Masters Degrees (Exercise, Sport and Lifestyle Medicine)

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Browsing Masters Degrees (Exercise, Sport and Lifestyle Medicine) by Subject "Absa Cape Epic mountain bike race -- South Africa -- Psychological aspects"

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    Physiological demands of the Absa Cape Epic mountain bike race and predictors of performance
    (Stellenbosch : Stellenbosch University, 2014-12) Greeff, Marli; Terblanche, Elmarie; Stellenbosch University. Faculty of Education. Dept. of Sport Science.
    ENGLISH ABSTRACT: The purpose of this qualitative-quantitative study was to describe the exercise intensity and predictors of performance of a multi-stage mountain bike (MTB) race (2014 Absa Cape Epic) lasting 8 days. Twenty-three amateur mountain bikers (age 39 ± 9 years, height 178.8 ± 8.2 cm, body mass 74.7 ± 9.1 kg, VO2max 54 ± 7 ml.kg-1.min-1) who completed the 2014 Absa Cape Epic were involved in the study. The participants were divided into two groups according to their MTB experience. The experienced group included participants who previously completed more than three 3-day multi-stage MTB events and the novices group included those who has completed less than 3-day multi-stage MTB events. Prior to the event the participants completed a maximal aerobic cycling test and a simulated 40 km time trial (TT). The maximal aerobic test was used to determine 3 work intensity zones based on heart rate (HR) corresponding to blood lactate thresholds (LT: increase in blood lactate concentration of 1 mmol.l-1 above baseline values and the onset of blood lactate accumulation (OBLA), a fixed blood lactate concentration of 4 mmol.l-1). There were no statistically significant differences in the physical, physiological and performance variables measured in the laboratory between the two groups. The exercise intensity during the Cape Epic was measured using telemetric HR monitoring sets. RPE values were noted after each stage of the race. The mean HR was 88.1 ± 5.3% (experienced) and 84.2 ± 11.0% (novices) of maximal HR during the race or 88.9 ± 3.5% (experienced) and 85.9 ± 10.6 (novices) of laboratory determined maximum HR. More time was spent in the “low” HR zone (43.1 % vs 58.5 %, respectively), while only a small amount of time was spent in the “hard” HR zone (7.4% and 6.1%, respectively). The experienced group spent statistically significantly more time in the “moderate” HR zone compared to the novices group (49.5 % vs. 35.4 %). The experienced group performed significantly better during the event compared to the novices group in both the total event time (P = 0.004) and the general classification (P = 0.01). Relative and absolute power output (PO) at OBLA (P = 0.01 and 0.02, respectively) were statistically significant predictors of total event time, while relative peak power output was a significant predictor of general classification for the event (P = 0.02) . The total TT time was a significant predictor of average event HR (P = 0.03). This study showed that this MTB stage race is physiologically very demanding and requires cyclists to have excellent endurance capacity, as well as strength and power. The parameters from the maximal aerobic capacity test correlated better with outdoor performance than parameters from the simulated 40 km TT. Therefore the standard maximal aerobic capacity test are sufficient for testing mountain bikers and sport scientists can continue using this test to prescribe exercise intensity zones for training and events.