Effect of alternative carbohydrate blends on performance

The interventions are various blends of carbohydrates with details not disclosed. Protocols and procedures: Initial meeting, study explanation and screening for inclusion/exclusion criteria will be provided by a telephone, in person, or online consultation. Participants will be able to ask any questions and have the questions answered. If parties are happy, participants will be invited to sign the consent form. Following which, participants will be asked to complete the health screening questionnaire. If no precluding health issues are revealed, then a date and time for the Visit 1 will be arranged. Visit 1, being VO2max/Wmax test and familiarization trial of the performance test. Participants will modify and record their cycle training and repeat on a weekly basis according to the weekly block: day 1, 3–4 h training ride; days 2, medium-duration ride (2–3 h); day 3, rest or easy intensity training day; day 4, standardized ride in the laboratory (2.5 h simulated cycle race protocol with breath sampling); day 5, rest day or short ride; day 6, experimental trial; and day 7, recovery ride. Day 4 and 6 trials will be conducted at the same time of morning after an overnight fast, 500 mL water, and standardized provided meals and fluid from breakfast the day prior (snacks, dinner provided). To reduce background 13C enrichment, participants will be provided with extensive food lists and instructed not to eat foods with components derived from plants naturally enriched with 13C (i.e., maize, sugar cane) for at least 10 d before the first experimental trial and for the duration of the study. To standardize diet, participants will be provided food based on energy expenditure on protocols days 3-5. These diet patterns will be repeated before each of the subsequent trials. Protocols. Exercise tests will be conducted using the electronically braked cycle ergometers (VeloTron) and expired gas analysis using calibrated systems (Parvomedics and Cosmed). The VO2max/Wmax test will be the standard 2.5 min ramp [1, 3]. Height, weight, and fat and lean mass will be measured using stadiometer and skinfold calipers, On day 4 and 6, 1-2 participants will report to the laboratory between 0600 and 0900 h as arranged. All participants will conduct the same experimental procedures. However, only n=8 will have expired gas collected during exercise. We have calculated that n=8 is sufficient power for the anticipated effect size for this secondary mechanistic outcome and in addition to save costs on limited study budget. The remaining 4 participants will perform the same exercise but without the expired respiratory gas collection. The following two paragraphs describe the metabolic procedures. The test ride on day 4 is to assay 13C background under and to standardize metabolic and training conditions induced by the test carbohydrate used prior to performance testing on day 6, but with carbohydrate comprising background enrichment; it will comprise a 2.25-h ride of the same protocol as the day 6 ride to 135 min. The study drink will comprise the same make-up and concentration as the test drinks, but with carbohydrate containing background 13C enrichment and containing salt and flavorings ingested at the same time points and rate as the test drinks. The metabolic and performance test on day 6 will comprise a modified version of the simulated cycle race protocol used previously [4] consisting of a 2.5-h of stochastic-intensity riding between 30 and 95% Wmax, followed with a double-blind performance test comprising a constant-power time to exhaustion text at 67.5% of Wmax (~74%VO2max). During the stochastic preload, breath samples will be collected during the final 3 min of two 10 min periods at 67.5% Wmax to measure exogenous-carbohydrate, endogenous-carbohydrate (glycogen), and fat oxidation rate during exercise, Expired breath will be collected as triplicate samples into exetainers (Exetainer, Labco Ltd., High Wycombe, UK) and external respiration for VO2 and VCO2 (Moxus, COSMED, Parvomedics). Breath samples will be analyzed in the UK using gas-isotope ratio mass spectroscopy (Sercon, Crewe, UK). On day 6, after arrival at the lab and toileting, participants will have their body mass recorded then will be seated on the Velotron cycle ergometer to complete resting baseline gut comfort and psychometric scales. They will then mount the bike and ingest the first single bolus of test drink and begin the test ride. Gut comfort and psychometric scales will be collected at min 14 of each 15 min sampling block, followed by experimental drink ingestion. During all rides, environmental conditions will be maintained at 21-22oC by air conditioning and ambient relative humidity (50-60%); conditions will be recorded at the beginning, middle and end of the test and parameters will be included as modifying covariates in the statistical analysis. Standardized airflow will be maintained over the subjects by a powerful fan set at a standard rate and position relative to the shoulders and face of the rider and unchanged over the course of the ride or experiment. Carbohydrate drinks. Following the initial 200-mL drink, further 200 mL drinks will be ingested at 15-min intervals. All drinks be delivered double-blind. The total carbohydrate in the drinks and ingestion rate was derived from the mean rate ingested of 1.5 g·min-1 (90 g·h-1) [1, 6]. All drinks will have lime juice (16 g·L-1), citric acid (1.0 g·L-1) and 20 mmol·L-1 (1.17 g·L-1) NaCl. Psychometric scales. The effect of drink on physical exertion, gastrointestinal comfort, and drink sweetness will be recorded at rest, every 30 min during the pre-load ride prior to drink ingestion, but not during the performance test to minimize distraction and to remove time-duration cues for the athlete. 1. O'Brien WJ, Stannard SR, Clarke JA, Rowlands DS. Fructose-maltodextrin ratio governs exogenous and other cho oxidation and performance. Medicine and Science in Sports and Exercise. 2013;45:1814-24. 2. Hopkins WG, Schabort EJ, Hawley JA. Reliability of power in physical performance tests. Sports Med. 2001;31:211-34. 3. O'Brien WJ, Rowlands DS. Fructose-maltodextrin ratio in a carbohydrate-electrolyte solution differentially affects exogenous carbohydrate oxidation rate, gut comfort, and performance. Am J Physiol Gastroint Liver Physiol. 2011;300:G181-G9. 4. Guillochon M, DS R. Solid, Gel, and Liquid Carbohydrate Format Effects on Gut Comfort and Performance. International Journal of Sport Nutrition and Exercise Metabolism. 2017;27:147-54. 5. Odell OJ, Podlogar T, Wallis GA. Comparable Exogenous Carbohydrate Oxidation from Lactose or Sucrose during Exercise. Med Sci Sports Exerc. 2020;52:2663-72. 6. Ijaz A, Collins A, Moreno-Cabañas A, Bradshaw L, Betts J, Podlogar T, et al. Exogenous glucose oxidation during exercise is positively related to body size. Research Square. 2024;PrePrint. 7. Verbraecken J, Van de Heyning P, De Backer W, Van Gaal L. Body surface area in normal-weight, overweight, and obese adults. A comparison study. Metabolism - Clinical and Experimental. 2006;55:515-24. 8. Du Bois D, Du Bois EF. Clinical calorimetry: tenth paper a formula to estimate the approximate surface area if height and weight be known. Archives of Internal Medicine. 1916;XVII:863-71.