Summary:
Abstract
Physiological and molecular responses for high intensity interval training in flat water kayak athletes.
Introduction
For physical condition and sport performance improvement, high intensity interval training (HIIT) seems to be more effective from continuous training (CT). HIIT uses loads in about 90%VO2peak or more. Continuous training uses loads in about 70-85% VO2peak. In sprint kayak the training methods uses HIIT in lower distances than the racing (1000,500,200m), in order to improve aerobic and anaerobic performance. C.T seems to improve the same physiological variables in lower intensities using larger amount of exercise time.
Methods
6 healthy subjects volunteered to participated to this study (age 18±4 years, weight 71 ±± 11,53kgr, height 171,5 ±± 8,73cm). All participants had participated to the national championships with four years of training experience. The purpose of the study was to investigate the adaptations of HIIT 8X30 s 120% VO2peak with 60 s passive recovery. The incremental VO2peak test took place before T1 and after T2 the 8-weektraining period. A kayak ergometer type stroke to max (south Africa) used for the training sessions, the incremental test and the anaerobic type Wingate test. The variables measured were VO2peak, PSVO2peak, PSVT2, PE, HRpeak, [La+2]. In mRNA level we calculated using real time PCR the genes IGF1Ea, IGF1Eb, IGF1Ec, TGF-β, VEGF-a and also we calculated using elisa IGF1, GH, For the statistical analyses we used the medians and the standard error. For the comparison of the medians we used Wilcoxon parametric t-test, with p≤0,05 level of convenience, was performed to identify differences between physiological and molecular responses.
Results
HIIT training cycles resulted in various, gains in IGF1 (312,27±68,7 vs 313,92±56,17), GH(1663,68±1455,65Vs 771,65 ±1148,36),IGF1-Ea (1 vs5,995±5,1), IGF1Εb (1 vs 38,7± 57,7), IGF1-Ec (1 vs 41,3±65 ), TGF-β (1 vs 7,1 ± 10,6), VEGF-a (1 vs 21,1 ± 41,5 )
HIIT training cycles resulted in various, gains in VO2peak (46,96 ± 5,45 vs47,85 ± 3,37), PSVT2 ( 11,1 ± 0,53Vs11,6 ±0,1), PSVO2peak ( 12,86 ±1,23vs 13,375 ±0,80), PE ( 9,265 ± 0,8 vs 9,466 ± 0,55 ), [La+2]peak ( 13,8 ± 2,78 vs 14,74 ±3,14), HRpeak ( 193 ± 10,17vs 193,16 ± 10,2)
Conclusions
These findings suggest that HIIT training programs resulted in improvements of selected physiological and molecular variables. The HIIT method led to higher improvements with less training time compared to traditional methods. Thus, that HIIT may be more effective for improving performance of national-level kayakers. a HIIT training cycle could be a more useful, time-effective tacticfor achieving greater improvements in certain variables related to kayaking performance.
Keywords:
HIIT: High intensity interval training, GH:Growth Hormone, IGF-1: (Insulin-like Growth Factor 1, VEGF-a:(Vascular Endothelial Growth Factor), TGF-β :Transforming Growth Factor, IGF-1Ea: Insulin-like Growth Factor isomorph Ea, IGF-1Eb:Insulin-like Growth Factor isomorph Eb, IGF1Ec:Insulin like Growth Factor isomorph Ec, VO2peak: peak oxygen uptake, [La+2]: lactate accumulation, PSVO2peak: s Paddling speed in peak oxygen uptake, PSE: Paddling speed economy, PSVT2: anaerobic threshold, HRpeak: peak heart rate
