Participants~All participants were informed about the procedures and provided signed informed consent. The study was conducted according to the guidelines of the Helsinki Declaration for Human Research and the protocol was approved by the Ethics Committee/Institutional Review Catholic University of Murcia (Code: CE091802).~Study design~Cyclists were instructed to take the supplement along with breakfast and to continue their usual diet and training schedule. Subjects in both groups were instructed not to consume foods high in citrus flavonoids (grapefruit, lemons or oranges) for 5 days prior to and during the study, this was verified by diet recalls records.~Procedures~Participants visited the laboratory on seven occasions. Visit 1 consisted of a medical examination and blood extraction to determine health status. On visits 2 and 5, a 24-hr diet recall and a Wingate test were performed. On visits 3 and 6, another 24-hour diet recall was conducted, followed by an incremental test until exhaustion on a cycle ergometer. On visits 4 and 7, the 24-hour diet recall was repeated, and participants performed a rectangular test on the cycle ergometer. Prior to each testing session (visits 2, 3, 4, 5, 6 and 7), a standardized breakfast composed of 95.16 g of carbohydrates (68%), 18.86 g of protein (14%) and 11.30 g of lipids (18%) was prescribed by the sport nutritionist.~Pre and post evaluation test~Pre-intervention visits: 1,2,3 and 4 Post-intervention visits: 5,6 and 7~Visit 1:~Health status blood analysis: A general analysis will be performed both in the pre and post-supplementation period. The extraction will be done by venous via. (Fasting)~Medical examination: A clinical history of family and personal history, a resting electrocardiogram (ECG) and a medical examination (auscultation, blood pressure measurement, etc.) will be taken to certify that the person is healthy and not at risk to participate in the study. (Fasting)~Visits 2 and 5:~Resting Metabolic Rate (RMR): A resting test will be performed with the ergospirometer to determine macronutrient supply at rest and caloric expenditure. (Fasting)~Body composition by absorptiometric densitometry (DXA): A body composition test will be performed by the dual energy absorptiometric densitometry technique (X-ray), with the objective of to determine parameters of fat mass, fat-free mass and fat percentage. In addition, anthropometry was also used to determine changes in body composition (fat and muscle mass). (Fasting)~Anaerobic power and mechanical power production: After a standardized breakfast, a Wingate test was performed on a cycloergometer. Wingate test (WAnT) consisted of an all-out 30-s sprint on a cycloergometer (Monark Ergomedic 894E Peak Bike, Vansbro, Sweden). Breaking resistance was held constant at 7.5% of each individual's body mass. All participants were verbally encouraged to pedal as fast as possible during the entire sprint.~Visits 3 and 6:~Incremental step with final ramp test was performed on a cycle ergometer using a metabolic cart (Metalyzer 3B. Leipzig, Germany) to determine maximal fat oxidation zone (FatMax), ventilatory thresholds 1 (VT1) and 2 (VT2) and maximal oxygen consumption (VO2max). Participants began cycling at 35W for 2 min, increasing then by 35W every 2 min until RER>1.05, initialling then the final ramp (+35W·min-1) until exhaustion. The estimated functional threshold power (FTP) was calculated using the following equation [16]:~FTP (W) = Pmax (W) x 0.865 - 56.484.~Visits 4 and 7:~Rectangular test was performed on a cycle ergometer using the power output values resulting from the maximal test (FatMax, VT1 and VT2). Participants exercised continuously from FatMax, to VT1 and to VT2 for 10 min, without rest. Cardiorespiratory variables (VO2, VO2R, carbohydrate oxidation (CHO), fat oxidation (FAT) and cycling economy) were determined for each metabolic zones.~Urine samples~Main hesperidin metabolites were analysed in participants' urine. Urine samples, corresponding to 24 h urine collection from each participant before and after the supplementation, were frozen in liquid nitrogen after collection and thawed for its analysis.~All the data of the subjects who participated in the study were stored under a computer system with a security key. In addition, a record was also made of some of the paper data that was saved under key, and to which only the researchers of this project had access.
This clinical study evaluates the effect of 500 mg of 2S-hesperidin for 8 weeks on performance (power generated in different metabolic zones), body composition (fat and muscle mass) and biochemical (antioxidant, inflammatory status) and metabolic (capillary blood in finger) markers in amateur cyclists. Our hypothesis is that chronic intake of 2S-hesperidin can improve performance (maximum power generated). To justify this hypothesis, we measured the parameters mentioned above, which could establish a cause-effect relationship between 2S-hesperidin intake and possible yield improvement.