TY - JOUR
T1 - Cardiorespiratory responses to cycle exercise during a low-intensity sinusoidal work rate
AU - Borrelli, M.
AU - Shokohyar, S.
AU - Rampichini, S.
AU - Bruseghini, Paolo
AU - Doria, C.
AU - Limonta, E.
AU - Longo, S.
AU - Coratella, G.
AU - Montaruli, A.
AU - Ce`, E.
AU - Ferretti, G.
AU - Esposito, F.
PY - 2019
Y1 - 2019
N2 - Purpose: Sinusoidal varying protocols have been recently re-proposed
in assessing the cardiorespiratory response (CRR) to exercise to
reflect the variability in long-lasting physical activities. Contrary to
square-wave tests, the cyclic nature of sinusoidal work rate allows to explore the CRR kinetics several times. Previous studies used to
overlap CRR of successive periods; however, so far no study assessed
whether CRRs are constant along different cycles. Therefore, this
study aimed at investigating the CRR during an exhausting low-intensity
sinusoidal work rate.
Methods: Seven subjects (age: 27 ± 7 yr, body mass: 72.5 ± 6.7 kg;
stature: 1.8 ± 0.1 m) participated to the study. After determining on
different days the maximum oxygen uptake (V’O2max) by ramp
cycle ergometric test and critical power (CP) via different submaximal
exercises, they underwent a sinusoidal work rate until exhaustion.
The exercise varied according to a sinewave function with a midpoint
(MP) equal to 50 W below CP (CP-50), an amplitude (A) of 50 W
and a period of 4 min. Expiratory ventilation (V’E), carbon dioxide
output (V’CO2), oxygen uptake (V’O2) and heart rate (HR) were
obtained breath-by-breath and fitted off-line by the sinewave functions
that minimized the residuals. Thereafter, A, MP and the timedelay
(tD, the latency between mechanical and CRR signals) were
obtained for each cycle. A one-way ANOVA for repeated measures
was applied to test the effect of fatigue.
Results: MP of V’E, V’O2 and HR significantly increased as well as
A of V’E and V’CO2 (p\0.05 for all parameters). On the contrary,
A of HR decreased during the test (p\0.05). No changes were
detected on tD in all CRRs parameters.
Conclusions: This study demonstrates that despite the low intensity
level of the sinusoidal protocol, the dynamics of CRRs are not constant.
Therefore, averaging the CRRs of different cycles might
introduce a bias in the outcomes concealing a marked change in
CRRs.
References
1. Fukuoka Y et al. (2002) Dynamics of the heart rate response to
sinusoidal work in humans: influence of physical activity and age.
Clinical Science 102: 31–38
2. Miyamoto Y et al. (1983) Cardiorespiratory Dynamics during
Sinusoidal and Impulse Exercise in Man. The Japanese Journal of
Physiology 33: 971-986
AB - Purpose: Sinusoidal varying protocols have been recently re-proposed
in assessing the cardiorespiratory response (CRR) to exercise to
reflect the variability in long-lasting physical activities. Contrary to
square-wave tests, the cyclic nature of sinusoidal work rate allows to explore the CRR kinetics several times. Previous studies used to
overlap CRR of successive periods; however, so far no study assessed
whether CRRs are constant along different cycles. Therefore, this
study aimed at investigating the CRR during an exhausting low-intensity
sinusoidal work rate.
Methods: Seven subjects (age: 27 ± 7 yr, body mass: 72.5 ± 6.7 kg;
stature: 1.8 ± 0.1 m) participated to the study. After determining on
different days the maximum oxygen uptake (V’O2max) by ramp
cycle ergometric test and critical power (CP) via different submaximal
exercises, they underwent a sinusoidal work rate until exhaustion.
The exercise varied according to a sinewave function with a midpoint
(MP) equal to 50 W below CP (CP-50), an amplitude (A) of 50 W
and a period of 4 min. Expiratory ventilation (V’E), carbon dioxide
output (V’CO2), oxygen uptake (V’O2) and heart rate (HR) were
obtained breath-by-breath and fitted off-line by the sinewave functions
that minimized the residuals. Thereafter, A, MP and the timedelay
(tD, the latency between mechanical and CRR signals) were
obtained for each cycle. A one-way ANOVA for repeated measures
was applied to test the effect of fatigue.
Results: MP of V’E, V’O2 and HR significantly increased as well as
A of V’E and V’CO2 (p\0.05 for all parameters). On the contrary,
A of HR decreased during the test (p\0.05). No changes were
detected on tD in all CRRs parameters.
Conclusions: This study demonstrates that despite the low intensity
level of the sinusoidal protocol, the dynamics of CRRs are not constant.
Therefore, averaging the CRRs of different cycles might
introduce a bias in the outcomes concealing a marked change in
CRRs.
References
1. Fukuoka Y et al. (2002) Dynamics of the heart rate response to
sinusoidal work in humans: influence of physical activity and age.
Clinical Science 102: 31–38
2. Miyamoto Y et al. (1983) Cardiorespiratory Dynamics during
Sinusoidal and Impulse Exercise in Man. The Japanese Journal of
Physiology 33: 971-986
KW - Cardiorespiratory responses
KW - sinusoidal work
KW - Cardiorespiratory responses
KW - sinusoidal work
UR - http://hdl.handle.net/10807/215675
M3 - Conference article
SN - 1824-7490
SP - 8
EP - 8
JO - Sport Sciences for Health
JF - Sport Sciences for Health
T2 - SISMES XI NATIONAL CONGRESS
Y2 - 27 September 2019 through 29 September 2019
ER -