Masters Degrees (Exercise, Sport and Lifestyle Medicine)
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Browsing Masters Degrees (Exercise, Sport and Lifestyle Medicine) by Author "Basson, Kyle"
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- ItemHemodynamic changes in recreational cyclists following a long and a short interval high intensity cycling intervention(Stellenbosch : Stellenbosch University, 2019-12) Basson, Kyle; Terblanche, Elmarie; Stellenbosch University. Faculty of Medicine and Health Sciences. Dept. of Sport Science.ENGLISH ABSTRACT: The incorporation of high intensity interval training (HIIT) sessions into training plan is becoming increasingly popular due to the multitude of physiological benefits and time efficient nature of the training method. The physiological changes and specific adaptation pathways which follow the different variations of HIIT programmes is not fully understood. It was expected that the short interval HIT programme would be more successful in the improvement of hemodynamics in comparison to the long interval HIT. In addition that the short interval HIT would also improve aerobic and anaerobic ([La] buffering) metabolic performance parameters to a greater extent. The present study used a similar HIIT programme as previously used (Rønnestad et al., 2015). The previously used training programme was adapted to ensure the recreational cyclists (current study) were able to complete the programme. The two HIIT programmes were performed for the same work duration and the same sRPE, to ensure an equal training load (Inoue et al., 2016). In addition, the use of a high RPE simulates the typical intensity that majority athletes train in real world settings (Seiler et al., 2013). The sixteen recreational cyclists who participated in the study were 21.9 (± 2.75) years old, the range was 18 - 27 years. On average, the participants had 5.1 (± 2.92) years cycling experience. The participants trained on average of 7.3 (± 1.94) hours per week between both groups and ranged from four to ten hours a week before the start of the HIIT programme. In the pre-test phase before the HIIT programme, the average participant’s mass was 77.3 ± 7.79kg and the average %BF was 11.0 ± 2.86% at the beginning of the trial. The changes following the two HIIT programmes were assessed through the peripheral blood content (Δ[O2Hb] and Δ[HHb]), the aerobic performance parameters (VO2max, O2 pulse, PPO and PO at OBLA) and lastly the anaerobic parameters were assessed during a repeated Wingate test ([La]max, PPO and %PR). The measurements of the hemodynamic changes were done with the use of near infrared spectroscopy (NIRS). The short interval HIT programme was more effective in the improvement of eight out of the eleven aerobic performance markers in comparison to the long interval HIT programme. The short interval HIT programme improved the Δ[O2Hb] in the periphery during exercise. In contrast, the long interval HIT was more effective in the improvement of increased blood [La] accumulation following training. It was found that the short interval HIT programme showed improvements in the increased O2 availability in the periphery, the changes were suggested to be associated with central adaptations. The long interval HIT showed increased extraction of O2 at OBLA, the improvements were suggested as mostly peripheral adaptations. The findings of the present study suggest that two similar HIIT programmes (which were matched for training load) showed different adaptation pathways provides an explanation for the differences in magnitude of changes seen. The changes associated to central adaptations were more pronounced following the six week training programme than the peripheral adaptations, as peripheral changes require a longer duration of training.