Traditional approaches to exercise testing in children may not provide the most appropriate measures of a child's physiological responses to exercise, partly because they do not reflect children's normal intermittent activity patterns. The measurement of the rate and magnitude of change of oxygen uptake to dynamic exercise, oxygen uptake kinetics (V02 KINETICS provides an alternative approach to exercise testing. A submaximal, intermittent, pseudo-random binary sequence (PRBS) exercise test to measure V02 KINETICS may provide a useful method of measuring the metabolic responses of children to exercise. Traditional methods used in the analysis of V02 KINETICS require the fitting of explicit models in order to characterise the data. These models have not however been validated for use in children. As the responses to the PRBS protocol are analysed in the frequency domain, explicit models and their physiological correlates are not required to characterise the data. Another potential problem in the measurement of V02 KINETICS in children are the small work rate changes that can be employed to stimulate the exercise response whilst constraining the test to the aerobic range. In respiratory gas measurement, breath-by-breath variability (noise) can be large in comparison to the magnitude of the metabolic response and this signal noise can obscure some characteristics of the response. The aim of the study was to develop appropriate measurement techniques to reduce the effects of breath-by-breath variability and to apply the techniques to the measurement of V02 KINETICS in children. The main experimental study compared the V02 KINETICS of children with those of adults. Ten children (3 females) in the age range 8 to 13 and twenty adults (10 females) in the age range 20 to 28 years completed a PRBS test to measure V02 KINETICS and an incremental ramp protocol on a cycle ergometer (Bosch 550 ERG) to establish V02 MAX, T VENT and delta efficiency. Breath-by-breath respiratory gas analysis was undertaken using a respiratory mass spectrometer (MGA1100). Estimates of alveolar gas exchange were made using the algorithm of Beaver et al. (1981) and a post hoc value of an effective lung volume was calculated to minimise the breath-by-breath variability. A cross-correlation technique (CC) was used to filter out the effects of anomalous (nonphysiologic) V02 responses recorded during the PRBS protocol. Subsequent Fourier analysis of the auto-correlation and CC functions provided a description of V02 KINETICS in the frequency domain in terms of amplitude ratio and phase delay over the frequency range of 2.2-8.9mHz. At each of the frequencies assessed amplitude ratio was higher in children (P<0.001) than in either of the adult groups. Phase delay was also significantly shorter in children compared to adults males (P<0.01) and adult females (P<0.001) but this effect was not identifiable at any specific frequency. Maximal oxygen uptake was not significantly different in adult males (42.5 ml"kg "min) and children (44.7 ml-kg'-min') but was lower in adult females (36.9 ml"kg "min) than adult males (P<0.01) and children (P<0.001). Ventilatory threshold (% V02 MAX) was not different between groups. Delta efficiency was significantly lower in children than adult males (P<0.05) and adult females (P<0.01). These results support the contention that there are maturational differences between adults and children in the metabolic processes involved in the utilisation of oxygen during physical activity. It has been argued, theoretically, that in adults the control of V02 KINETICS is driven by ATP demand in the skeletal muscle. As the mitochondria] capacity and the concentration of oxidative enzymes is higher in children than in adults it is likely that the controlling factor(s) for V02 KINETICS in children also relates to some aspect of peripheral metabolism. It is suggested that the PRBS protocol, with appropriate noise reduction techniques, is considered a suitable method for investigating the metabolic responses of children to dynamic exercise.

This thesis set out to answer 4 major questions: 1) Do elite hockey players arrive for a game hydrated and do they consume enough fluid to prevent dehydration over the course of a game? 2) Is hydration status repeatable between days and can an athlete who arrives dehydrated prior to training or competition become hydrated in the time before the start of activity? 3) What is the extent of dehydration (%body mass (BM) loss) necessary to change substrate oxidation and skeletal muscle metabolism during exercise in male and female subjects? 4) Will progressive dehydration have a negative effect on endurance performance? The first study evaluated the pre-game hydration status, sweat loss and fluid intake patterns of elite male junior ice hockey players during a game. Sweat loss was 3.2 ± 0.2L and exceeded net fluid intake (2.1 ± 0.1L). Mean BM loss was 1.3 ± 0.3%, but 8 out of 24 players lost between 1.8 - 4.3% BM. Despite abundant opportunities to hydrate during a hockey game, 33% of players did not drink enough to prevent sweat losses of ≥2% BM. The second study investigated 1) the day-to-day variability of morning urine specific gravity (USG) and consuming 600mL of water on the hydration status of hydrated and dehydrated (USG>1.020) subjects, and 2) the effects of consuming water or carbohydrate electrolyte solutions (CES) on hydration status of dehydrated subjects. Morning USG and hydration responses to the ingestion of 600mL of water were repeatable and mildly dehydrated subjects could reach euhydration within 45min after ingesting any type of fluid with no added effect of a CES. The next two studies (3 & 4) investigated the effects of mild progressive dehydration during 120min of exercise at ~65% VO2peak on whole body substrate oxidation and skeletal muscle metabolism, as well as cardiovascular, thermal, and mental responses in recreationally active, hydrated females and males. In both studies, muscle glycogenolysis was increased in the initial 60min of exercise in the dehydrated state when BM loss were ≤1%. Increased glycogenolysis appeared due to increases in core temperature during progressive dehydration as there were no differences in plasma epinephrine or the energy status of the cell (free ADP or AMP) between trials. Normal changes in physiological parameters accompanying exercise in a hydrated state were exacerbated with progressive mild dehydration. The final study determined the impact of dehydration on cycling performance. Active males cycled at ~65% VO2peak for 90min followed by a time trial (TT: 6 kJ/kg BM) with fluid to replace sweat losses (HYD) or without fluid (DEH). DEH subjects began the 90 min trial 0.6% dehydrated and progressively became more dehydrated with a BM loss of 1.4% at 45min, 2.3% at 90min, and 3.1% post-TT. TT performance was significantly compromised with ~2-3% BM loss (HYD 32 ± 4 vs. DEH 36 ± 3 min).

The aim of this thesis was to investigate how physiological and environmental factors affect surfing performance. Studies were performed that assessed the effect of anthropometric and physiological characteristics of surfers on rank and ability, the effect of creatine supplementation on surfing performance and the effect of wave size, wave period and the ability of surfers on physiological and performance indices of surfing. Study one investigated the effect of the anthropometric variables on rank and rating of ability. This was measured across a sample of 79 surfers ranging from intermediate to professional surfers. Significant correlations were found for endomorphy (r = -0.366, P <0.01), sum of six skinfolds (r = -0.274, P <0.05), Body fat percentage (r = -0.268, P <0.01) and mesomorphy (r = 0.442, P <0.01). Findings suggest that levels of adiposity and muscularity might influence the potential for progression between intermediate and professional level surfing performance. Study two investigated the effect of physiological variables on the national ranking of 18 elite male junior surfers using assessments of maximal oxygen uptake, lower body explosive power, upper body power, agility, and balance. Partial correlations were used to account for the influence of age within the sample and a significant correlation was found between power output at (rp = -0.879, P <0.01). Findings suggest that power output at is an important factor for achieving competitive success in high performance junior surfers. Study three investigated the effect of short term (20g.day-1 for 5 days) creatine supplementation on body composition, repeated upper body anaerobic power and competition performance was assessed in 17 club level surfers. Testing comprised assessment of body mass and total body water using bioelectrical impedance analysis, a repeated upper body Wingate based on time motion analysis of competitive surfing. A two-way repeated measures ANOVA found no significant effects of supplementation on laboratory measures of anaerobic power or competitive performance. The fourth study investigated the effects of changes in wave conditions on physiological response and performance parameters of surfing. This was assessed using 39 surfers who participated in 60 surfing sessions where wave conditions were recorded and performance was measured using GPS. The study found that wave height was significantly related to energy expenditure (rp =-0.351, P <0.05), maximum ride speed (rp = 0.866, P <0.01), the standard deviation of maximum ride speeds (rp = 0.654, P <0.01), mean ride time (rp = 0.354, P <0.01), maximum ride time (rp = -0.296, P <0.05), the standard deviation of the ride times expenditure (rp = -0.344, P <0.01), mean ride distance (rp = 0.398, P <0.01), maximum ride time (rp = 0.318, P <0.05), minimum ride distance (rp = 0.268, P <0.05), standard deviation of the ride distances (rp = -0.362, P <0.01), percentage of total distance riding (rp = 0.310, P <0.05), percentage of time spent waiting (rp = -0.272, P = 0.05), percentage of total time spent riding (rp = 0.396, P < 0.01), percentage of total time in miscellaneous activities (rp = 0.471, P <0.01), total distance riding (rp = 0.310, P =0.05), total distance per hour (rp = 0.427, P <0.01). Wave period was found to be significantly related to average heart rate as a percentage of maximum (rp = 0.490, P <0.01), the percentage of time spent in the “easy” training zone (rp = -0.408, P <0.01), maximum ride speed (rp = 0.371, P <0.01), mean ride time (rp = 0.283, P <0.05), maximum ride distance (rp = 0.279, P <0.05), and the standard deviation of the ride distances (rp = 0.325, P <0.05). The ability levels of the surfers were found to be significantly related to average heart rate as a percentage of maximum (rp = -0.412, P <0.01), percentage of time in the “steady” zone (rp = 0.435, P <0.01), percentage of time in the “intermittent” zone (rp = 0.483, P <0.01), maximum ride speed (rp = 0.454, P <0.01), mean ride distance (rp = 0.392, P <0.05), standard deviation of the ride distances (rp = 0.264, P <0.05), percentage of the total distance riding(rp = 0.267, P <0.05), percentage of time paddling (rp = 0.364, P <0.05), percentage of time in miscellaneous activities (rp = -0.299, P <0.05), total distance riding (rp = 0.267, P <0.05) and average speed (rp = 0.428, P <0.01). This thesis has found that ability in surfing is related to anthropometric and physiological measures, creatine supplementation improves peak anaerobic power but does not significantly improve surfing performance in club level surfers and that wave conditions and the skill levels of surfers are significantly related to the physiological and performance parameters of surfing.

Diss. (sammanfattning) Umeå : Umeå universitet, 2006. / Härtill 4 uppsatser.

The following thesis investigates contemporary issues within the applied physiology of soccer refereeing. 1) Training performance. The impact of a high intensity training regime was examined in a group of elite-level soccer referees. Following a 16-month training period the referees’ performance on the YoYo Intermittent Recovery Test (level 1) improved by 46.5%. 2) Match Demands. The effect of match standard and referee experience upon the objective and subjective match loads of referees was investigated. Match heart rates (HR) and ratings of perceived exertion (RPE) were both related to standard of competition, with the match loads being higher on the higher standard of competition. Referee experience had no effect upon the referees’ match responses. Using a semi-automatic, video match analysis system the referees’ match activities and factors affecting these activities were also examined. Physical performances were related in part to the physical performances of the players; whilst the distances covered during the first half were related to second half coverage. 3) Ageing and performance. The effect of ageing upon referees’ fitness levels and physical match performances was addressed. Regression analysis revealed a trend towards an agerelated reduction in physical fitness, as determined by the referees’ fitness tests. Match activity analysis demonstrated a clear age-related decline in physical match performance, although this decline did not impair the referees’ ability to keep up with play. 4) Fitness and match performance. The validity of the FIFA referees’ fitness tests was examined. Interval test HR load was significantly correlated to the referees’ match coverage, both total distance and high intensity running. Sprint test scores also demonstrated a significant relationship with the referees’ match sprinting distances. However, given the strength of the relationships only the sprint test showed appropriate construct validity for the physical assessment of soccer referees.

Syfte och frågeställningar: Syftet med denna studie var att belysa hur serbiska och svenska landslagstränare planerar en säsong i 3x3 basket. Förhoppningsvis kommer uppfattningen förbättras om vad som kan påverka och vilka delar som är viktiga i träningsuppläggen. Anledningen till att Serbien undersöks är på grund av att de är en världsledande nation inom 3x3 basket och att deras träningsupplägg kan vara en anledning till deras framgång. Studien strävar efter att svara på följande frågeställningar: ●  Vad är orsaken till framgångarna för det serbiska 3x3 landslaget? ●  Vad anser 3x3 landslagstränarna i Serbien och Sverige är viktiga delar i träningsupplägget under en säsong, med fokus på aeroba och anaeroba förmågor? ●  Vilka orsaker upplever tränarna i Serbien och Sverige påverkar träningsupplägget? Metod: Syfte och frågeställningarna besvarades med hjälp av en kvalitativ intervjustudie. Den kvalitativa datainsamlingen har sammanställts och bearbetats genom meningskoncentreringsmodellen i programmet NVivo-version 12. Resultat: Studien påvisar att Serbien och Sverige har två olika tillvägagångsätt när det kommer till planeringen och utförandet av sina träningsupplägg. Analys av data ledde oss till en huvudorsak som visades påverka hur utformningen av ett träningsupplägg för de aeroba och anaeroba förmågorna kan komma att se ut. Huvudorsaken påvisar att träningsupplägget ser annorlunda ut eftersom serbiska herrlandslaget enbart spelar 3x3 basket. Utifrån huvudorsaken förekom också att träningsupplägget utformas beroende på tiden som tränarna har att spendera med laget och antal turneringar som spelas under en säsong. En annan orsak som påverkar träningsupplägget är tränarnas individuella erfarenheter och tillgångar. Slutsats: Studiens slutsats är att det svenska träningsupplägget kan förbättras och att Serbien ständigt försöker utveckla sitt redan framgångsrika träningsupplägg. Det svenska träningsupplägget för utveckling av aeroba och anaeroba förmågor behöver planeras och struktureras för att spelarna ska uppnå bättre form. Slutsatsen är att rekrytering av spelare som enbart ska spela 3x3 basket skulle bidra till bättre resultat för både de serbiska damerna och hela svenska landslaget. Utformandet av sportens kravprofil i Sverige skulle kunna leda till bättre planering av när och hur landslaget bör samlas och börja träna. / <p>Ämneslärarprogrammet, Specialidrott.</p>