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Diss. : Institut für Altertumskunde : Köln. - Bibliogr. p. 173-174. Index. -

Texte remanié de: Diss. doct.--Institut für Altertumskunde--University of Cologne. / texte en anglais, citations en grec ancien. Bibliogr. p. 173-174. Index.

Thesis (M.A.)--Brock University, 2007. / Includes bibliographical references (leaves 81-92).

Training is a complex, multi-factorial process, which involves the manipulation of the duration, frequency and intensity of exercise. When quantifying the physiological and performance responses to training a large inter-individual variability in training responses is frequently observed. To date, the majority of research has examined the relationship between genetics and trainability. Another hypothesis, which has not been fully explored, is that the variability is also due to an inappropriate standardisation of exercise intensity or duration. This thesis, therefore, presents a series of studies that investigate the effects of individualised methods of prescribing exercise intensity and duration on performance and physiological responses in cycling. Study 1 compared time-to-exhaustion (TTE) to time-trial (TT) performances when the duration of the trials were matched and participants were blinded to feedback. A higher mean power output was found for TTE compared to TT at 80% (294 ± 44 W vs. 282 ± 43 W respectively, P < 0.05), but not at 100% (353 ± 62 W vs. 359 ± 74 W) and 105% (373 ± 63 W vs. 374 ± 61 W) of maximum aerobic power (MAP). Critical power (CP) calculated from the TTE trials was also higher, whereas, anaerobic work capacity (W′) was lower (P < 0.05). The findings favour TTE over TT performances for a higher mean power output and calculated CP. Study 2 compared the effects of three training intensities: moderate intensity (MOD), high intensity (HIT) and a combination of the two (MIX) when the duration of exercise was individualised. Participants were randomly assigned to one training group and trained 4 times per week for 4-weeks. Training duration was individualised to each participant’s maximum performance. All training groups increased maximal oxygen uptake (V̇O2max), MAP, TTE and gross efficiency (GE) after training (P < 0.05), but no differences were observed between groups (P > 0.05). Therefore, when the duration of training is individualised, similar improvements in performance and physiological responses are found, despite differences in exercise intensity. The CP and power law models propose power-duration relationships that describe maximum endurance capacity. Study 3 compared the predictive ability of these two models for TTE performances. It was hypothesised that the CP and power law models would reliably predict actual TTE for intensities between 80-110% MAP, but a power law model would better predict TTE for intensities outside of this range. No significant differences for parameter estimates were found between models (CP and power law) and actual TTE for intensities ranging from 80-110% MAP. Outside of this range however, the CP model over predicted actual performance at 60% and 150% MAP (P < 0.05), while there was no significant difference between the power law model and actual performance at these intensities (P > 0.05). Both models were different from actual performance at 200% MAP (P < 0.05). Therefore, a power law model can accurately predict cycling TTE for intensities ranging from 60-150% MAP. Study 4 tested the hypothesis that the inter-individual variability for TTE performances is due to the methods used to standardise exercise intensity. A %V̇O2max prescription was compared with an alternative based on an individual power-duration relationship (using a power law model). A power law model predicted the intensity for TTE lasting exactly 20-min and 3-min. A corresponding intensity for TTE as a %V̇O2max was 88% and 109%. On two separate occasions participants completed two TTE trials using the power law and %V̇O2max prescriptions, with 30-min rest between trials. There was a significant reduction in the inter-individual variability for TTE when exercise was prescribed using a 20-min power law versus 88% V̇O2max prescription method (coefficient of variation = 29.7 vs. 59.9% respectively; P < 0.05). However, there was no significant difference in the inter-individual variability for TTE using a 3-min power law versus 109% V̇O2max prescription method (P > 0.05). Two main conclusions can be drawn from this thesis. Firstly, a power law model can accurately predict and describe cycling endurance performance across a wide range of intensities. Secondly, prescribing exercise intensity using a power law model reduces the variability in TTE by 50% when compared to a %V̇O2max prescription method. Therefore, the methods used to standardise exercise intensity appear to be related to the variability in TTE performances. Future research should examine whether training prescribed using a power law model reduces the variability in subsequent training responses.

The aims of this thesis were to develop a time efficient field test of the distance-time relationship, assess its validity, reliability and sensitivity and utilise the test to monitor and prescribe endurance training in distance runners. Laboratory-based tests of the distance-time relationship often use lengthy recovery periods between trials, resulting in multiple visits and limiting their practical application. A field-based test, completed in a single visit, could improve the utility of the distance-time relationship. A novel single visit field test comprising of 3 constant-distance trials, separated by a 30-minute recovery, was designed. This test estimates the highest sustainable rate of aerobic metabolism, or critical speed (CS), and the modelled maximum distance performed above CS (D’). When compared to a traditional multi-visit laboratory protocol, field test CS was highly correlated (r=0.89, P0.05) and high typical error (334-1709 s). Non-linear modelling of recovery did not improve the accuracy. A high variability in D’ may in part explain the low predictive ability of the models. The conclusion from this thesis is that the single visit field test is a valid, reliable and sensitive test for CS, which provides a favourable alternative to multi-visit laboratory-based testing.

Limited research data is available outlining the resistance training characteristics of elite football players. The aim of the first study (Chapter 3) was to compare approaches to calculating resistance training volume during 4 weeks of pre-season training in 23 English Premier League footballers. Volume was calculated using four different methods of quantification; Repetition volume (RV), Set Volume (SV), Volume Load (VL) and Maximum Dynamic Strength Volume Load (MDSVL). Overall there was a significant difference between resistance training volumes calculated by the different methods used to monitor resistance training load (P < 0.001). More specifically, significant differences were observed between RV and SV methods (P < 0.001), RV and MDSVL (P = 0.001), SV and VL (P = 0.010), SV and MDSVL (P = 0.033) and VL and MDSVL (P = 0.002). Only RV and VL methods were similar in the information they provided on training load (P = 0.411). While the lack of a gold standard measure of volume makes it is unclear which, if any, method represents the most accurate measure of volume the discrepancies between methodological approaches highlight that these different approaches are not directly transferable as strategies to monitor resistance training. The understanding of the differences between each method may therefore enable appropriate, situation specific, approaches to be designed and implemented for both practical and research purposes. The aim of the second study (Chapter 4) was to analyse the resistance training loads completed by an elite professional football team across a competitive season. Resistance training data was collected from 31 elite football players competing in the English Premier League over a 46 week period in the 2012-2013 season. A total of 1685 individual training observations were collected during the pre-season and in-season competition phases, with a median of 42 training sessions per player (range = 9 – 124). Training load data was separated into 7 blocks of 6 weeks for analysis. These periods included pre-season (6 weeks duration) and in-season (40 weeks duration) phases. Set volume was selected as a measure of total volume. Data was analysed using 3 separate linear mixed modelling analysis using the statistical software package R (Version 3.0.1). Weekly resistance training frequency (mean±SD) ranged from 1±1 to 2±1 sessions per week during the pre and in season phases. Significant differences in session frequency were seen between weeks 1-6 and weeks 7-12 (pre-season) (P ˂ 0.05), weeks 7-12 and weeks 13-18 (P ˂ 0.05), and weeks 7-12 and weeks 37-42 (P ˂ 0.05). Mean weekly training volume ranged from 18±16 to 30±24 sets.wk-1. The total training volume demonstrates a clear minimum during weeks 7-12. Significant differences in total training volume were also observed between weeks 1-6 and weeks 7-12 (pre-season) (P ˂ 0.01), weeks 7-12 and weeks 13-18 (P ˂ 0.05), and weeks 7-12 and weeks 19-24 (P ˂ 0.05). There was no significant difference in training intensity between weeks 1-6 (pre-season) and weeks 7-12. Training intensity during weeks 1-6 however was significantly lower than during weeks 13-18 (P ˂ 0.05), 19-24 (P ˂ 0.01), 25-30 (P ˂ 0.01), 31-36 (P ˂ 0.05), and 37-42 (P ˂ 0.01). Training intensity during weeks 7-12 was also significantly lower than during weeks 13-18 (P ˂ 0.01), 19-24 (P ˂ 0.05), 25-30 (P ˂ 0.05), 31-36 (P ˂ 0.05), and 37-42 (P ˂ 0.001). The findings would suggest that resistance training loading is limited during different periods of the season. This is predominantly as a consequence of low training frequency, potentially due to a high prevalence of competitive fixtures. The aim of the third study (Chapter 5) was to attempt to quantify the impact of resistance training completed by players, through evaluating the change in the lower body power outputs of an elite professional football team across a competitive season. Resistance training data was collected from 22 elite football players competing in the English Premier League over a 38 week period. A total of 246 individual power output observations were collected during the in-season competition phase. Power output of the lower body was assessed using a pneumatic resistance leg press machine with software and digital display (Keiser Sports Health Equipment Inc., Fresno, Ca). Data was analysed by means of linear mixed modelling analysis using the statistical software package R (Version 3.0.1). Power outputs ranged from 2200W to 4078W with a mean value of 3022±374W. Linear mixed effects show a significant effect of week on power output across the season (coefficient= 7.76W, p=0.0132). Specifically, when accounting for within player effects, power output increased 7.76W per week during the season. Individual weekly power coefficients ranged from +39.9W to -18.13W per week, thus indicating that the trend for increased power output across the season is not uniform for all the players. These data may suggest that lower body power performance is maintained or minimally enhanced over the course of a full competitive season in elite football players. Combined with the training load data previously examined in this thesis it can be concluded that whilst one resistance training session per week may be sufficient to avoid in season de-training or minimally improve power performance in elite football players, a frequency of two sessions per week may be necessary to obtain significant performance enhancements. In our fourth study (Chapter 6) we provide two case studies that outline and evaluate a structured approach to increasing resistance training loading with the primary goal of developing strength and power during the competitive season in elite football players. The purpose of our initial case was to examine a resistance training programme to enhance strength and power performance, alongside body composition during a period of rehabilitation from injury. The study intervention commenced following two weeks of recovery following the “Laterjet” surgical procedure. Initial assessments were performed for body composition via dual-energy x-ray absorptiometry (DXA) (QDR Series Discovery A, Hologic Inc., Bedford, MA) and lower body power output via using a pneumatic resistance leg press machine with software and digital display (Keiser Sports Health Equipment Inc., Fresno, Ca). Assessments were repeated 8 weeks post-surgery, i.e. following 6 weeks of resistance training. The six-week intervention consisted of three strength training sessions per week for the initial 3 weeks, followed by 2 sessions per week for the subsequent 3 weeks. Training volume (number of sets) equalled a total of 20 sets total per session. Total increase in body mass over the intervention period equated to 5.4kg, of which 4.2 kg increase in lean mass and a 1.3 kg increase in fat mass. Peak power output increased by 21%. Power to weight ratio also increased by 4.4 %. These data illustrate that it is possible to increase physical performance when rapid short-term increase in resistance training load is completed. The purpose of our second case was to examine a resistance training programme to enhance both strength and power performance parameters during a full competitive season. The player plays as a goalkeeper, regularly playing for his club 1st team. Prior to the onset of this case study this player did not present with any current injuries. This season long intervention consisted of two phases of training. Phase 1 was 16 weeks in duration and represented the beginning to the mid-point of the season. During this phase the goal was to gradually and safely increase resistance training loading. Phase 2 was 20 weeks in duration and represented the mid-point to the end of the season. This phase represented a period of consistent high loading following the initial systematic increase in these variables. / Assessment data was collected at the beginning, mid-point and end of the 2013-14 season. The player was first assessed for body composition via DXA (QDR Series Discovery A, Hologic Inc., Bedford, MA). Secondly, lower body power output was assessed using a pneumatic resistance leg press machine with software and digital display (Keiser Sports Health Equipment Inc., Fresno, Ca). Finally, the player’s upper body strength was assessed via 6 repetition maximum assessments of the dumbell bench press and prone row. The player completed a mean weekly volume of 41±24 sets per week and a mean frequency of 2±1 sessions per week for the initial phase of the study. The player completed a greater mean weekly volume in the later phase of the season compared to the initial training period (65±28 set per week vs. 41±24 sets per week in the initial phase of the season). A greater mean session frequency was also associated with the second training phase (3±1 vs. 2±1 session per week). There was a total decrease in body mass over the initial intervention period of 4kg, of which 2.7kg decrease in fat mass and a further 0.9 kg decrease in lean mass. Over the second phase of the intervention there was a total increase in body mass of 1.2kg, of which 2.4kg increase in lean mass and 1.2kg decrease in fat mass. During the initial phase of training peak power output increased by 25%, whilst power to weight ratio increased by 30%. During the later phase peak power output increased by a further 9% whilst the power to weight ratio increased by a further 10%. Upper body pressing (Dumbell Bench press) and upper body pulling (Dumbell Prone pull) strength was also increased by 14% and 21% respectively during the initial phase and a further 19% and 24% respectively during the later phase of the season.

Summaries in Afrikaans and English / Die primere doel van hierdie ondersoek was om vas te stel hoe belangrik dit is dat 'n komponent sportsielkunde ingesluit word in die opleidingsprogram van vakonderwysers. Ten einde hierdie doel te bereik, is 'n teoretiese sowel as 'n empiriese ondersoek uitgevoer. Tydens die teoretiese ondersoek is verskillende aspekte van die sportsielkunde ontleed, waarin die rol van die vakonderwyser telkens toegelig is. Tydens die empiriese ondersoek (waaraan 134 vakonderwysers wat sport afrig en 235 sportleerlinge deelgeneem het) is aangetoon dat: Ongeveer 82% van die vakonderwysers wat sport afrig, opleiding in afrigtingstegnieke ontvang het, maar slegs 16% het opleiding in sportsielkunde ontvang. • Vakonderwysers daarvan oortuig is dat sportsielkunde ingesluit moet word in die opleidingsprogram van vakonderwysers. • Dit vir sportleerlinge baie belangrik is dat sportmanne en -vroue vertroud moet wees met bepaalde aspekte van sportsielkunde en dat hulle afrigters kennis moet dra van sportsielkunde. 'n Aspek soos motivering in sport baie belangrik geag word deur onderwysers sowel as sportleerlinge, terwyl angs in sport en aggressie in sport heelwat laer op die ranglys verskyn. / It was the primary aim of this investigation to establish how important it is that a component of sport psychology be included in the training programme of subject teachers. In order to achieve this goal, a theoretical as well as an empirical investigation were conducted. During the literature study, different aspects of sport psychology were analyzed and the role of the teacher was highlighted in each instance. During the empirical study ( in which 134 subject teachers and 235 sport pupils participated) it was indicated that; Approximately 82% of the subject teachers coaching sport, had received training in coaching techniques, but only 16% had received training in sport psychology. Subject teachers are convinced that sport psychology should be included in the training programme of subject teachers. Pupils participating in sport regard it as very important that sportsmen and - women should be acquainted with certain aspects of sport psychology and that their coaches should bear knowledge of sport psychology. An aspect such as motivation in sport is regarded as being very important by teachers and sport pupils, while anxiety in sport and aggression in sport appear much lower on the rating scale. / Educational Studies / M.Ed. (met spesialisering in Voorligting)

Delayed onset muscle soreness (DOMS) is a muscle strain injury that presents as tender or aching muscles, often felt during palpation or movement. DOMS is associated with unaccustomed, high-force muscular work and is most pronounced if the work involves a significant eccentric component. Despite substantial research into DOMS its aetiology is still unresolved. There have been recent suggestions that reactive oxygen species (ROS) may be involved in the aetiology of DOMS, however the evidence for this association is equivocal. Therefore, the aims of this thesis were to investigate the effects of unaccustomed exercise (downhill running) on DOMS, specifically investigating the role of ROS in its aetiology. Once this had been established, the effects of dietary intervention and antioxidant supplementation on DOMS and ROS were also investigated. Study 1 demonstrated that downhill running, which resulted in DOMS, also induced the production of ROS, detected by ESR spectroscopy as well as an increases in serum malondialdehyde (MDA) concentration. It was noted that this increase in ROS occurred -72 h post exercise and was therefore likely to be a result of increased phagocyte activity. Furthermore, the increase in ROS occurred after peak DOMS and when muscle function (as determined by losses of muscle torque assessed by isokinetic dynamometry) was returning to pre-exercise levels, suggesting a temporal dissociation between ROS production and DOMS following downhill running. Circulating levels of ROS were still increasing 72 h post exercise so this study was unable to map the full time-course of ROS production following downhill running. Study 2 investigated the effects of dietary CHO intake on DOMS, ROS and muscle function. It was found that pre-exercise CHO status had no effect on ROS production, DOMS or losses of muscle function following downhill running. The study demonstrated a bi-phasic increase in creatine kinase (CK), with the second increase corresponding with the post-exercise ROS production. The study extended the postexercise sampling period to 96 h, however, ROS were still increasing at this time and therefore this study was also unable to conclude a definitive tune course of ROS production following downhill running. Study 3 demonstrated that prolonged ascorbic acid supplementation attenuated the post-exercise increase in ROS production compared to placebo. This attenuation in ROS prevented the secondary peak in CK activity, however it had no effect on DOMS. Interestingly, supplementation with ascorbic acid resulted in more prolonged losses of muscle function. ROS peaked at 96 h post exercise and therefore the time course ofROS production following downhill running was established. From these studies it was concluded that downhill running did result in post-exercise ROS production. This post-exercise ROS production was associated with secondary muscle damage as measured by plasma CK activity although it had no effect on DOMS. Since supplementation with ascorbic acid attenuated ROS production and prolonged the losses of muscle function, it was suggested that ROS produced by phagocytes m the days following muscle-damaging exercise have a positive role in assisting in the recovery from the trauma.