrick Mucci
This study was designed to test the reproducibility of muscle oxygenation by NIRS in children during exercise. Twelve healthy non-obese and non-trained children performed one maximal graded test, and four 6-min constant load cycle exercises. Deoxy-hemoglobin (Hb/Mb-H+) data were averaged every 1, 5, 10, 20 and 30s. Hb/Mb-H+ data averaged every 5, 10, 20 and 30s showed good reproducibility. When averaged every second, Hb/Mb-H+ values were reproducible after the first minute of exercise. Based on 1s averaged signal modeling, time period and t values for Hb/Mb-H+ were not reproducible but mean response time values showed an acceptable reproducibility.
Erwan Leclair, Benoit Borel, Delphine Thevenet, Georges Baquet, Patrick Mucci and Serge Berthoin
This study first aimed to compare critical power (CP) and anaerobic work capacity (AWC), to laboratory standard evaluation methods such as maximal oxygen uptake (V̇O2max) and maximal accumulated oxygen deficit (MAOD). Secondly, this study compared child and adult CP and AWC values. Subjects performed a maximal graded test to determine V̇O2max and maximal aerobic power (MAP); and four constant load exercises. In children, CP (W.kg−1) was related to V̇O2max (ml.kg−1.min−1; r = .68; p = .004). AWC (J.kg−1) in children was related to MAOD (r = .58; p = .018). Children presented lower AWC (J.kg−1; p = .001) than adults, but similar CP (%MAP) values. CP (%MAP and W.kg−1) and AWC (J.kg−1) were significantly related to laboratory standard evaluation methods but low correlation indicated that they cannot be used interchangeably. CP (%MAP) was similar in children and adults, but AWC (J.kg−1) was significantly lower in children. These conclusions support existing knowledge related to child-adults characteristics.