Lactose as an Alternative Carbohydrate in Sports Food Within Male Athletes.

INTERVENTION: This study will include 9 visits to the laboratory per participant including: 1. Familiarisation trial of the performance test, and measurements of VO2 ma Xand Wmax. The familiarisation trial is anticipated to take approximately 2.5 hours. The VO2 ma Xtest will be conducted only on stationary bikes through gas sampling and converted to VO2 through the Moxus software. 2. On a weekly basis ‐ four steady state rides for 2 hours at 57.5% Wma Xto establish background metabolism of 13C. These background visits will also take approximately 2.5 hours. 3. On a weekly basis and two days after each of the background tests ‐ four experimental trials consisting of a 2 hour ride at 57.5% Wma Xand a performance test including 10 X2 minute maximal sprint efforts. These experimental trial visits will take approximately 3 hours to complete, and the washout period between each experimental trial is 7 days for each participant. During the experimental trials, carbohydrate drinks will be provided at 15 minute intervals. The drinks will consist of either lactose, sucrose, lactose‐fructose blend or a fructose‐maltodextrin blend. The lactose and sucrose will be ingested at 0.8 g/min with a concentration of 6%. The lactose‐fructose blend will be ingested at 1.5 g/min with lactose at 0.8g/min and fructose at 0.7 g/min. The maltodextrin‐fructose blend will also be ingested at 1.5g/min with maltose at 0.8g/min and fructose at 0.7g/min. The drinks will be 200 ml per serve and also all contain lime juice (16 g/L), citric acid (1.0 g/L) and NaCl (20mmol/L). To monitor adherence, each cyclist will have an individual researcher responsible for supplying the drinks and ensuring that the full dose is completed and on time. CONDITION: Diet and Nutrition ‐ Other diet and nutrition disorders Musculoskeletal ‐ Normal musculoskeletal and cartilage development and function Sporting Performance; ; Sporting Performance PRIMARY OUTCOME: Mean power in the performance test. The performance test will include ten maximal sprints consisting of roughly 2 minutes each. This will not assess a specific muscle group, but overall physical fitness instead. [End of exercise procedure for each study arm, approx. 2 hours after steady state cycling. ] INCLUSION CRITERIA: Endurance trained, lactose tolerant males with a VO2 ma X> 50 ml.kg/min SECONDARY OUTCOME: .Exogenous carbohydrate oxidation during exercise. Carbohydrate oxidation will be calculated using the breath analysis through calculations described in the study below. ; ; 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. ; [.During the second hour of the 2‐h ride at 57.5%Wmax. Collected every 30 mins starting from minute 58. ] Endogenous carbohydrate oxidation during exercise. Carbohydrate oxidation will be calculated using the breath analysis through calculations described in the study below. ; ; 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. ; [During the second hour of the 2‐h ride at 57.5%Wmax. Collected every 30 mins starting from minute 58. ] Endogenous fat oxidation rate. Fat oxidation will be calculated using the breath analysis through calculations described in the study below. ; ; 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. ; [During the second hour of the 2‐h ride at 57.5%Wmax. Collected every 30 mins starting from minute 58. ] Gut comfort. ; ; Psychometric scales, that are designed specifically for this study, will be used to asses gut comfort. [Through out the exercise protocol sampled at 15 min intervals, for a total of 3.5 hours.]