Bone Health in Athletes

Bone metabolism, bone mass and structural integrity profile in professional male football players

BACKGROUND

Physical exercise plays an important role in bone mineralization as well as factors involved in bone metabolism influence the athletic performance. In European countries, soccer is the most popular sport. The aim of the study was to investigate bone metabolism, bone mass and structural integrity profile in professional male adult football players.

METHODS

Sixteen professional male football players from a single team of the Second division Italian League (mean age 22.4±0.7 years) were enrolled. Bone biochemical parameters, including serum calcium, phosphorus, albumin, creatinine, alkaline phosphatase, intact plasma PTH, 25-hydroxy-vitamin D (25-OHD), 24-h urinary calcium and phosphorus, and calcaneal quantitative ultrasound (QUS), were evaluated at the beginning (October 2012) and at the end of the League (May 2013).

RESULTS

25-OHD levels were significantly lower at the end of the League compared to the beginning (27.1±5.9 vs. 36.6±9.5 ng/mL, fold change [FC]=0.25, P=0.008), and the prevalence of 25-OHD deficiency increased from 25% to 73%. Moreover, higher rate of previous bone, cartilage or ligament injuries correlated with 25-OHD deficiencies (P=0.014). T-score and Z-score were at the upper limits of the normality ranges, without significant difference between the beginning and end of the League. Phosphaturia was slightly decreased at the end of the League (691.0±364.5 vs. 934.0±274.3 mg/24h, FC=0.26, P=0.06). A significant correlation was found between phosphaturia and BQI (R2=0.28, P=0.03), and both T-s and Z-s (R2=0.28, P=0.03) at the beginning of the League.

CONCLUSIONS

With this pilot study, we demonstrated that vitamin D status significantly worsened at the end of the League. Therefore, vitamin D supplementation might be suggested in adult football players in order to prevent vitamin D deficiency and improve the athletic performance.

Female Collegiate Dancers Body Composition, Macronutrient and Micronutrient Intake Over Two Academic Years: A Longitudinal Analysis

Collegiate dancers face unique challenges to maintain a lean aesthetic, optimal diet, and a high-performance level due to the various stressors in college. The purpose of this study was to examine changes in body composition (BC) and diet over two years. Participants (N = 17, 19.6 ± 1.6 years) completed two laboratory sessions per semester. Sessions included height and weight, BC, dietary intake, and a health history questionnaire. Regardless of rigorous dance training and variations in the academic calendar, no significant changes in BC or diet were observed within semesters of over two years. BMI was normal (24.9 ± 4.1 kg/m²) with fat mass exceeding 30% at all timepoints. Fat mass was negatively correlated with carbohydrate, fat, and protein intake (g/kg/day; r = -0.291, p = 0.004; r = -0.372, p < 0.0001; r = -0.398, p < 0.0001; respectively). Energy intake was within the recommended daily allowance (2040 ± 710 kcal/day), however may be insufficient for an active dance population. Protein (1.1 ± 0.5 g/kg), carbohydrate (3.7 ± 1.6 g/kg), calcium (835 ± 405 mg/day), iron (17 ± 15 mg/day), and potassium (1628 ± 1736 mg/day) intake fell below recommendations for an active population. Alterations in dance training and the demands of the academic calendar may be contributing to suboptimal dietary intake and BC in female collegiate dancers.

Nutritional Risks Among Female Athletes

Background: Limited research studies have been conducted on nutritional risks among female athletes. Therefore, this literature review focuses on rigorously designed studies that examined nutritional risks among female athletes with further recommendations for athletes, coaches, parents, and health professionals, which would help improve the health of female athletes. Methods: This review evaluates the most recent research on nutritional risk among female athletes. Inclusion criteria included peer-reviewed studies of original research on human subjects 13 years of age or older; sample size of N ≥ 19; and studies with a thorough description of their sample and methods. A systematic search of the databases PubMed and Cochrane for published studies (from year 2000 to year 2019) was conducted to identify articles that met inclusion criteria. Bibliographies of identified articles were also searched for relevant articles. Results: Of the 11 studies that met our inclusion criteria, most were mainly cross-sectional in design with few rigorous controls. Findings reveal that strategies to enhance nutrition patterns among female athletes may be important to avoid risks of disordered eating, eating disorders, low energy availability, and symptoms of relative energy deficiency in sports. In addition, general nutrition knowledge is lacking among athletes, sports teams, and coaches. Conclusions: This review highlights the scarcity of evidence-based, rigorous studies examining nutritional risks among female athletes. Findings suggest that interdisciplinary working groups, comprising physicians, sports dietitians, and other supportive health professionals, would be beneficial for female athletes in helping to improve their overall diet, performance, and health.

Transwomen in elite sport: scientific and ethical considerations

The inclusion of elite transwomen athletes in sport is controversial. The recent International Olympic Committee (IOC) (2015) guidelines allow transwomen to compete in the women's division if (amongst other things) their testosterone is held below 10 nmol/L. This is significantly higher than that of cis-women. Science demonstrates that high testosterone and other male physiology provides a performance advantage in sport suggesting that transwomen retain some of that advantage. To determine whether the advantage is unfair necessitates an ethical analysis of the principles of inclusion and fairness. Particularly important is whether the advantage held by transwomen is a tolerable or intolerable unfairness. We conclude that the advantage to transwomen afforded by the IOC guidelines is an intolerable unfairness. This does not mean transwomen should be excluded from elite sport but that the existing male/female categories in sport should be abandoned in favour of a more nuanced approach satisfying both inclusion and fairness.

Nutritional Intake, Sports Nutrition Knowledge and Energy Availability in Female Australian Rules Football Players

This study aimed to assess nutritional intake, sports nutrition knowledge and risk of Low Energy Availability (LEA) in female Australian rules football players. Victorian Football League Women’s competition (VFLW) players (n = 30) aged 18–35 (weight: 64.5 kg ± 8.0; height: 168.2 cm ± 7.6) were recruited from Victoria, Australia. Nutritional intake was quantified on training days using the Automated 24 h Dietary Assessment Tool (ASA24-Australia), and sports nutrition knowledge was measured by the 88-item Sports Nutrition Knowledge Questionnaire (SNKQ). The risk of LEA was assessed using the Low Energy Availability in Females Questionnaire (LEAF-Q). Daily mean carbohydrate intake in the current investigation was 3 g⋅kg⁻¹⋅d⁻¹, therefore, below the minimum carbohydrate recommendation for moderate exercise of approximately one hour per day (5–7 g⋅kg⁻¹⋅d⁻¹) and for moderate to intense exercise for 1–3 h per day (6–10 g⋅kg⁻¹⋅d⁻¹) for 96.3% and 100% of players, respectively. Daily mean protein intake was 1.5 g⋅kg⁻¹⋅d⁻¹, therefore, consistent with recommendations (1.2–2.0 g⋅kg⁻¹⋅d⁻¹) for 77.8% of players. Daily mean calcium intake was 924.8 mg⋅d⁻¹, therefore, below recommendations (1000 mg⋅d⁻¹) for 65.5% of players, while mean iron intake was 12.2 mg⋅d⁻¹, also below recommendations (18 mg⋅d⁻¹) for 100% of players. Players answered 54.5% of SNKQ questions correctly, with the lowest scores observed in the section on supplements. Risk of LEA was evident in 30% of players, with no differences in carbohydrate (p = 0.238), protein (p = 0.296), fat (p = 0.490) or energy (p = 0.971) intakes between players at risk of LEA and those not at risk. The results suggest that female Australian rules football players have an inadequate intake of carbohydrate and calcium and low sports nutrition knowledge. Further investigation to assess the risk of LEA using direct measures is required.

Impact of Eccentric or Concentric Training on Body Composition and Energy Expenditure

PURPOSE

To compare the effects of 8-wk eccentric (ECC) versus concentric (CON) training using downhill and uphill running in rats on whole body composition, bone mineral density (BMD), and energy expenditure.

METHODS

Animals were randomly assigned to one of the following groups: 1) control (CTRL), 2) +15% uphill-running slope (CON), 3) -15% downhill-running slope (ECC15), and 4) -30% downhill-running slope (ECC30). Those programs enabled to achieve conditions of isopower output for CON and ECC15 and of iso-oxygen uptake (V˙O2) for CON and ECC30. Trained rats ran 45 min at 15 m·min five times per week. Total body mass, fat body mass, and lean body mass (LBM) measured through EchoMRI™, and 24-h energy expenditure including basal metabolic rate (BMR) assessed using PhenoMaster/LabMaster™ cage system were obtained before and after training. At sacrifice, the right femur was collected for bone parameters analysis.

RESULTS

Although total body mass increased in all groups over the 8-wk period, almost no change occurred for fat body mass in exercised groups (CON, -4.8 ± 6.18 g; ECC15, 0.6 ± 3.32 g; ECC30, 2.6 ± 6.01 g). The gain in LBM was mainly seen for ECC15 (88.9 ± 6.85 g) and ECC30 (101.6 ± 11.07 g). ECC was also seen to positively affect BMD. An increase in BMR from baseline was seen in exercise groups (CON, 13.9 ± 4.13 kJ·d; ECC15, 11.6 ± 5.10 kJ·d; ECC30, 18.3 ± 4.33 kJ·d) but not in CTRL one. This difference disappeared when BMR was normalized for LBM.

CONCLUSIONS

Results indicate that for iso-V˙O2 training, the impact on LBM and BMD is enhanced with ECC as compared with CON, and that for isopower but lower V˙O2 ECC, an important stimulus for adaptation is still observed. This provides further insights for the use of ECC in populations with cardiorespiratory exercise limitations.

Normative fat-free mass index values for a diverse sample of collegiate female athletes

The purpose of this study was to establish normative fat-free mass index (FFMI) ranges in collegiate female athletes. A sample of 266 female athletes (Mean±SD; Age: 19.7 ± 1.5 yrs, Height: 166.0 ± 6.4 cm, Weight: 63.2 ± 8.8 kg) were included in analyses. Dual-energy X-ray absorptiometry measured bone mineral content (BMC; kg) and lean mass (LM; kg). Fat-free mass index was calculated as follows: FFMI = (BMC + LM)/Height². Participants were classified by sport: cross-country (XC), field hockey, football, gymnastics, lacrosse, resistance-trained, swimming track. Mean, range and percentile ranks of FFMI were calculated for the full sample for each cohort. For all females, mean FFMI was 16.9 ± 1.7 kg/m², FFMI values ranged from 13.3 to 25.5 kg/m². The XC athletes had the lowest FFMI (15.3 ± 0.96 kg/m²; p < 0.001). Mean FFMI measures were similar between all other female athletes. Percentile ranks varied across sport; median FFMI was highest for football (18.0 kg/m²), lowest for XC (15.1 kg/m²) and ranged between 16.4 and 17.3 kg/m² for all other athletes. Establishing sport-specific FFMI values for female athletes may be beneficial for athletes and coaches by leading to more appropriate body composition goals based on FFM.

Medical and Musculoskeletal Concerns for the Wheelchair Athlete: A Review of Preventative Strategies

Adaptive sports refers to organized sporting activities that are practiced by individuals with disabilities and are worthwhile to maintain physical and psychological health. As adaptive sports participation continues to rise, health care providers must have an enhanced understanding of injury and illness patterns specific to the adaptive athlete. Early recognition and prevention are important to ensure safe and successful participation in sport. The present review aims to provide a framework for diagnosis and prevention of common conditions specific to the wheelchair athlete. In particular, autonomic dysreflexia, impaired thermoregulation, urinary tract infection, and pressure injuries, as well as shoulder pain, upper-extremity entrapment neuropathies, and osteoporotic fractures will be discussed.

Association of Healthy Eating Index and oxidative stress in adolescent volleyball athletes and non-athletes

OBJECTIVES

The objective of this study was to compare the relationship between the Healthy Eating Index and oxidative stress parameters in adolescent athletes and non-athletes.

METHODS

A cross-sectional study was carried out with 18 adolescent male and female volleyball athletes who were paired with 15 adolescent non-athletes. Body fat percentage, food intake, free radical production, antioxidant enzyme activity, and thiol and protein damage were measured.

RESULTS

In the Healthy Eating Index assessment, the food quality of 72.7% of the sample was classified as low, and no participant was found to have good food quality. The mean intake of vitamins A and E was below recommendations in both groups and sexes; however vitamin C intake was appropriate for the age group. Increased free radical production was observed in the athletes' erythrocytes (p<0.001), accompanied by lower levels of plasma reduced glutathione (p = 0.01), but there were no correlations between Healthy Eating Index and oxidative stress parameters or between body composition, vitamin A, C and E intake and oxidative stress.

CONCLUSIONS

The sample's diet quality was classified as low and, despite the fact that there was greater production of free radicals in the athletes' erythrocytes and plasma, in addition to lower levels of plasma reduced glutathione , there was no correlation between Healthy Eating Index and oxidative stress.

Weight loss practice, nutritional status, bone health, and injury history: A profile of professional jockeys in Korea

[Purpose]

The purpose of this study was to investigate the impact of weight loss practices on nutritional status, bone health, and injury history among Korean professional jockeys.

[Methods]

Forty-three male jockeys completed a questionnaire to assess their weight loss practices. Of these, 10 jockeys were selected for in-depth assessment of their nutritional status, bone health, and injury history.

[Results]

The questionnaires revealed that 81.4% of jockeys lost weight every week mainly by dieting and/or exercising. None of the jockeys consumed enough food during the weight loss period. Two jockeys were diagnosed with osteopenia and one was diagnosed with osteoporosis. Only history of fracture showed a significant correlation with low bone mineral density. All jockeys had more than one injury experience throughout their career. Fracture was the most common type of injury, occurring during practice and/or competition and caused mainly by difficulties in handling the horses.

[Conclusion]

Professional jockeys in Korea use extreme weight loss methods. Their repeated periods of poor nutritional intake may result in seriously low bone mineral density, which may aggravate injuries sustained during horse races. Implementation of balanced dietary programs and delivery of health education on weight management are urgently required.

Predictive Factors for Vitamin D Concentrations in Swiss Athletes: A Cross-sectional Study

Vitamin D concentrations corresponding to 75 nmol/L 25(OH)D have been associated with maintained muscle function, growth and regeneration, optimal bone health and immunology in athletes. The objective of this study was to investigate the prevalence and predictors of insufficient 25(OH)D concentrations in athletes. Six hundred three Swiss athletes were assessed. 25(OH)D was analysed by high-performance liquid chromatography (HPLC). A standardized questionnaire was used to gather information about potential predictors for 25(OH)D concentrations; 50.5% showed insufficient 25(OH)D concentrations. Differences in predicted probability of insufficient 25(OH)D were found for those vitamin D supplemented (42%) versus not supplemented (52%), in those performing indoor (58%) versus outdoor sports (43%), and during the sun-deprived seasons of fall (49%), winter (70%) and spring (57%) compared with summer (17%). Higher BMI z-scores and age were associated with higher 25(OH)D concentrations. In conclusion, insufficient 25(OH)D concentrations were common among athletes especially at a younger age, among those not supplemented, in athletes who trained indoors, and during the sun-deprived seasons. Because the prevalence of insufficient 25(OH)D concentrations in this study was high, regular supplementation in athletes may be indicated, except perhaps during the summer season. Further research is needed to determine which 25(OH)D concentrations lead to optimal health and performance in athletes.

Identification of 613 new loci associated with heel bone mineral density and a polygenic risk score for bone mineral density, osteoporosis and fracture

Low bone mineral density (BMD) leads to osteoporosis, and is a risk factor for bone fractures, including stress fractures. Using data from UK Biobank, a genome-wide association study identified 1,362 independent SNPs that clustered into 899 loci of which 613 are new. These data were used to train a genetic algorithm using 22,886 SNPs as predictors and showing a correlation with heel bone mineral density of 0.415. Combining this genetic algorithm with height, weight, age and sex resulted in a correlation with heel bone mineral density of 0.496. Individuals with low scores (2.2% of total) showed a change in BMD of -1.16 T-score units, an increase in risk for osteoporosis of 17.4 fold and an increase in risk for fracture of 1.87 fold. Genetic predictors could assist in the identification of individuals at risk for osteoporosis or fractures.

Effectiveness of various isometric exercises at improving bone strength in cortical regions prone to distal tibial stress fractures

A computational model was used to compare the local bone strengthening effectiveness of various isometric exercises that may reduce the likelihood of distal tibial stress fractures. The developed model predicts local endosteal and periosteal cortical accretion and resorption based on relative local and global measures of the tibial stress state and its surface variation. Using a multisegment 3-dimensional leg model, tibia shape adaptations due to 33 combinations of hip, knee, and ankle joint angles and the direction of a single or sequential series of generated isometric resultant forces were predicted. The maximum stress at a common fracture-prone region in each optimized geometry was compared under likely stress fracture-inducing midstance jogging conditions. No direct correlations were found between stress reductions over an initially uniform circular hollow cylindrical geometry under these critical design conditions and the exercise-based sets of active muscles, joint angles, or individual muscle force and local stress magnitudes. Additionally, typically favorable increases in cross-sectional geometric measures did not guarantee stress decreases at these locations. Instead, tibial stress distributions under the exercise conditions best predicted strengthening ability. Exercises producing larger anterior distal stresses created optimized tibia shapes that better resisted the high midstance jogging bending stresses. Bent leg configurations generating anteriorly directed or inferiorly directed resultant forces created favorable adaptations. None of the studied loads produced by a straight leg was significantly advantageous. These predictions and the insight gained can provide preliminary guidance in the screening and development of targeted bone strengthening techniques for those susceptible to distal tibial stress fractures.

The effect of hormone therapy on bone mineral density and cardiovascular factors among Iranian female athletes with amenorrhea/oligomenorrhea: A randomized clinical trial

Background: Functional hypothalamic menstrual disorder (FHMD) has a destructive effect on the athlete's bone mineral density and cardiovascular system. Utilizing hormone replacement therapy to treat FHMD in athletes is controversial. This study was conducted to examine the effect of hormone therapy on bone density and the cardiovascular system of professional female athletes with FHMD. Methods: In this study, 18 female athletes with at least a 2- year history of FHMD were recruited in a 9-month single blind randomized clinical intervention (RCT) and randomly classified into 2 groups: the oral contraceptive pills (OCP) group, who received a lowdose combined oral contraceptive (OC) containing 30 µg ethinyl estradiol and 150 µg levonorgestrel (n= 10), and the control group (n= 8). Bone mineral densitometry (BMD) and certain cardiovascular risk factors were measured before and after the 9-month trial. The Chi square test was used to compare the quantitative and qualitative results. Results: Bone mineral density did not change significantly in either group. Very low density lipoprotein (VLDL) (p= 0.035) and Apolipoprotein B (Apo B) (p= 0.04) reduced significantly in the OCP group. An increase was observed in the serum levels of Apolipoprotein A (Apo A) (p= 0.01) in the control group. Changes in the Apo B to Apo A ratio was significant in both groups (OCP group: p= 0.018, control group: p= 0.040). No significant changes were observed in the other measured factors. Conclusion: Although the administration of estrogen did not significantly increase bone mineral density, it had positive effects on the cardiovascular system and lipid profile.

Nutritional Aspects of the Female Athlete

Athletes have specific needs based on sex, size, sport, exercise intensity, duration of activity, phase of training, and the season in which the sport is played. Nutritionally, the female athlete is unique, with needs that may vary based on hormonal fluctuations related to the menstrual cycle. This article provides an overview of the distinct nutritional needs and concerns of the physically active female, including energy availability, macronutrient needs, micronutrient needs, hydration, supplements, and other nutritional issues. Although there is some research focusing specifically on the female athlete and her exceptional nutritional concerns, further gender-specific exploration is needed in all areas.

The female athlete triad: special considerations for adolescent female athletes

The number of adolescent girls participating in sports has dramatically increased throughout the last few decades. In the early 1990's, an association between amenorrhea, osteoporosis, and disordered eating was recognized and eventually labeled the 'Female Athlete Triad'. In 1997, the Task Force on Women's Issues of American College of Sports Medicine (ACSM) published a position statement on this triad of conditions that were becoming increasingly more prevalent amongst female athletes. Initially, the 'Female Athlete Triad' was characterized by disordered eating, amenorrhea, and osteoporosis. However, as the number of adolescent female athletes has continued to grow, there has been further research and investigation into this field and the triad has evolved in definition. It is essential for all health care practitioners and other professionals who care for adolescent athletes to be attentive to the clinical signs, detection, evaluation, and management of the female athlete triad, as the sequelae can have a significant impact on the health and well-being of a young person both in the short and long-term.