title: Energy Availability and Dietary Patterns of Adult Male and Female Competitive Cyclists With Lower Than Expected Bone Mineral Density.
abstract: The purpose of this study was to assess energy availability (EA) and dietary patterns of 10 adult (29-49 years) male (n = 6) and female (n = 4) competitive (USA Cycling Category: Pro, n = 2; 1-4, n = 8) endurance cyclists (5 road, 5 off-road), with lower than expected bone mineral density (BMD; Z score < 0) across a season. Energy intake (EI) and exercise energy expenditure during preseason (PS), competition (C), and off-season (OS) were estimated from 3-day dietary records, completed once per month, across a cycling season. BMD was measured by DXA at 0 months/5 months/10 months. The Three-Factor Eating Questionnaire (TFEQ) was used to assess cognitive dietary restraint. Seventy percent of participants had low EA [(LEA); < 30 kcal · kg fat-free mass (FFM) (-1) · day(-1)] during PS, 90% during C, and 80% during OS (range: 3-37 kcal · kg FFM(-1) · day(-1)). Ninety percent of cyclists had LEA during ≥ 1 training period, and 70% had LEA across the season. Seventy percent of cyclists were identified as restrained eaters who consciously restrict EI as a means of weight control. Mean daily carbohydrate intake was below sport nutrition recommendations during each training period (PS: 3.9 ± 1.1 g · kg(-1) · day(-1), p < .001; C: 4.3 ± 1.4 g · kg(-1) · day(-1), p = .005; OS: 3.7 ± 1.4 g · kg(-1) · day(-1), p = .01). There were no differences in EA and EI · kg(-1) between male and female cyclists and road and off-road cyclists. Low EI, and specifically low carbohydrate intake, appears to be the main contributor to chronic LEA in these cyclists. Adult male and female competitive road and off-road cyclists in the United States may be at risk for long-term LEA. Further studies are needed to explore strategies to prevent and monitor long-term LEA in these athletes.
authors.affiliation: Beth-El College of Nursing and Health Sciences, Sport Nutrition, University of Colorado Colorado Springs, Colorado Springs, CO.
authors.forename: Rebecca T
authors.initials: RT
authors.lastname: Viner
authors.forename: Margaret
authors.initials: M
authors.lastname: Harris
authors.forename: Jackie R
authors.initials: JR
authors.lastname: Berning
authors.forename: Nanna L
authors.initials: NL
authors.lastname: Meyer
mesh_terms: D000328:Adult; D056352:Athletes; D001642:Bicycling / Q000502:physiology*; D015519:Bone Density; D004032:Diet; D004040:Dietary Carbohydrates / Q000008:administration & dosage; D002149:Energy Intake; D004734:Energy Metabolism; D005247:Feeding Behavior; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D064133:Sports Nutritional Physiological Phenomena; D011795:Surveys and Questionnaires
chemical_list: D004040:Dietary Carbohydrates