What question did this study set out to answer?

To evaluate the rapid heart rate dynamics at the onset and cessation of bicycle exercise across various work rates.

April 1, 1985International Journal of Sports Medicine

Fast “ON” and “OFF” Heart Rate Transients at Different Bicycle Exercise Levels

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Population

17 healthy men, mean age 23 +/- 4 years

Design

Other

Follow-up

15 seconds after each work rate change

Authors

CACláudio Gil Soares de AraújoUniversidade do Estado do Rio de Janeiro

Discussion

Member takes

Implication

Hypothesis-generating for vagal HR dynamics in exercise; prospective studies needed before clinical adoption.

Key Points

To evaluate the rapid heart rate dynamics at the onset and cessation of bicycle exercise across various work rates.
Monitored 17 healthy men (mean age 23 ± 4 years) cycling at 60 rpm during workload step increases from 0 to 1, 1 to 2, and 2 to 4 W·kg⁻¹ ('ON'), and decreases from 4 and maximal workload to 0 W·kg⁻¹ ('OFF').
Continuously recorded ECG from 5 seconds before to 15 seconds after workload changes, determining heart rate percent changes at 2.5-second intervals via linear regression.
Evaluated vagal involvement using parasympathetic blockade in two participants and correlated transient dynamics with VO2max derived from a progressive maximal test.
Heart rate shifted rapidly by 10% during ON transitions and by 5% during OFF transitions within 15 seconds, demonstrating consistent individual reproducibility (P > 0.05).
Parasympathetic blockade in tested participants resulted in substantially slower heart rate transients, confirming that rapid exercise adjustments are primarily mediated by the vagus nerve.
No statistically significant correlation was identified between heart rate transient rates and individual VO2max values (P > 0.05).

Structured PICO

Population

17 healthy men, mean age 23 +/- 4 years

Intervention

Bicycle exercise at different work rates (ON transients: 0 to 1, 1 to 2, 2 to 4 W.kg-1; OFF transients: 4 and maximal to 0 W.kg-1)

Outcome

Heart rate changes (delta % HR) at 2.5 s intervals during ON and OFF transientssurrogate

Rapid heart rate changes at the onset and end of exercise are primarily mediated by vagal tone.

Cite This Study

Cláudio Gil Soares de Araújo (1985) studied this question.

synapsesocial.com/papers/6a8bc84290fae8fd47e99261 https://doi.org/10.1055/s-2008-1025815

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Fast “ON” and “OFF” Heart Rate Transients at Different Bicycle Exercise Levels

Discussion

Member takes

Implication

Key Points

Structured PICO

Cite This Study

Fast “ON” and “OFF” Heart Rate Transients at Different Bicycle Exercise Levels

Discussion

Member takes

Implication

Key Points

Structured PICO

Cite This Study

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