Despite similar rates of energy expenditure during training, competitive swimmers have been shown to store significantly greater amounts of body fat than competitive runners. In an attempt to explain these discrepancies, male collegiate swimmers (n=8) and runners (n=8) were monitored during 45 min of swimming and running, respectively (75% V02 max), and during two hours of recovery. In addition, a group of male competitive triathletes (n=6) were similarly monitored during and after both swimming and running exercise.Blood samples were obtained after 15 min rest prior to exercise and at 0, 15, 30, 60 and 120 min of recovery and were analyzed for glucose, lactate, glycerol, free fatty acids, insulin, glucagons, norepinephrine (NE) and epinephrine (E). Respiratory gases were collected at 15 min intervals during exercise and at 15, 30, 45, 60, 90 and 120 min of recovery. Heart rate and mean body temperature were recorded at 10 min intervals throughout recovery. There were no differences in post-exercise oxygen consumption or heart rate while the RER suggested increased fat oxidation after exercise for the swimmers and the swimming triathletes. The mean body temperature and mean skin temperatures were significantly lower throughout 120 min of recovery for the swimmers compared to the runners. The triathletes demonstrated a similar tendency but these differences were not significant. The serum glucose levels were significantly greater (P<0.05) immediately post-exercise for the runners compared to the swimmers (6.71 +0.29 and 4.97 +0.19 mmol•1-1, respectively). Blood glucose values were also significantly greater immediately post-run for the triathletes (6.40 +0.26 and 4.87 ±0.18 mmol-l-1 for running and swimming, respectively). Blood glucose values remained elevated for runners and the running triathletes up to 30 min of recovery. Free fatty acids were similar after the run and the swim, but glycerols were increased immediately after running in the runners (P<0.05) and the triathletes (P<0.05). Differences in blood glucose levels or fat release were not explained by differences in NE, E or cortisol. The glucagon-to-insulin (G:I) ratio was significantly increased after exercise in the swimmers and the swimming triathletes. This, combined with a reduced RER after the swimming trials, suggests that the reduced glucose levels were due to reduced hepatic glycogen stores. The results of this study suggest that there were differences in substrate utilization during running and swimming exercise of the same intensity. These differences were not explained by NE, E or cortisol; however, the increased G:T ratio suggests increased carbohydrate use during exercise in the swimmers. Finally, body fat differences between runners and swimmers were not explained by differences in post-exercise energy expenditure or fat oxidation.

The purpose of this study was to profile international level female sevens athletes and determine if anthropometric and physical qualities are able to differentiate between backs and forwards. Twenty-four subjects with a mean (±SD) age of 22.75±3.99 years and body weight of 69.36±5.21kg were sampled from the national team training program. Anthropometric measures (height, body mass and sum of 7 skinfolds) and performance measures (power clean, front squat, bench press, neutral grip pull up, 40m sprint and 1600m run) were collected across the 2013-2014 centralized period and compared across playing position. Thirteen backs (mean age±SD= 21.28±3.54 years) and eleven forwards (mean age±SD= 24.47±3.95 years) had significant differences in body mass (66.40±3.48kg vs. 72.87±4.79kg) and initial sprint momentum (366.81±19.83kg*m/s vs.399.24±22.42*m/s). However no other measures showed positional differences. It is possible that the lack of positional differences in female rugby sevens is due to the multifarious physical requirements of a sevens player, leading to a generic player profile or perhaps due to a lack of selective pressure. It is also possible that the anthropometric and physical qualities measured in this study lacked the necessary resolution or failed to capture the unique attributes of each position. In conclusion, this is the first research profiling international level female sevens athletes. The normative data presented within this paper highlights the physical requirements of female sevens athletes for strength and conditioning practitioners. In addition, the lack of positional differences discovered should impact training program design. / Graduate

No description available.

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.

Ten trained male track athletes (VO2max = 64.7 ml&middot;kg&middot;min -1) performed three workouts (conditions) with repeated 400-m runs. The intensity and number of repetitions varied among conditions. Condition 1 consisted of two all-out 400-m runs. Condition 2 was 4 x 400-m runs with the first three reps performed 4 s slower than condition 1 and the 4 th rep was all-out. Condition 3 consisted of 8 x 400-m runs with the first seven reps performed 8 s slower than condition 1 and the 8th rep was all-out. Dependent variables were HR, blood lactate and run time for the final rep in each condition. Peak HRs for the last run were 201, 194, 189 beats&middot;min-1 for conditions 1, 2 & 3 respectively, and were not significantly different. Blood lactate values measured 4 min after the last run were 16.6, 17.8 and 17.1 mmol&middot;L -1 in conditions 1, 2 and 3 respectively, and were not significantly different. Run times for conditions 1 (55.2 s), 2 (56.9 s) and 3 (61.5 s) were significantly different (P < 0.05). The decline in performance was greatest in condition 3. The three conditions challenged the anaerobic system with similar peak values for lactate and heart rate during the final run.

Thesis (M.S.)--University of Hawaii at Manoa, 2006. / Includes bibliographical references (leaves 37-41). / viii, 52 leaves, bound ill. 29 cm

Thesis (M.S.)--University of Texas at El Paso, 2007. / Title from title screen. Vita. CD-ROM. Includes bibliographical references. Also available online.

Thesis (M.A.)--Ohio University, November, 2007. / Title from PDF t.p. Includes bibliographical references.

Thesis (M.S.)--Oregon State University, 2009. / Printout. Includes bibliographical references (leaves 20-24). Also available on the World Wide Web.

Thesis (M.S.)--Eastern Illinois University, 2008. / Includes bibliographical references (leaves 35-40).