Do we need to change the guideline values for determining low bone mineral density in athletes?

Off- to in-season body composition adaptations in elite male and female endurance and power event athletics competitors: an observational study

BACKGROUND

Monitoring elite athletes' body composition (BC) is vital for health and optimizing performance in sports emphasizing leanness, such as athletics. This study aims to investigate and compare sex- and event-specific off-to in-season BC changes in endurance and power event athletics competitors.

METHODS

Elite male and female endurance athletes (> 800 m runners; n = 21) and power event athletes (sprinters, jumpers; n = 32) underwent dual-energy X-ray absorptiometry (DXA) scans for whole and regional lean mass (LM), fat mass (FM), bone mineral content (BMC), and density (BMD) during off-season (September-October) and in-season (April-May). Linear mixed models tested between-group off-season differences in BC, within-group off-season to in-season changes, and between-group differences in change. To assess meaningful or least significant changes (LSC) in BC, DXA precision errors were determined from two consecutive total body scans in a subsample of athletes (n = 30).

RESULTS

Male athletes (n = 26) gained significantly (p < 0.05) more body mass (BM; mean difference 1.5 [95% confidence interval (CI):0.5-2.4] kg), LM (843 [95% CI:-253:1459] g), and trunk LM (756 [-502:1156] g) than female athletes (n = 27). The proportion of changes in athlete's BC exceeding the LSC threshold for LM and trunk LM were 70% and 65% in males, and 48% and 26% in females. Significant (p < 0.05) within-group off-season to in-season increases in LM were found for male endurance and power athletes, and female power athletes. All groups significantly increased BMD (p < 0.05). Only male and female power athletes had significant in- to-off-season increases in BMC. 80% of all athletes who had a meaningful increase in BMC belonged to the power event group. No significant within- or between group change in FM was observed.

CONCLUSIONS

The present study found that male athletes gained more BM, LM and trunk LM than females. Within-group increases in regional and whole-body LM and BMC were predominantly found among power event competitors. Incorporating individual meaningful changes alongside traditional statistics provided additional insights into sex and event-group differences. Future research on elite athletic event groups should include DXA measurements closer to major outdoor-season competitions, coupled with site-specific measures (ultrasound, MRI) for better detection of subtle changes in LM and FM.

Assessment of Relative Energy Deficiency in Sport (REDs) Risk among Adolescent Acrobatic Gymnasts

Energy imbalance exposes athletes to relative energy deficiency in sports (REDs) syndrome. Data on energy consumption, REDs, and bone mineral density (BMD) in adolescent acrobatic gymnasts, especially in males, are scarce. Our aim was to examine the eating habits, energy balance, body composition, and BMD of these athletes. In this study, 18 healthy adolescents participating in competitive acrobatic gymnastics completed a questionnaire, underwent a dual-energy X-ray absorptiometry scan (DXA), received a food log, and had their activities monitored for 3 days. Eighteen acrobats were enrolled (mean age: 14.3 ± 1.2 years; males: 6/18). The mean total body BMD Z-score was 0.4 ± 1.0. Top-position acrobats (7/18) had significantly lower total body BMD Z-scores than base-positioned acrobats (-0.2 ± 0.3 vs. 0.8 ± 0.3, p = 0.032), though their forearms were not significantly different (0.2 ± 0.5 vs. 0.8 ± 0.7, p = 0.331). No sex differences were found for BMD Z-scores, BMI, or energy availability. The BMD parameters of the acrobats were within the normal range for a healthy pediatric population, although three had low BMDs (<-1 SD) for healthy athletes. Total body and LS BMD Z-scores were significantly lower in top-position athletes compared to base-position athletes. These findings suggest personalized (top vs. base) training programs (high-impact training) that may achieve better health outcomes.

Skeletal site-specific effects of jump training on bone mineral density in adults: a systematic review and meta-analysis

Preserving or preventing declines in bone mineral density (BMD) is imperative. As jumping is a high-impact bone-loading action, this meta-analysis evaluated the efficacy of jump training to improve BMD and bone turnover relative to non-jumping controls in men and women > 18 years, following Preferred Reported Items for Systematic Reviews and Meta-Analysis guidelines. PubMed and COCHRANE Library databases were searched until February 2022. Fifteen articles (19 jumping-trials) met the predetermined search criteria. Eighteen trials were included for BMD data (n = 666 participants). There was a significant small-moderate effect of jumping on femoral neck BMD (%mean difference: 95%CI, +1.50%: 0.83%; 2.17%, p < 0.0001), that remained significant after sub-analysis by age for both younger (+1.81%: 0.98%; 2.65%) and older adults (+1.03%: 0.02%; 2.03%). BMD of total hip (+1.26%: 0.56%; 1.96% vs + 0.06%: -0.96%; 1.08%), and trochanter (+0.84%: 0.20%; 1.48% vs -0.16%: -1.08%; 0.76%) increased significantly with jump training only in younger adults and non-significantly at the lumbar spine (+0.84%: -0.02%; 1.7% vs -0.09%: -0.96%; 0.77%) only in younger but not older adults, respectively. The BMD response to jump training appears to be site-specific, with the highest sensitivity at the femoral neck. No dose-response effect suggests moderate certainty of a gain in femoral neck BMD when performing the median jump-load of 50 jumps four times weekly.

Prevalence of low energy availability in 25 New Zealand elite female rowers - A cross sectional study

OBJECTIVES

To quantify energy availability (EA) in elite female rowers, determine its association with bone mineral density (BMD), and examine the ability of the low energy availability in females-questionnaire (LEAF-Q) and brief eating disorder in athletes-questionnaire (BEDA-Q) to distinguish between low and normal EA.

DESIGN

Observational cross-sectional study.

METHODS

Twenty-five elite female rowers participated in the study. EA was calculated by means of a 4-day food intake diary and analysis of training load. Low energy availability (LEA) was defined as EA <30 kCal * kg-1 * FFM-1 * day-1. Dual-energy X-ray absorptiometry (DXA) was used to assess fat free mass (FFM) and BMD Z-scores. LEA risk was assessed using the LEAF-Q and BEDA-Q.

RESULTS

The mean EA was 23.2 ± 12.2 kCal * kg-1 * FFM-1 * day-1. Prevalence of LEA was 64 %. The mean BMD Z-score was 1.6 ± 0.6 (range: 0.7 to 2.9). Athletes with LEA had a significantly higher BEDA-Q score than the group with normal EA (mean 0.30 ± 0.17 vs. 0.09 ± 0.11, P < 0.05), but LEAF-Q score was not different between groups (mean 10.4 ± 4.6, 8.2 ± 4.5, P = 0.29).

CONCLUSION

Low energy availability is common amongst elite female rowers in New Zealand and is positively correlated with higher scores on the BEDA-Q. Bone mineral density was normal irrespective of EA status.

Comparison of Bone Quality Among Winter Endurance Athletes with and Without Risk Factors for Relative Energy Deficiency in Sport (REDs): A Cross-Sectional Study

Relative Energy Deficiency in Sport (REDs) is a syndrome describing the relationship between prolonged and/or severe low energy availability and negative health and performance outcomes. The high energy expenditures incurred during training and competition put endurance athletes at risk of REDs. The objective of this study was to investigate differences in bone quality in winter endurance athletes classified as either low-risk versus at-risk for REDs. Forty-four participants were recruited (M = 18; F = 26). Bone quality was assessed at the distal radius and tibia using high resolution peripheral quantitative computed tomography (HR-pQCT), and at the hip and spine using dual X-ray absorptiometry (DXA). Finite element analysis was used to estimate bone strength. Participants were grouped using modified criteria from the REDs Clinical Assessment Tool Version 1. Fourteen participants (M = 3; F = 11), were classified as at-risk of REDs (≥ 3 risk factors). Measured with HR-pQCT, cortical bone area (radius) and bone strength (radius and tibia) were 6.8%, 13.1% and 10.3% lower (p = 0.025, p = 0.033, p = 0.027) respectively, in at-risk compared with low-risk participants. Using DXA, femoral neck areal bone density was 9.4% lower in at-risk compared with low-risk participants (p = 0.005). At-risk male participants had 21.9% lower femoral neck areal bone density (via DXA) than low-risk males (p = 0.020) with no significant differences in females. Overall, 33.3% of athletes were at-risk for REDs and had lower bone quality than those at low-risk.

Primary, secondary and tertiary prevention of Relative Energy Deficiency in Sport (REDs): a narrative review by a subgroup of the IOC consensus on REDs

Relative Energy Deficiency in Sport (REDs) is common among female and male athletes representing various sports at different performance levels, and the underlying cause is problematic low energy availability (LEA). It is essential to prevent problematic LEA to decrease the risk of serious health and performance consequences. This narrative review addresses REDs primary, secondary and tertiary prevention strategies and recommends best practice prevention guidelines targeting the athlete health and performance team, athlete entourage (eg, coaches, parents, managers) and sport organisations. Primary prevention of REDs seeks to minimise exposure to and reduce behaviours associated with problematic LEA. Some of the important strategies are educational initiatives and de-emphasising body weight and leanness, particularly in young and subelite athletes. Secondary prevention encourages the early identification and management of REDs signs or symptoms to facilitate early treatment to prevent development of more serious REDs outcomes. Recommended strategies for identifying athletes at risk are self-reported screening instruments, individual health interviews and/or objective assessment of REDs markers. Tertiary prevention (clinical treatment) seeks to limit short-term and long-term severe health consequences of REDs. The cornerstone of tertiary prevention is identifying the source of and treating problematic LEA. Best practice guidelines to prevent REDs and related consequences include a multipronged approach targeting the athlete health and performance team, the athlete entourage and sport organisations, who all need to ensure a supportive and safe sporting environment, have sufficient REDs knowledge and remain observant for the early signs and symptoms of REDs.

Evaluating the Suitability of the Low Energy Availability in Females Questionnaire (LEAF-Q) for Female Football Players

BACKGROUND

The Low Energy Availability in Females Questionnaire (LEAF-Q) is a screening tool developed to detect endurance athletes and dancers at risk for development of persistent low energy availability (LEA) and the female athlete triad (Triad). This study investigated the applicability of the LEAF-Q in a cohort of sixty professional female football players.

METHODS

The participants were classified as at risk (≥ 8) or not at risk (< 8) for persistent LEA and the Triad according to their LEAF-Q score, before being compared. Receiver operating curves were then conducted to examine the ability of the overall LEAF-Q and subcategories to correctly determine the presence of clinically defined markers of the Triad. Additionally, Youden's index was calculated to determine the best fitting cut-off values.

RESULTS

Thirty-two percent of participants were classified as at risk by the LEAF-Q. We found no statistically significant differences between the two groups for any markers associated with persistent LEA. Except for acceptable accuracy in determining menstrual status, all other LEAF-Q components exhibited poor accuracy and predictive values. Youden's index scores imply that increasing the overall and injury cut-off values to ≥ 10 and ≥ 5 respectively, would yield increased performance.

CONCLUSIONS

Our findings do not support the use of the LEAF-Q for the purpose of detecting LEA and Triad conditions among female football players.

Bone health in Norwegian female elite runners: a cross-sectional, controlled study

Objective

The primary objective was to compare bone mineral density (BMD) in Norwegian female elite long-distance runners with a control group of inactive females. Secondary objectives were to identify cases of low BMD, to compare the concentration of bone turnover markers, vitamin D and symptoms of low energy availability (LEA) between the groups, and to identify possible associations between BMD and selected variables.

Methods

Fifteen runners and fifteen controls were included. Assessments included dual-energy X-ray absorptiometry measurement of BMD in the total body, lumbar spine and dual proximal femur. Blood samples included endocrine analyses and circulating bone turnover markers. The risk of LEA was assessed through a questionnaire.

Results

Runners had higher Z-scores in the dual proximal femur (1.30 (0.20 to 1.80) vs 0.20 (-0.20 to 0.80), p<0.021) and total body (1.70 (1.20 to 2.30) vs 0.90 (0.80 to 1.00), p<0.001). The lumbar spine Z-score was similar between groups (0.10 (-0.70 to 0.60) vs -0.10(-0.50 to 0.50), p=0.983). Three runners had low BMD (Z-score <-1) in the lumbar spine. Vitamin D and bone turnover markers showed no differences between the groups. Forty-seven per cent of the runners were at risk of LEA. Dual proximal femur BMD showed a positive correlation to estradiol and a negative correlation to LEA symptoms in runners.

Conclusion

Norwegian female elite runners had higher BMD Z-score in the dual proximal femur and total body compared with controls, while no difference was observed in the lumbar spine. The advantages of long-distance running on bone health seem to be site specific, and there is still a need for the prevention of LEA and menstrual disorders in this group.

The effect of the exercise environment and the level of involvement on bone mineral health

INTRODUCTION

This study aimed to compare athletes practicing exercise in different environments with non-active young and elderly men and women regarding bone mineral density (BMD), hypothesizing that BMD values differ between athletes according to the environment of exercise practice, but those training in a low-gravitational environment have no different stimuli to BMD increasing if compared with healthy peers experiencing reduced exercise involvement, whatever the age group and sex.

MATERIALS AND METHODS

104 participants of both sexes were selected according to the environment of exercise practice [swimmers (N = 26) and judo fighters (N = 26)], and exercise level of involvement [non-active young (N = 26) and older adults (N = 26)]. Dual-energy X-ray absorptiometry provided BMD, lean mass, and fat mass (FM) for the whole body (WB), upper (UL), and lower limbs (LL).

RESULTS

For the BMD in WB, UL and LL no effects of group and sex were observed (p > 0.05). Post-hoc analyses detected higher values of BMD in UL for female swimmers compared to non-active older adults (p < 0.05), while judo fighters showed higher BMD in WB, UL, and LL than other participants whatever the sex (p < 0.01). Lower FM was observed for WB, UL, and LL when swimmers and judo fighters were compared to non-active young and older female peers (p < 0.01).

CONCLUSION

The findings emphasized that BMD stimuli with swimming are reduced when compared to judo, and despite the stimuli in swimming is not distinguishable from that affecting BMD in WB, UL and LL of non-active young, it is effective in differing BMD in UL among non-active older for women.

Empowered, Yet Vulnerable: Motives for Sport Participation, Health Correlates, and Experience of Sexual Harassment in Female Combat-Sport Athletes

Background: To explore motives for combat sport participation, weight regulation practices, symptoms of low energy availability (LEA), disordered eating (DE) or eating disorders (ED), and any experiences with sexual harassment (SH) among female combat-sport athletes. Methods: In total, 29 athletes were recruited by social media and in clubs. Participants responded to a questionnaire on health behavior and mental health and completed diet registration and a DXA-scan. Results: Most athletes started combat sports to feel empowered and experienced an inclusive milieu, but the frequency of health issues was high. A total of 21−67% had symptoms of ED, suffered from injuries, had low site-specific BMD, and/or symptoms of LEA. Athletes had insufficient intake of energy and nutrients, and <50% received any dietary information or guidance from their clubs. Most athletes complied with favorable weight-loss strategies; still, >20% used unfavorable methods and rapid weight-loss periods. A total of 70% of the athletes had experienced SH, of which 41% experienced SH within the combat-sport context. Conclusion: Combat sport offers an inclusive milieu, which may increase women’s health and confidence; still, our results indicates a need for actions to safeguard female combat-sport athletes’ mental and physical health, implying a cultural change within the community of combat sport and a need for increased health and nutrition literacy.