The determination of blood glucose response to various carbohydrate foods may help athletes in their choice of preexercise feedings. This case study documented the postprandial glycemic responses of three male endurance athletes at rest after ingestion of 50-gram portions of three carbohydrate foods: graham crackers, orange juice, and oatmeal. Plasma glucose response differed in each subject for each test food. Two of the three subjects exhibited similar glycemic responses, but not to the same test food. Future studies will clarify the relationship between carbohydrate ingestion and postprandial glucose response.
Marie Dunford and Charlotte Saunders
Thomas D. Brown
Numerical approximation of the solutions to continuum mechanics boundary value problems, by means of finite element analysis, has proven to be of incalculable benefit to the field of musculoskeletal biomechanics. This article briefly outlines the conceptual basis of finite element analysis and discusses a number of the key technical considerations involved, specifically from the standpoint of effective modeling of musculoskeletal structures. The process of conceiving, developing, validating, parametrically exercising, and interpreting the results of musculoskeletal finite element models is described. Pertinent case study examples are presented from two series of finite element models, one involving total hip implant dislocation and the other involving femoral head osteonecrosis.
Siobhan T. Moran, Christine E. Dziedzic and Gregory R. Cox
The aim of this case study was to describe the race nutrition practices of a female runner who completed her first 100-km off-road ultraendurance running event in 12 hr 48 min 55 s. Food and fluid intake during the race provided 10,890 kJ (736 kJ/hr) and 6,150 ml (415 ml/hr) of fluid. Hourly reported carbohydrate intake was 44 g, with 34% provided by sports drink. Hourly carbohydrate intake increased in the second half (53 g/hr) compared with the first half (34 g/h) of the race, as the athlete did not have access to individualized food and fluid choices at the early checkpoints and felt satiated in the early stages of the race after consuming a prerace breakfast. Mean sodium intake was 500 mg/hr (52 mmol/L), with a homemade savory broth and sports drink (Gatorade Endurance) being the major contributors. The athlete consumed a variety of foods of varying textures and tastes with no complaints of gastrointestinal discomfort. Despite thinking she would consume sweet foods exclusively, as she had done in training, the athlete preferred savory foods and fluids at checkpoints during the latter stages of the race. This case study highlights the importance of the sports nutrition team in educating athletes about race-day nutrition strategies and devising a simple yet effective system to allow them to manipulate their race-day food and fluid intake to meet their nutritional goals.
Kevin Thompson, Stephen Garland and Fiona Lothian
Thompson and Cooper1 observed that improvements in the swimming speed at 2-mM and 6-mM lactate concentration coincided with improvements in competitive breaststroke performances, whereas Pyne et al2 concluded that changes in swimming speed at lactate threshold were not directly associated with competition performances in a mixed-stroke group of 12 elite swimmers. This case study presents data from eleven (7 × 200 m) step tests over a 3-year period for a world-class 200-m male breaststroke swimmer. Personal-best race times were reduced by 9.5 seconds over this period. For this individual, step-test data provided valuable information with regard to the swimmer’s readiness for performance, health and training status, and nutritional habits.
Barbara D. Eden and Peter J. Abernethy
The food and fluid intake of a male ultraendurance runner was recorded throughout a 1,005-km race completed over 9 days. The nutrient analysis showed an average daily energy intake of 25,000 kJ with 62% from carbohydrate, 27% from fat, and 11% from protein. Carbohydrate intake was estimated to be 16.8 g ·
Alice K. Lindeman
Meeting the energy demands of ultraendurance cycling requires careful planning and monitoring of food and fluid intake. This case study presents the nutrient intake of a cyclist while training for and competing in the Race Across AMerica (RAAM). Carbohydrate accounted for 65% of the calories consumed during training (4,743 kcal), 75% during 24-hr races (10,343 kcal), and 78% during RAAM (8,429 kcal). Gastrointestinal complaints during RAAM included nausea, feeling of fullness, and abdominal distension. Although probably exacerbated by sleep deprivation, these problems were all diet related. Based on this experience, it appears that by controlling the carbohydrate concentration of beverages, limiting dietary fiber, and relying on carbohydrate as the primary energy source, one could both control gastrointestinal symptoms and promote optimal performance in training and in ultramarathon cycling.
Kevin G. Thompson and Stephen W. Garland
Competitive swimmers routinely undertake a 7 X 200-m incremental step test to evaluate their fitness and readiness to compete.1 An exercise protocol more closely replicating competition swimming speeds may provide further insight into the swimmer’s physiological and technical readiness for competition. This case study reports data over a 3-year period from 11 Race Readiness Tests, which were completed, in addition to the 7 X 200-m test, as an attempt to provide the swimmer and coach with a fuller assessment. For this individual, data provided objective information from which to assess training status and race readiness following a transition from 200-m to 100-m race training. Data also raised a question as to whether a 100-m maximal effort 10 minutes before another one actually enhances performance owing to a priming effect.
After graduating from college and entering the work force, young adult athletes often struggle with the task of fueling themselves optimally for top performance and weight control. The stresses and time constraints of work, family, and social responsibilities often result in eating fast foods on the run. These young adults can benefit from nutrition education programs at the worksite, at health clubs, in the community, and via the media. Dietitians who specialize in sport nutrition have particular appeal to these athletes, who are struggling to eat well, exercise well, and stay lean yet put little time or effort into their food program. This article includes two case studies of young adults and the dietary recommendations that taught them how to make wise food choices, fuel themselves well for high energy, and control their weight.
Jessica Brooke Kirby and Mary Ann Kluge
Older adults are often viewed by society more for what they cannot do than for what they are capable of achieving. This intrinsic case study examined the formation of a women’s 65+ volleyball team at a university for the purpose of better understanding what it was like for older women to learn a new sport and what meaning participating in competitive sport had for those who had not previously been considered athletic. Qualitative methods explored each participant’s experiences through a focus group, individual interviews, observational notes, and written reflections. Resulting team member themes included going for the gusto, belonging to a team, and support from the university. This program is a potential model to engage nonathletic older adults in sport, while forging a new and positive aging framework for aging athletes.
Guy Faulkner and Stuart J.H. Biddle
Research continues to support the consideration of exercise as an adjunctive treatment for depression. Adopting a qualitative approach, the aim of this study was to extend our understanding of the motives and barriers to exercise faced by this clinical population, and to explore the role of physical activity in promoting psychological well-being, in a way that encompasses the variability and contextuality of the lives of individuals. Marking a departure from standard content analyses reported in the literature, instrumental case studies are developed that offer a different format for representing qualitative data. Given its longitudinal nature, this study demonstrates the fundamental importance of considering the wider context of participants’ lives in order to understand the relationship between physical activity and psychological well-being. This association is likely to be complex and highly idiosyncratic. Such an understanding may inform a more critical insight into the potential of exercise as an antidepressant in terms of process and effectiveness.