High-density lipoprotein (HDL) with its cardio- protective effects has provided remarkable optimism to the ever-increasing incidences of coronary artery disease. Therefore, the aim of this randomized, comparative, research trial was to determine whether endurance exercise training, weight training and/or a combination of aerobic and weight training can be utilized in the management of high-density lipoprotein cholesterol (HDL-C). Subsequent to the 16-week intervention period, dependant t-Tests revealed that the non-exercising and weight training groups demonstrated non- significant mean 1.3% (p = 0.754) and 11.1% (p = 0.069) increases in fasting serum HDL-C, respectively. Conversely, there was a significant increase in HDL-C following the 16 weeks of endurance training (p = 0.003) and combination training (p = 0.005) (22.4% and 37.9%, respectively). Further, Spearman’s rho indicated no correlations between HDL-C and BMI (r = -0.131), percentage body fat (r = - 0.141), cholesterol intake (r = - 0.026) and total fat intake (r = - 0.239). The absence of changes in these inter-correlations indicated that changes in these parameters had no effect on the HDL-C. On the contrary, moderate correlations were established between HDL-C and number of cigarettes smoked daily (r = - 0.344) and intake of saturated fat (r = - 0.317) indicating that exercise effect on these variables could have indirectly contributed significantly in altering HDL- C in the endurance and combination training groups. As such, endurance and combination training can be utilized as an effective method in the management of HDL-C in sedentary male smokers.

The metabolic heat generated by exercise must be dissipated to maintain body temperature within narrow physiological limits; during exercise and heat exposure, body water is lost via sweating to enable evaporative cooling of the body. When sweating takes place, total body water is reduced (without the intake of additional fluids) from each fluid compartment due to the free exchange of water between compartments with a concomitant loss of electrolytes, primarily sodium. A series of three investigations were undertaken to evaluate: 1) the efficacy of acute sodium citrate-chloride loading on endurance trained males and females as a viable means to expand extracellular fluid volume, 2) any menstrual cycle effects on renal handling of this sodium load at rest, and 3) if any subsequent hypervolaemia reduces the physiological strain of exercise in warm conditions in both genders. The first investigation examined eight endurance-trained (VO₂[max]: 58 ml�kg⁻��min⁻� (SD 5); 36 y (SD 11)) runners in a randomized double-blind crossover study. The participants ingested a high-sodium (HighNa⁺: 164 mmol Na⁺�L⁻�) or low-sodium (LowNa⁺: 10 mmol Na⁺�L⁻�) beverage (10 ml�kg⁻�) before running to exhaustion at 70% VO₂[max] in warm conditions (32�C, 50% RH, V[a]~1.5 m�s⁻�). Results indicate that HighNa⁺ increased PV before exercise (4.5% (SD 3.7)), calculated from Hct and [Hb]), whereas LowNa⁺ didn�t (0.0% (SD 0.5); P = 0.04), and involved greater time to exercise termination in those who were stopped due to ethical end point of 39.5�C and volitional exhaustion (39.5�C: 57.9 min (SD 6) vs. 46.4 min (SD 4); n = 5, P = 0.04; EXH: 96.1 min (SD 22) vs. 75.3 min (SD 21); n = 3, P = 0.03; HighNa⁺ vs. LowNa⁺ respectively). At equivalent times before exercise termination, HighNa⁺ also involved lower core temperature (38.9 vs. 39.3�C; P = 0.00) and perceived exertion (P = 0.01), and a tendency for lower heart rate (164 vs. 174 bpm; P = 0.08). The main purpose of the second investigation was to investigate the efficacy of an acute sodium load on endurance trained women�s plasma volume and renal mechanisms across the menstrual cycle at rest. This was evaluated by inducing a sodium-mediated plasma volume expansion using HighNa⁺ at rest during the last high hormone week of the OCP cycle (HH[ocp]) or the late-luteal phase of the natural cycle (LUT[nat]) and during the low hormone sugar pill week of the OCP cycle (SUG[ocp]) or during the early follicular phase of the natural cycle (FOL[nat]. Thirteen women completed the study with one woman on a progestin-only pill (results were used for case study, not statistical analyses) and were assigned to one of two groups: 1) control (NAT, n = 6, 24 y (SD 5), 53 ml�kg�ml⁻� (SD 3)) or oral contraceptive pill (OCP, n = 6, progestin only n = 1, 29 y (SD 6), 51 ml�kg�ml⁻� (SD 2)) group according to their usage status. Across the four-hour post loading time there was greater plasma volume expansion in SUG[ocp] and FOL[nat] vs. LUT[nat] and HH[ocp] (5.06% (SD1.16) vs. 3.35% (SD 0.23), P = 0.02). OCP usage did not reliably alter the hypervolaemic response (P = 0.27), and this was not dependent on phase of cycle (P = 0.32). Plasma volume expansion occurred across both types and phases of the menstrual cycle with evidence that estradiol interactions with AVP, P[osm] and body water retention are stronger in the low hormone phase of the OCP than in the follicular phase of the natural cycle; illustrated by greater overall water retention after an acute sodium+water load. The third investigation was conducted during the high hormone phase of both OCP and NAT menstrual cycles to further examine sodium-loading effects on the physiological capacity of exhaustive cycling in warm conditions. Thirteen endurance-trained (VO₂[peak] 52 ml�kg⁻��min⁻� (SD 2); 26 y (SD 6), 60.8 kg (SD 5), mean (SD)) cyclists completed this double-blind, crossover experiment during the high hormone phase of the menstrual cycle. Cyclists ingested a concentrated sodium (HighNa⁺: 164 mmol Na⁺�L⁻�) or low-sodium (LowNa⁺: 10 mmol Na⁺�L⁻�) beverage (10 ml�kg⁻�) before cycling to exhaustion at 70% VO₂[max] in warm conditions (32�C, 50% RH, V[a]~5.6 m�s⁻�). HighNa⁺ increased PV before exercise, similar to that of the men in the first investigation, whereas LowNa⁺ didn�t (4.4% (SD 1.2) vs. -1.9% (SD 1.3); P < 0.0001), and involved greater time to exhaustion (98.6 min (SD 25.6) vs. 78.5 min (SD 24.6); P < 0.0001). There was a higher baseline core temperature and faster rate of change for HH[ocp] for both beverage conditions (HighNa⁺: 37.15 (SD 0.6) vs. 36.92�C (SD 0.4); P = 0.05, LowNa⁺: 37.04 (SD 0.6) vs. 36.90�C (SD 0.4), P = 0.05; HH[ocp] vs. LUT[nat], respectively). Through this series of investigations a greater understanding was achieved of fluid balance and the effect of pre-exercise hypervolaemia between genders; pre-exercise ingestion of a concentrated sodium beverage increased plasma volume before exercise and involved less thermoregulatory and the actual and perceived physiological strain during exercise and increased endurance in warm conditions.

Thesis (D. Phil.(Biokinetics, Sport and Leisure Sciences))--University of Pretoria, 2007. / Summary in English and Afrikaans. Includes bibliographical references.

Thesis (Ph. D.)--Victoria University of Technology, 2005. / Includes bibliographical references.

Thesis (Ph. D.)--University of Hawaii at Manoa, 2003. / Includes bibliographical references (leaves 163-177).

Thesis (MHSc--Health Science) -- AUT University, 2007. / Includes bibliographical references. Also held in print (x, 133 leaves : ill. ; 30 cm.) in North Shore Campus Theses Collection (T 612.22 VIC)

Thesis (M.S.)--Brigham Young University. Dept. of Physiology and Developmental Biology, 2007. / Includes bibliographical references (p. 46-54).

Thesis (M.A.)--University of North Carolina at Chapel Hill, 2004. / Includes bibliographical references (leaves 76-79). Also available online (PDF file) by a subscription to the set or by purchasing the individual file.

Thesis (M.Sc.)--York University, 2003. Graduate Programme in Kinesiology and Health Science. / Typescript. Includes bibliographical references (leaves 113-122). Also available on the Internet. MODE OF ACCESS via web browser by entering the following URL: http://wwwlib.umi.com/cr/yorku/fullcit?pMQ99371

Thesis (M.S.)--Purdue University, 2003. / Includes bibliographical references (leaves 41-49).