Evidências atuais e perspectivas futuras sobre a distribuição da intensidade do treinamento, volume e prescrição do exercício para corredores de média e longa distância

Abstract

Training-intensity distribution (TID) is considered a key factor to optimize endurance performance. To prescribe and quantify endurance training, a graded exercise test is typically used to determine running speed and/or heart rate associated with physiological benchmarks such as 1st lactate/ventilatory threshold (LT1/VT1) and 2nd lactate/ventilatory threshold (LT2/VT2). Additionally, other methods of prescription and quantification derived from the session-rating of perceived exertion session (s-RPE) and race pace without the need for a graded exercise test can also be used. Recent studies have shown that training quantification through subjective and objective methods may significantly affect TID calculation, making it difficult to establish a quantification model based on s-RPE. Although graded exercise test associated with physiological thresholds is seen as more reliable, its use requires sophisticated equipment, making its use unfeasible during training and/or competitions. In this line, a probable association between physiological thresholds and perceived exertion (RPE) during a graded exercise test could help coaches prescribe training for endurance runners through a noninvasive tool of low-cost and low-complexity. Three training-intensity zones (i.e., zone 1 [4mmol.L -1 ;>LT2;>VT2; s-RPE 7-10]) are used to distribute overall training volume. Middle- and long-distance runners use three main types of TID: 1) Polarized TID with 75-80% of overall training volume in zone 1, 0-5% in zone 2 and 15-20% in zones; 2) Pyramidal TID with 80% of overall training volume in zone 1 and 20% in zone 2 and; 3) TID at threshold with >20% of overall training volume in zone 2. Due to the increase in the number of researches related to TID on middle- and long-distance runners in the last 20 years, there is a need to summarize and systematize the evidence available in specific literature. Thus, the primary objective of this thesis was performing a systematic review (study 1) "Training-intensity on middle- and long-distance runners: A systematic review", and based on its results, as a secondary and tertiary objective performing an experimental study (study 2) "Training-intensity distribution and time-trial performance in long-distance runners: A comparison between objective vs. subjective quantification methods”, and an acute effect study (study 3) “Anaerobic threshold prediction using the OMNI-Walk/Run scale in long-distance runners: A preliminary study”, respectively. Systematic review results (study 1) demonstrated that the quantification method (i.e., s-RPE, blood lactate, heart rate, running speed, and race pace) substantially influence TID calculation. Polarized and pyramidal models produce the best endurance performance compared to threshold model. Therefore, it seems that a combination of high-volume at low-intensity (≥ 70% of overall training volume) and low-volume at highintensity (≤ 30%) is needed to improve endurance performance. Furthermore, monitoring training through multiple mechanisms using subjective and objective methods can help coaches make better decisions. Regarding the experimental study (study 2), the results showed that running speed yielded a polarized TID (zone 1: 78.09 ± 2.92%, zone 2: 4.97 ± 1.97%, zone 3: 16, 71 ± 2.37%), while s-RPE resulted in a high intensity TID (zone 1: 31.92 ± 18.20%, zone 2: 19.29 ± 14.63%, zone 3: 48.74 ± 18.08%). Running speed also demonstrated greater total training time spent in zone 1 compared to s-RPE, while the opposite was verified for s-RPE when compared to running speed in zones 2 and 3 (p <0.001). A significant improvement in performance was observed after an 8-week polarized TID [Pre: 2504 ± 164 vs. Post: 2425 ± 135 sec (p <0.001)] ]. Acute effect study results (study 3) showed no significant difference in running speed in which lactate threshold determined by Dmax method (LTDmax) [13.53 ± 0.96 km·h-1 ] and rating of perceived exertion threshold determined by Dmax method (RPETDmax) [13.47 ± 1.05 km·h-1 ] were found (p=0.664). Moreover, both methods showed a strong correlation (r=0.91) and agreement through the Bland-Altman plot analysis.