Comparison Of Nutritional Intake And Physical Activity Among Chronotypes In Female College Athletes

Low energy availability (LEA) in female athletes negatively impacts physical health and athletic performance. Adolescents exhibit the later chronotype (sleep-wake cycle) among all age groups. Adequate dietary intake is essential to improve LEA; however, many female collegiate athletes do not meet energy requirements, with notably low breakfast protein intake. PURPOSE: To compare nutritional intake and physical activity in female college athletes between morning and evening chronotypes. METHODS: Twenty-one female college athletes were classified by chronotype using the Morningness - Eveningness Questionnaire (MEQ) developed by Horne and Ostberg into high and low MEQ score groups (high and low groups, respectively). Dietary survey was done using the 4-day food record and athletes' food intake frequency questionnaire. Physical activity during non-training hours was tracked via triaxial accelerometers. Nutrient intake and physical activity were assessed via the dietary record method at 8 time points, every 3 hours starting at midnight. Statistical analyses were performed using SPSS ver. 26 (p < 0.05), with Wilcoxon's rank sum test for non-normally distributed variables and independent Student's t-test for normally distributed variables. RESULTS: The MEQ score was 58 ± 8, with 11 and 10 athletes in the high (58 ± 6) and low (46 ± 4) groups, respectively. Total energy intake was 2525 ± 757 and 1943 ± 662 kcal/day (p = 0.08), while breakfast energy intake was 497 ± 152 and 319 ± 187 kcal (p < 0.03) for the high and low groups, respectively. Physical activity from 0-3 p.m. and 9-12 p.m. were significantly higher in the high group than in the low group (p < 0.05). CONCLUSIONS: The near-morning chronotype female athletes had a higher early-morning energy intake and higher physical activity excluding training time than the near-evening chronotype athletes.