Heart rate dynamics and lactate following high-intensity race-pace continuous vs interval workouts in highly trained athletes

Abstract

PurposeThe present study aimed to compare the physiological responses of high-intensity race-pace continuous vs. interval workouts commonly used in middle-distance athletics, by means of analyzing post-exercise cardiac autonomic regulation and lactate.MethodsNineteen highly-trained 800-m male runners were asked to run a 600-m race-pace continuous workout and a 2 × 4 × 200-m interval training, counterbalanced and randomized within one week of difference. Blood lactate jointly with linear and nonlinear heart rate dynamics were assessed during the immediate 15-min recovery. Age-category (Under23-Senior vs. Juvenile-Junior) was considered as an inter-subject factor.ResultsPeak lactate was higher following the interval training (15.51 ± 0.99 vs 13.83 ± 1.77 mmol L−1; P < 0.05) whereas lactate removal was almost nonexistent 15 min after both workouts (between 0 and 16%). Vagal modulation (ln RMSSD and lnRMSSD to RR ratio) remained significantly depressed at the end of recovery following both workouts, although the alteration was larger following the interval training. Detrended Fluctuation Analysis evidenced a more random HR behavior (DFA1 closer to 0.5) during the first 9 min of recovery after the interval training, whereas no significant change was observed in heart rate complexity (SampEn). Neither were differences found in post-exercise lactate and HR dynamics as a function of age-category.ConclusionsHigh-intensity workouts commonly used in middle-distance athletics, both race-pace continuous and intervallic approaches, induce a large depression of vagal modulation in highly trained runners, although interval trainings appear to induce even a greater alteration of both linear and nonlinear HR dynamics and a higher post-exercise peak lactate.

Acute response of biomarkers in plasma from capillary blood after a strenuous endurance exercise bout

“…Practically, this would mean that blood should not necessarily be obtained from the arm veins, but as plasma from capillary blood from the fingerpick or the earlobe (Siart et al 2019 ). Many athletes are familiar with blood sampling from the earlobe, as this is also where lactate measurements are taken (Faulkner et al 2014 ; Martinez-Navarro et al 2021 ). In addition, taking the blood plasma from this source is more user-friendly, because it represents an easy collection up to 200 uL by a minimally invasive procedure and does not require skilled personnel (Raa et al 2020 ).…”