The purpose of this thesis was to study the effects of a pre-exercise carbohydrate meal on metabolism, endurance capacity and performance during prolonged running when carbohydrate was, or was not consumed during exercise. The first study (Chapter 4) examined the effects on endurance running capacity of ingesting a carbohydrate-electrolyte solution during treadmill exercise to fatigue at 70% V02 max after subjects (10 males) had undergone an overnight fast (P+C), or when fed with a 2.5 g. kg-1 BW carbohydrate meal 3 hours before exercise (M+C). Exercise time to exhaustion was longer in the M+C (147.4 ± 9.6 min) and P+C (125.1 ± 7.0 min) trials compared with the control condition (P+P: 115.1 ± 17.6 min) (p< 0.01 and p< 0.05 respectively). Also, exercise time was longer in the M+C compared with the P+C trial (p< 0.01). The improvement in endurance capacity in the M+C trial occurred despite a higher carbohydrate oxidation rate during the first hour of exercise. The second study (Chapter 5) examined whether a pre-exercise carbohydrate meal (M+W) can improve endurance capacity, and further examined if the combination of a pre-exercise meal together with the ingestion of a carbohydrate-electrolyte solution during exercise (M+C) would be superior to the carbohydrate meal (M+W) alone. Ten males volunteered in this study. Although the consumption of the meal increased carbohydrate oxidation during the first hour of exercise, exercise time to fatigue at 70% V02 max was longer in the M+C (125.1 + 5.3 min) and M+W (111.9 + 5.6 min) trials compared with the control trial (P+W : 102.9 ± 7.9 min) (p< 0.01 and p< 0.05 respectively). Also, exercise time was longer (p< 0.05) in the M+C compared with the M+W trial. The third study (Chapter 6) investigated whether the high carbohydrate meal can influence muscle glycogen levels. Eight male subjects participated in the study. Three hours after the ingestion of the 2.5 g. kg-1 BW carbohydrate meal, muscle glycogen concentration was 10.6% higher (p< 0.05) in the vastus lateralis muscle (347.3 + 31.3 mmol. kg dw-1) compared with the muscle glycogen concentration before feeding (314 ± 33.9 mmol. kg dw-1). The fourth study (Chapter 7) examined the influence of ingesting a carbohydrate-electrolyte drink (M+C) on the muscle glycogen utilisation during 60 min running at 70% V02 max in subjects (8 males) who had consumed a carbohydrate meal 3 hours before exercise (M+W). Muscle glycogen concentrations were not different before (M+C : 321.9 ± 27.2 vs M+W : 338.8 ± 32.8 mmol. kg dw-1), as well as after exercise (M+C : 225.8 ± 26.7 vs M+W: 261 + 40.5 mmol. kg dw-1) between the two experimental trials. Neither was there any difference in the rate of muscle glycogen utilisation (M+C : 96.1 ± 22.1 vs M+W: 77.9 ± 11.7 mmol. kg dwl. h-1). The aim of the last study (Chapter 8) was to investigate whether, after an overnight fast, the ingestion of a carbohydrate-electrolyte solution during a 30 km self-paced treadmill run (C) would be as effective as the consumption of a carbohydrate meal (M) (2.0 g. kg-1 BW carbohydrate) 4 hours before exercise. Ten males volunteered for this study. The overall performance times in the M and C trials were identical (M: 121.8 ± 3.6 min vs C: 121.7 ± 4.1 min). No differences were found between the two trials in running speeds over each successive 5 km, or even when running speed was analysed every kilometre. Also, no reduction in the self-selected speeds of subjects was observed towards the end of the 30 km run in both conditions. The ingestion of a carbohydrate meal, providing 2.5 g. kg-1 BW carbohydrate, 3 hours before exercise increases muscle glycogen concentration and improves endurance running capacity, despite an elevated carbohydrate oxidation rate during the first hour of exercise. It seems that the amount of carbohydrate given before exercise compensates for the greater carbohydrate used. Furthermore, the combination of both a pre-exercise carbohydrate meal and a carbohydrate-electrolyte solution ingested during exercise further improves endurance capacity.

The purpose of this study was to compare the efficacy of two dose levels of L-Alanyl-LGlutamine in a commercially available sports drink to the sports drink only on time to exhaustion, neuromuscular fatigue and physiological measures during prolonged endurance exercise. Twelve endurance-trained males (23.5±3.7 yrs; 175.5±5.4 cm; 70.7±7.6 kg) performed four trials, each consisting of 1 hr treadmill runs at 75% of VO2peak followed by a run to exhaustion at 90% of VO2peak. The trials differed in type of hydration. One trial consisted of no hydration (NHY), another required ingestion of only a sports drink (ET), and two trials required ingestion of a low dose (LD) (300 mg∙500 ml-1) and high dose (HD) of L-Alanyl-L-Glutamine (1 g∙500 ml-1) mixed in the sports drink. During the fluid ingestion trials 250 ml were consumed every 15 min. Plasma glutamine, glucose, electrolytes, and osmolality were measured prior to the run (PRE), and at 30, 45, and 60 min. VO2, RQ, and HR were measured every 15 min and surface electromyography (EMG) of the vastus lateralis and rectus femoris were measured every 10 min during the 1 hr run. Time to exhaustion was significantly longer during the LD and HD trials compared with NHY. Plasma glutamine concentrations were significantly elevated at 45 min in LD and HD trials, and remained elevated at 60 min during HD. Sodium concentrations increased with the beginning of exercise and remained stable for the duration of the 1 hr run. At 60 min plasma sodium was significantly lower in all trials compared with NHY. The results from this study indicated that ingestion of the alanine-glutamine dipeptide at either the low or high dose significantly improved time to exhaustion during high intensity exercise compared to a no hydration trial. These differences were not noted between ET and NHY.

Title: Obstacle course racing: the effect of obstacles on the total race time during a Spartan Race Objectives: The aim of this study was to determine the effect of 30-burpee punishment on subsequent running speed (SPD), heart rate (HR) following a missed obstacle, and the final race standings during a OCR race. Methods: In our thesis we used a method of analysis in an official Spartan Race in the Czech Republic. 11 male OCR competitors wore a GPS and HR monitor, from which HR and SPD were measured. Three specific obstacles were chosen where nearly all competitors did burpees (spear throw), half did burpees (traverse wall), and nearly none did burpees (monkey bars). The HR and SPD were measured during the entire race, and specifically noted when the competitors arrived at left the obstacle. Results: The average HR of the entire race was 166.45 ± 3.34 beats per minute. The average time spent at the successful obstacles without burpees was 23 ± 17 seconds, while the average time spent at the unsuccessful obstacles with burpees was 124 ± 11 seconds. The change in HR over the course of successful obstacles was 0.79 ± 3.69 beat per minute, while the change in HR during unsuccessful obstacles with burpees was -3.00 ± 6.70 beat per minute. Total time spent at each obstacle correlated with the final...

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ABSTRACT Male subjects are invariably used to study the physiological determinants of middle distance running performance. Studies that do include females have examined only the aerobic contribution to middle distance running performance. The aim of the present study was to investigate aerobic, anaerobic and muscle function factors that could be used to predict middle distance running performance in female runners. This study was performed at an altitude of 1800m. Eleven middle distance female runners aged 18-20 were selected for the study. Aerobic capacity was assessed by measuring the maximal oxygen consumption (VO2max), running velocity at maximal oxygen consumption (vVO2max), running economy (RE) and onset of blood lactate accumulation (OBLA). The blood lactate curve of each subject was constructed by relating the oxygen consumption, to the plasma lactate concentrations. Anaerobic capacity was determined by measuring the maximum accumulated oxygen deficit (MAOD) on a treadmill. Muscle function was assessed by having the subjects cycle as fast as possible against changing brake weights ranging from heavy to light using a Monark cycle ergometer. The brake force (kg) was related to velocity (rpm).

Purpose: The aims of these studies were to examine the effects of wearing different grades of graduated compression stockings (GCS) on performance, physiological, and perceptual measures before, during, and after exercise in well-trained runners. Method: Two separate running studies were conducted where participants wore different grades of GCS compared with a placebo control stocking in random, counter-balanced order: (1) a field study focussed on a series of 10-km running performances on a 400m track; (2) a laboratory study that examined the effects of 40-min treadmill running on physiological, perceptual, and muscle function responses. Changes in muscle function and damage were determined pre- and post-run by measuring creatine kinase (CK) and myoglobin (Mb) concentrations, counter-movement jump (CMJ) height, muscle soreness, and pressure sensitivity. Physiological measurements of heart rate (HR), oxygen uptake (V&O2), blood lactate concentration [La], and ratings of perceived exertion (RPE) were measured during running. Pre- and post-run perceptual scales assessed comfort, tightness and pain associated with wearing GCS. Results: There were no significant differences in 10-km run time, mean HR, V&O2, [La], and RPE for participants wearing different GCS in (1) and (2) (P<0.05). Con and Low were rated most comfortable (P<0.05) and Hi were tightest (P<0.05) and induced more pain (P<0.05) when GCS were compared in both studies. CMJ was better in participants wearing Low and Med GCS post-run compared with Con in (1) and for Con and all GCS at 0 h post-exercise in (2). CK and Mb levels were higher (P<0.05) and pressure sensitivity was more pronounced (P<0.05) at 0 h post-run for Con and all GCS (2). Few participants (4/10) reported muscle soreness at any one location in (2). Conclusions: Well-trained runners did not experience improved performance, physiological, or perceptual responses when wearing different grades of GCS during 10- km track or 40 min treadmill running compared with a control garment. 40 min treadmill running at 80% V&O2 max may not be strenuous enough to elicit a loss of muscle function in well-trained runners. Runners felt more comfortable wearing GCS that had less compression.