Fully Funded Swansea University MSc by Research Scholarship: ‘Ultra-Run’: Understanding the metabolic and physiological responses to ultra-endurance running under diets of differing glycaemic impact
Funding provider: Beneo GmbH
Subject areas: Sports & Exercise Sciences, Sports Nutrition, Exercise Biochemistry
Project start date:
- 1 October 2022 (Enrolment open from mid-September)
Supervisors: Professor Richard Bracken (firstname.lastname@example.org) and Dr Rachel Churm (email@example.com)
Aligned programme of study: MSc by research in Sports Science
Mode of study: Full-time
Ultraendurance events have increased in popularity in recent years. Although the provision of exogenous carbohydrate to liver and skeletal muscle is essential for the maintenance of ultraendurance performance, less considered is the differential rate of liver and skeletal muscle glycogen repletion in determining the impact on ultraendurance exercise. The type of carbohydrate may be important in optimising the carbohydrate provision to the exercising athlete. Although ingestion of large amounts of multiple forms of carbohydrate does not seem to differentially impact skeletal muscle glycogen repletion rates, emerging literature supports a metabolic and ergogenic benefit of fructose-glucose carbohydrate sources over glucose polymers via improved post-exercise liver glycogen repletion (Moriarty et al., 1994, Casey et al., 2000, Fuchs et al., 2016, Decombaz et al., 2011). Isomaltulose (Palatinose™) is a disaccharide sucrose isomer with an alpha-1,6 glycosidic bond between glucose and fructose, as opposed to an alpha-1,2 glycosidic bond in sucrose. This slows the hydrolysation rate to 20%–25% of that of sucrose (Gunther et al., 1998), and a glycaemic index value of 32. Emerging metabolic and physiological effects consistently demonstrate (i) reduced post-prandial glucose area under the curve, (ii) concomitantly lower peaks in blood glucose and insulin (iii) conserved CHO oxidation (iv) rehydration, when compared with different carbohydrate sources. Therefore, the research literature supports the role of isomaltulose as an important carbohydrate for endurance activities. However, the full metabolic potential for ingestion has not been realised. This ambitious study will compare the role of isomaltulose against a maltodextrin in acute ultra-endurance exercise and, more broadly in regular physical training.
Methods: In this randomised counter-balanced design, participants will be allocated to a low GI diet (containing isomaltulose) or high GI dietary plan (containing maltodextrin) for 4 weeks under each arm. Within this phase, participants will perform a glycogen depletion protocol and be provided with each carbohydrate as an energetic repletion drink ahead of the performance of an acute running challenge.
Cardio-respiratory, glycaemic, metabolic, stress hormone and stress biomarkers will be detailed. In addition, training volumes, sleep, nutrient intakes will be determined.
The successful postgraduate will join a high performing team under the supervision of Professor Richard Bracken and Dr Rachel Churm.
We offer an excellent opportunity to deepen their understanding of energy metabolism and ultraendurance running.