Massey Documents by Type

Permanent URI for this communityhttps://mro.massey.ac.nz/handle/10179/294

Browse

Subject: search.filters.subject.Athlete nutrition

Search Results

Now showing 1 - 3 of 3
  • Thumbnail Image
    Item
    A measure of dietary protein requirement in endurance trained women : a thesis submitted in the partial fulfilment of the requirements for the degree of Master of Science in Sport and Exercise Science, Massey University, (Wellington, New Zealand)
    (Massey University, 2011) Houltham, Stuart Douglas
    Purpose: Inference from dietary surveys and experimental models suggest that the female endurance athlete dietary protein requirement is 15-20% less than their male counterparts, but to date empirical measurement of the habitual protein requirement has not been undertaken. Methods: 72-h nitrogen balance (NBAL) was determined in 10 female cyclists training 10.8 h·w-1 (SD: 2.82), following two habituated protein intakes: a) a diet representing normal habitual intake (NH) (Protein: 85g.d-1 Energy: 9078kJ·d-1), b) an isolcaloric high-protein diet (HP) (Protein: 166g·d-1, Energy: 8909kJ·d-1). Total 72-h nitrogen intake was determined from Leco total combustion analysis from samples of the ingested food items, while total loss was determined from micro-kjeldahl analysis of total 72-h urine, urea nitrogen concentration of regional resting and exercise sweat sampling, and literature-based estimates of fecal and miscellaneous nitrogen losses. Habituated protein requirement was estimated by the mean regression of the two estimates of 72-h nitrogen balance vs. nitrogen intake. Results: Mean (SD) 24-h dietary protein intake during the 72-h sampling period was NH: 85 (11g), HP: 166 (19g). Mean 24-h urinary nitrogen during the NH and HP blocks were 13.19 (2.39 g·d-1) and 21.53 (3.94 g·d-1) respectively. Sweat urea nitrogen excretion was NH: 0.33 (0.08 g·d-1) and HP: 0.54 (0.12 g·d-1). Normal habitual and high-protein intakes resulted in a mean negative and positive nitrogen balance, respectively (mean ± SD) (NH: -0.59 ± 1.64, HP: 2.69 ± 3.09). Estimated mean protein requirement to achieve NBAL was calculated to be 1.63 g·kg-1·d-1 (95% confidence interval: 1.14–3.77). Conclusions: Our data shows that the dietary protein requirement for well-trained females taking part in daily moderate intensity and duration endurance training is within the range of measured requirement for similarly trained men and suggests that the current estimated range of protein requirement for females may be inadequate.
  • Thumbnail Image
    Item
    Effect of leucine-protein high-carbohydrate post-exercise nutrition on subsequent performance and the protein regulated genomic and signalling events governing adaptive remodelling : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Nutritional Science, Massey University, Albany, New Zealand
    (Massey University, 2010) Thomson, Jasmine Sarah; Thomson, Jasmine Sarah
    Recovery from prolonged endurance exercise requires fuel replenishment and ultrastructure repair to restore cellular homeostasis; and improvement requires adaptive remodelling. Timing nutrient intake to closely follow exercise may be advantageous to recovery and subsequent performance by facilitating the adaptive processes stimulated by exercise. The objective of this research was to firstly determine if leucine-enriched protein feeding after hard training improved subsequent performance, and secondly to explore the candidate means by which protein-rich post-exercise nutrition mediates recovery, primarily transcriptomic and signalling mechanisms. Study 1 Ten male cyclists ingested leucine-enriched protein-carbohydrate (0.1/0.4/1.2/0.2 g∙kg-1∙h-1 leucine/protein/carbohydrate/fat) or isocaloric high-carbohydrate control (0.06/1.6/0.2 g∙kg-1∙h-1) meals following 2-2.5 h high-intensity interval training on 3 consecutive days. Cyclists performed a repeat-sprint performance test 39 h after training, and markers of physiological recovery and mood state were examined. Study 2 Eight male cyclists ingested protein (0.4/1.2/0.2 g∙kg-1∙h-1 protein/carbohydrate/fat) or isocaloric high-carbohydrate control (0.03/1.6/0.2 g∙kg-1∙h-1) beverages following a single 1.75 h high-intensity interval cycling bout. Muscle tissue samples were collected from the vastus lateralis before exercise, 3-h and 48-h post-exercise. The transcriptome response was assessed by Illumina microarray, candidate gene expression by real time RT-PCR; and phospho-protein signalling by Western blot. Leucine-enriched feeding increased mean sprint power by 2.5% (99% confidence limits, ±3.1%; P = 0.013) and reduced overall tiredness during sprints by 13% (90% confidence limits, ±9.2%). Serum creatine kinase was 19% (90% confidence limits, ±18%) lower than control, but difference in lactate dehydrogenase and muscle pain were trivial and unclear. In the second study, protein-carbohydrate feeding led to moderate and very large increases in cell signalling to translation; mTOR, 4E-BP1 and RPS6 phosphorylation by 3-h. Bioinformatics analysis indicates protein ingestion effects the transcriptome response involved in immune/inflammatory processes, tissue development (extracellular matrix, cytoskeletal, and scarcomere remodelling), and metabolism consistent with increased fatty acid oxidation, compared to control. Post-exercise protein and carbohydrate coingestion during a period of hard training enhances subsequent high-intensity endurance performance and may reduce membrane disruption in comparison to high-carbohydrate feeding. Furthermore, the mechanism responsible for protein-nutrition mediated adaptation may be through enhancing protein translation and fine-tuning the gene expression profile induced by exercise.
  • Thumbnail Image
    Item
    Assessment of nutritional knowledge and food skills in talented adolescent athletes : a thesis presented in partial fulfillment of the requirements for the degree of Master of Science in Human Nutrition at Massey University, Palmerston North, New Zealand
    (Massey University, 2010) Burkhart, Sarah Jane
    There is very limited research on the nutrition knowledge and food skills of elite athletes in New Zealand. Adolescent athletes are moving through an important physiological stage of life, as well as training and competing in their chosen sports. These athletes are the future New Zealand sporting representatives and therefore need adequate nutrition knowledge for performance, as well as health and wellbeing. This research investigated the basic and sports nutrition knowledge of 100 talented adolescent athletes, aged 13 – 20 years from five team sports using a questionnaire and a focus group. The focus group involved 9 rugby players and investigated currently available nutrition resources. While the participants had a reasonable level of basic nutrition knowledge, their sports nutrition knowledge was not as high. They struggled with the concepts of sports drinks, muscle growth and supplements. Most participants had received some nutrition education and indicated that in the future they would prefer individual sessions with a sports nutritionist, written resources, as well as group sessions including cooking sessions and group workshops, and using a high profile athlete as a role model. The participants were very clear that their coaches and parents needed to be involved in their nutrition education. More research is needed to assess the overall knowledge of New Zealand adolescent athletes and the most appropriate, and effective methods of education for this group.