Physiological Responses During High-Intensity Interval Training in Young Swimmers

Abstract

This study analyzed whether 100- and 200-m interval training (IT) in swimming differed regarding temporal, perceptual, and physiological responses. The IT was performed at maximal aerobic velocity (MAV) until exhaustion and time spent near to maximalVO2 peak oxygen uptake (⩒O2peak), total time limit (tLim), peak blood lactate [La−] peak, ⩒O2 kinetics (⩒O2K), and rate of perceived exertion (RPE) were compared between protocols. Twelve swimmers (seven males 16.1 ± 1.1 and five females 14.2 ± 1 years) completed a discontinuous incremental step test for the second ventilatory threshold (VT2), ⩒O2peak, and MAV assessment. The swimmers subsequently completed two IT protocols at MAV with 100- and 200-m bouts to determine the maximal ⩒O2 (peak-⩒O2) and time spent ≥VT2, 90, and 95% of ⩒O2peak for the entire protocols (IT100 and IT200) and during the first 800-m of each protocol (IT8x100 and IT4x200). A portable apparatus (K4b2) sampled gas exchange through a snorkel and an underwater led signal controlled the velocity. RPE was also recorded. The Peak-⩒O2 attained during IT8x100 and IT4x200 (57.3 ± 4.9 vs. 57.2 ± 4.6 ml·kg−1·min−1) were not different between protocols (p = 0.98) nor to ⩒O2peak (59.2 ± 4.2 ml·kg−1·min−1, p = 0.37). The time constant of ⩒O2K (24.9 ± 8.4 vs. 25.1 ± 6.3-s, p = 0.67) and [La−] peak (7.9 ± 3.4 and 8.7 ± 1.5 mmol·L−1, p = 0.15) also did not differ between IT100 and IT200. The time spent ≥VT2, 90, and 95%⩒O2peak were also not different between IT8x100 and IT4x200 (p = 0.93, 0.63, and 1.00, respectively). The RPE for IT8x100 was lower than that for IT4x200 (7.62 ± 2 vs. 9.5 ± 0.7, p = 0.01). Both protocols are considered suitable for aerobic power enhancement, since ⩒O2peak was attained with similar ⩒O2K and sustained with no differences in tLim. However, the fact that only the RPE differed between the IT protocols suggested that coaches should consider that nx100-m/15-s is perceived as less difficult to perform compared with nx200-m/30-s for the first 800-m when managing the best strategy to be implemented for aerobic power training.

Time limit and V̇O2 kinetics at maximal aerobic velocity: Continuous vs. intermittent swimming trials

“…This test was composed of six sets of 250 m, plus one set of 200 m at maximal intensity, with 30 s rest for [La − ] collection (Espada et al, 2015;Almeida et al, 2020Almeida et al, , 2021Massini et al, 2021), in order to allow the determination of maximal oxygen uptake (V _ O 2peak ), VT₂, vVT₂, and MAV. The velocity of the first repetition was set at 50% of the swimmers' 200 m trial velocity (performed 48 h before the beginning of the tests), and increments of 5%-10% were imposed in the remaining repetitions until swimmers' voluntary exhaustion.…”

“…The maximal aerobic velocity (MAV), which corresponds to the minimal velocity at which the maximal oxygen consumption of an athlete occurs, is one of the most important variables of study in sports physiology since it combines exercise economy and maximal V _ O 2 rates into a single factor, being well related with performance (Billat and Koralsztein, 1996;Demarie et al, 2000;Reis et al, 2012;Espada et al, 2015;Almeida et al, 2021). This velocity, associated with the 3,000 m running (Lacour et al, 1990;Demarie et al, 2000) or the 400 m swimming (Espada et al, 2015;Zacca et al, 2019) velocities, is usually used by coaches for training intensity prescriptions (Demarie et al, 2000;Fernandes and Vilas-Boas, 2012;Espada et al, 2015;Zacca et al, 2019Zacca et al, ,2020.…”

“…Therefore, studying the time to exhaustion (t Lim ) at MAV (t Lim -MAV) is extremely important, primarily to provide insightful information regarding the athletes' capacity at this intensity, aiming for better planning of the training sets (Fernandes et al, 2008). Moreover, it is generally accepted that exercise intensities between 70% and 100% of V _ O 2 maximal rates, as well as training sets sustained near V _ O 2 maximal rates have been reported to improve the aerobic power (Billat and Koralsztein, 1996;Demarie et al, 2000;Millet et al, 2003;Almeida et al, 2021), and therefore also improve long term performance (Bentley et al, 2005;Libicz et al, 2005).…”

“…In this sense, faster primary V _ O 2 responses have been associated with higher conditioning levels (Jones and Burnley, 2009;Reis et al, 2012;Espada et al, 2015), as well as related to the time spent near V _ O 2 maximal values during interval training (IT) running sessions (Millet et al, 2003). However, only two studies analyzed continuous V _ O 2 response in IT swimming sessions (Bentley et al, 2005;Almeida et al, 2021).…”

“…The current study aimed to compare physiological responses during two different training modes-continuous (CT) vs. intermittent (IT 100 ) swimming sets both performed until exhaustion (t Lim ), in order to verify the differences regarding the t Lim and times spent near V _ O 2peak . We hypothesize that: 1) both time-limit tests will promote a high V _ O 2 response near V _ O 2 maximal values, and therefore recognize both conditions as suitable schedules for training to improve maximal cardiorespiratory conditioning; 2) the IT 100 will present a higher t Lim and a longer time spent near V _ O 2 maximal values, which is an expectance when considering the recognized effect of IT mode of exercise on reducing metabolites accumulation (Zuniga et al, 2011;Rønnestad & Hansen, 2016;Almeida et al, 2021); and 3) faster V _ O 2 responses will be related with longer times to exhaustion in the time-limit tests, since the assumption relating t Lim to V _ O 2 kinetics considers that fast V _ O 2 response to target muscle O 2 requirements would reduce O 2 deficit and metabolite accumulation, and increase oxidative contribution (Bailey et al, 2009).…”