Browsing by Author "Potgieter, Sunita"

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    The effect of caffeine supplementation on Olympic-distance triathletes and triathlon performance in the Western Cape, South Africa
    (Stellenbosch : Stellenbosch University, 2013-03) Potgieter, Sunita; Smith, Carine; Wright, H. H.; Warnich, L.; Nel, D. G.; Stellenbosch University. Faculty of Medicine and Health Sciences. Dept. of Interdisciplinary Health Sciences. Human Nutrition.
    ENGLISH ABSTRACT: Background: Abundant evidence supporting the ergogenic effect of caffeine during endurance exercise exists. Single sporting events, laboratory based studies and inappropriate research design questions the applicability of these studies to triathlon performance. Objectives: The main aims of this study were to i) investigate the ergogenic effect of caffeine supplementation during a triathlon; ii) evaluate parameters that could in part explain why caffeine supplementation is ergogenic, iii) investigate possible factors influencing the ergogenicity of caffeine supplementation and iv) investigate possible confounding factors influencing triathlon performance. Methods: A double-blind, randomized, crossover, controlled, clinical field trial was conducted. Performance data (time to complete (TTC), rating of perceived exertion (RPE) and mood state), parameters explaining the mechanism of action (endocrine-stress response, oxidative stress and plasma lactate), factors influencing ergogenicity (lifestyle, gender and genetics) and triathlon performance (general health, energy- and nutrient intake, body composition, training regime, side-effects of caffeine withdrawal- and supplementation and hydration status) was collected during two Olympic-distance triathlons (T1 and T2). Results: Twenty six Caucasian triathletes (Nm=14, Nf=12) participated (age: 37.8±10.6 years, habitual caffeine intake: 412.7±504.8 mg/day, percentage body fat: 14.5±7.2 %, training/week: 12.8±4.5 hours). There was a 3.7% reduction in swim time (33.5±7.0 vs. 34.8±8.1 minutes) (p=0.05*) and a 1.3% reduction in the overall time to complete the triathlon (149.6±19.8 vs. 151.5±18.6 minutes) (p=0.02*) in the caffeine group. Caffeine did not statistically influence mood state (p=0.72) or RPE (p=0.87), however, a trend was observed for decreased RPE values in the caffeine group. Caffeine supplementation made no difference to markers of endocrine-stress, except for cortisol, which increased beyond the effect observed from exercise (p=0.00*). Oxidative stress was more pronounced in the caffeine group, as seen with elevated leukocyte (p=0.05*), lymphocyte (p=0.05*) and monocyte (p = 0.05*) counts. Caffeine facilitated greater blood lactate accumulation (p=0.04*). Lifestyle, menstrual cycle, menopause, oral contraceptive use and CYP1A2 gene polymorphisms did not statistically influence the effect of caffeine supplementation on triathlon performance. The mean energy- and nutrient intake two days before T1 and T2 was low for energy (36.5±17.6 and 38.9±18.2 kcal/kg BW), estimated energy availability (estEA) (27.9±28.0 and 28.8±25.6 kcal/kg fat free mass) and carbohydrate (CHO) intake (4.1±1.6 and 4.6±2.5 g/kg body weight (BW)) compared to recommendations. The pre-event meal was low in CHO (0.7±0.4 and 0.7±0.5 g/kg BW) and only 62% (N=16) ingested a carbohydrate-electrolyte solution during T1 (CHO: 1.6±2.3 g/kg BW) and T2 (CHO: 0.7±0.4 g/kg BW). Eighty-five percent (N=22) used supplements. Seventy-two percent of pre-menopausal (Nf pre-men=5) and 40% of post-menopausal (Nf post-men=2) females were osteopenic. Of the males, 18% (Nm<50 = 2) had low anterior-posterior spine BMD and 33% (Nm>50 = 1) were osteopenic. Caffeine withdrawal presented as headaches (46%, N=12) and flu-like symptoms (38%, N=10). Side effects of caffeine experienced included shakiness (42%, N=11), heart palpitations (38%, N=10) and gastrointestinal disturbances (38%, N=10). Plasma volume and hydration was not influenced (p=0.70). Conclusion: Caffeine enhanced triathlon performance, but the effect was not as pronounced as seen in previous laboratory trials and did not affect RPE or mood state. Caffeine supplementation augments the endocrine-stress response by further increasing cortisol levels beyond that resulting from endurance exercise and it induces leukocytosis, neutrophillia and lymphocytosis, suggesting the primary ergogenic effect of caffeine may result due to stimulation of both the central and autonomic nervous systems. Lifestyle, gender and genetics did not significantly influence caffeine’s effect on triathlon performance in this cohort. The subjects had low energy, estEA and carbohydrate intake and a high prevalence of osteopenia.
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    Staff and student health and wellness at the Faculty of Medicine and Health Sciences, Stellenbosch University : current status and needs assessment
    (MedPharm Publications, 2017) Koen, Nelene; Philips, Lauren; Potgieter, Sunita; Smit, Yolande; Van Niekerk, Evette; Nel, Daan G.; Visser, Janicke
    Background: Emphasis is currently placed on the importance of employee and student wellness initiatives. The aim was to assess staff and student health status at the Faculty of Medicine and Health Sciences (FMHS), Stellenbosch University (SU), and to conduct a wellness needs assessment. Methods: Online, self-administered questionnaires were used to collect data concerning staff and students. Additionally, students’ anthropometric and biochemical parameters were assessed. Summary statistics, correlation coefficients and appropriate analysis of variance were used for data analyses. Results: Data were obtained from staff (survey: n = 300) and students (screening: n = 536; survey: n = 330). Some 58% (n = 174) of staff had a self-reported BMI of ≥ 25 kg/m2 whilst mean screening values for all variables fell within normal reference ranges for students. In all, 78% (n = 232) of staff reported to exercise < 150 min/week and 28% (n = 91) of students were sedentary for > 8 h/day; 63% (n = 188) of staff expressed the need to make better food choices, 17% (n = 55) of students were aware of the need to change but experienced reluctance, and both staff and students felt dietary assistance would be beneficial (43% vs. 46%). In addition, 79% of staff (n = 208) and 42% of students (n = 138) reported being under constant pressure. Conclusion: Much can be done to improve the health and well-being of both staff and students at the FMHS, SU. Wellness is a multifactorial concept; as such, health-promotional strategies for classrooms and workplaces should consider all factors in order to provide a holistic approach and potentially identify those who are at risk of a sub-optimal wellness status. (Full text of the research articles are available online at www.medpharm.tandfonline.com/ojfp) S Afr Fam Pract 2018; DOI: 10.1080/20786190.2017.1396788
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    Wellness as a virtue in health sciences students : are they practising what they preach?
    (MedPharm Publications, 2015) Potgieter, Sunita
    Collective and individual greatness are keystones of Health Science education. Enabling prospective healthcare providers to better the quality of life of the population they serve is vital to ensure collective greatness. However, collective greatness can only be achieved once a student is able to attain and retain individual greatness. Self-care, a necessary human regulatory function under individual control, is part and parcel of individual greatness. Healthcare providers can only care for others once they have established, and are able to, care for themselves.