Examination Of Low Energy Availability And Bone Health In Endurance Trained Runners

Low energy availability (LEA) is prevalent in both male and female endurance runners; however, limited research has examined LEA and micronutrient distribution necessary to build peak bone mass. PURPOSE: To examine energy availability (EA) and low bone mineral density (BMD) in male and female endurance runners. Examine the association between EA and BMD and micronutrients associated with bone health (i.e., calcium, vitamin D, vitamin C, vitamin K, iron, magnesium, zinc) METHODS: A cross-sectional study examined collegiate and recreational endurance runners (n=17; ages 19.4±1.1 years; males: n=7, height: 180.4±6.6 cm, weight: 68.1±5.5 kg and females: n=10, height: 162.2±5.8 cm, weight 58.0±7.9 kg). Runners completed height, weight, a Dual X-Ray Absorptiometry (DXA), and resting metabolic rate. For 7 days, participants recorded their food intake and exercise through the ESHA software while also wearing heart rate monitor to track exercise energy expenditure (EEE). Food logs assessed micronutrients related to bone health (calcium, vitamin D, vitamin C, vitamin K, iron, magnesium, zinc). Cross tabulations and chi-square analysis were used to determine the distribution and correlation between LEA, low BMD, and recommendations for micro-nutrient distributions. RESULTS: Overall, EA was 27.7±11.1 kcal/kg FFM (females: 30.8±10.6 kcal/kg FFM, males: 23.3±11.1 kcal/kg FFM); 13.3% (n=2/15) reported low BMD; and 40% (n=6/15) were trending towards risk for low for BMD. For all participants, the following were below recommended values for micronutrients: 82.4% (n=14) for calcium (mg), 88.2% (n=15) for vitamin D (IU), 94.1% (n=16) for magnesium (mg), 94.1% (n=16) for zinc (mg), 70.6% (n=12) for Vitamin C (mg), 70.6% (n=12) for Vitamin K (mcg), and 52.9% (n=9) for Iron (mg). CONCLUSION: Low energy availability was prevalent in both male and female endurance runners. While only 2 met the criteria for low BMD, evidence revealed endurance trained runners trended toward risk for low BMD. A majority of participants were below recommended values for micronutrients that have involvement on bone health. This demonstrates the need for nutritional education to endurance trained runner and coached specifically including proper foods to eat for micronutrient consumption, appropriate EA, and bone health maintenance.