Nutrition and Athlete Bone Health

Common questions and misconceptions about protein supplementation: what does the scientific evidence really show?

Protein supplementation often refers to increasing the intake of this particular macronutrient through dietary supplements in the form of powders, ready-to-drink shakes, and bars. The primary purpose of protein supplementation is to augment dietary protein intake, aiding individuals in meeting their protein requirements, especially when it may be challenging to do so through regular food (i.e. chicken, beef, fish, pork, etc.) sources alone. A large body of evidence shows that protein has an important role in exercising and sedentary individuals. A PubMed search of "protein and exercise performance" reveals thousands of publications. Despite the considerable volume of evidence, it is somewhat surprising that several persistent questions and misconceptions about protein exist. The following are addressed: 1) Is protein harmful to your kidneys? 2) Does consuming "excess" protein increase fat mass? 3) Can dietary protein have a harmful effect on bone health? 4) Can vegans and vegetarians consume enough protein to support training adaptations? 5) Is cheese or peanut butter a good protein source? 6) Does consuming meat (i.e., animal protein) cause unfavorable health outcomes? 7) Do you need protein if you are not physically active? 8) Do you need to consume protein ≤ 1 hour following resistance training sessions to create an anabolic environment in skeletal muscle? 9) Do endurance athletes need additional protein? 10) Does one need protein supplements to meet the daily requirements of exercise-trained individuals? 11) Is there a limit to how much protein one can consume in a single meal? To address these questions, we have conducted a thorough scientific assessment of the literature concerning protein supplementation.

An Opinion on the Interpretation of Bone Turnover Markers Following Acute Exercise or Nutrition Intervention and Considerations for Applied Research

It is important for athlete and public health that we continue to develop our understanding of the effects of exercise and nutrition on bone health. Bone turnover markers (BTMs) offer an opportunity to accelerate the progression of bone research by revealing a bone response to exercise and nutrition stimuli far more rapidly than current bone imaging techniques. However, the association between short-term change in the concentration of BTMs and long-term bone health remains ambiguous. Several other limitations also complicate the translation of acute BTM data to applied practice. Importantly, several incongruencies exist between the effects of exercise and nutrition stimuli on short-term change in BTM concentration compared with long-term bone structural outcomes to similar stimuli. There are many potential explanations for these inconsistencies, including that short-term study designs fail to encompass a full remodeling cycle. The current article presents the opinion that data from relatively acute studies measuring BTMs may not be able to reliably inform applied practice aiming to optimize bone health. There are important factors to consider when interpreting or translating BTM data and these are discussed.

Multivitamin Compliance Reduces Injuries of Female Recruits at Air Force Basic Training: A Randomized Controlled Cohort Study

INTRODUCTION

Department of the Air Force basic military training (BMT) is the 7.5-week initial entry training for all enlisting U.S. Air Force and Space Force recruits. Overuse musculoskeletal injuries (MSKI) during training threaten success in BMT, and trainees with nutritional deficiencies are at higher risk. Several efforts are made at BMT to mitigate these issues to help trainees graduate on time, such as the distribution of multivitamins (MVI) to female recruits. However, trainee compliance with the prescribed MVI has been reported to be low, calling into question the effectiveness of this intervention. This study evaluated the effect of briefing modality offered to these trainees at the time of distribution on educational effectiveness, MVI compliance, and injury rates.

MATERIALS AND METHODS

This was a randomized controlled cohort study of BMT female trainees. Subjects included all female trainees of a single iteration of BMT concurrently completing training within the same squadron. At the outset of training, cohorts were randomly educated in one of two ways regarding the provided MVI. The control cohort (n = 80) was presented with the standard educational video created by BMT-registered dietitians, while the test cohort (n = 79) was presented the video and then also briefed in-person by a group of subject matter experts. At the end of BMT, the trainees completed a questionnaire regarding their knowledge, confidence, and compliance with the MVI. Additionally, a routinely collected training database was queried and analyzed for differences in injuries and training outcomes using the chi-squared test with significance set to α ≤ 0.05.

RESULTS

Although both cohorts found their educational presentation useful, the "in-person" cohort reported significantly higher compliance rates and were found to be diagnosed with MSKI and bone stress injuries at significantly lower rates (43% and 66% relative risk reductions, respectively).

CONCLUSIONS

Education to female BMT trainees regarding the MVI, which included a face-to-face discussion with subject matter experts, resulted in greater compliance and reduced incidence of MSKI and bone stress injury, compared to a video prepared by registered dietitians alone. Such educational approaches should continue to be strived for in this and other military population health measures. This study's implication of MVI efficacy for injury risk reduction in female trainees should be further studied, verified, and improved upon in this and other populations.

LINC00963 Represses Osteogenic Differentiation of hBMSCs via the miR-10b-5p/RAP2A/AKT Axis

Osteogenic differentiation of human bone marrow-derived mesenchymal stem cells (hBMSCs) is important for human bone formation. Long non-coding RNAs (lncRNAs) are critical regulators in osteogenic differentiation. This study aimed to explore the function and mechanisms of long intergenic non-protein coding RNA 963 (LINC00963) in affecting osteogenesis. Cell differentiation was assessed by alkaline phosphatase (ALP) activity detection and ALP staining assay. Meanwhile, levels of osteogenic marker genes, including RUNX family transcription factor 2 (RUNX2), osteocalcin (OCN), and osteopontin (OPN), were detected by RT-qPCR and western blot. Cell proliferation and apoptosis were measured using CCK-8 assay and flow cytometry analysis. RNA immunoprecipitation (RIP), RNA pull-down and luciferase reporter assays were used to investigate the interaction between genes. LINC00963 expression was down-regulated in hBMSCs treated with osteogenic induction. LINC00963 overexpression inhibited hBMSCs differentiation, proliferation, and elevated apoptosis. LINC00963 acted as a competing endogenous RNA (ceRNA) to interact with miR-10b-5p and thereby regulated the expression level of Ras-related protein Rap-2a (RAP2A). LINC00963 regulated RAP2A to inhibit the level of phosphorylated AKT (p-AKT). LINC00963 inhibited hBMSCs differentiation, proliferation, and elevated apoptosis via the miR-10b-5p/RAP2A/AKT signaling, which might help improve the treatment of osteoporosis.

A literature review of biomarkers used for diagnosis of relative energy deficiency in sport

Introduction

The review aims to summarize the markers used in diagnosing relative energy deficiency in sport (REDs) and compare them with the REDs CAT2 score.

Methods

A systematic search was performed in the PubMed, Web of Science, and SPORTDiscus databases during April 2023. The descriptors used were "athlete" AND "REDs," along with respective entry terms. The selection process followed the PRISMA 2020 recommendations, identifying 593 records, from which 13 studies were ultimately selected. Seventy-nine markers were identified and categorized into six groups: bone mineral density (BMD), metabolic resting rate, blood biomarkers, anthropometrics, nutritional intake, and performance parameters. The most frequently utilized biomarkers included BMD, anthropometric parameters (e.g., body mass index, body mass, and fat mass), and the triiodothyronine (T3) concentration.

Results

According to the REDs CAT2 pointed indicators, the biomarkers varied among the studies, while 7 out of the 13 included studies achieved a ≥60% agreement rate with this tool. The prevalence of low energy availability, an etiological factor in the development of REDs, was detected in 4 out of 13 studies, with an average of 39.5%.

Conclusion

In conclusion, this review highlights the most commonly used markers in diagnosing REDs, such as BMD, anthropometric parameters, and T3 hormone concentration. Due to the current inconsistencies, standardizing diagnostic methodologies is crucial for future research. By focusing on widely used markers, this review aids future research planning and result interpretation and points out the ongoing need for methodological consistency in evolving diagnostic tools.

Systematic Review Registration

https://www.crd.york.ac.uk/, PROSPERO (CRD42022320007).

Running Event, Age, and Competitive Level as Predictors of Dual-Energy X-Ray Absorptiometry-Derived Body Composition and Bone Health Markers in Female Runners

ABSTRACT

Wilson, LJ and Curtis, C. Running event, age, and competitive level as predictors of dual-energy X-ray absorptiometry-derived body composition and bone health markers in female runners. J Strength Cond Res 38(7): e366-e372, 2024-The aim of this study was to assess the impact of running discipline, competitive level (COMP), and age on body composition measures in female athletes. A total of n = 51 female runners (age: 30.9 ± 5.7 years, stature: 166.7 ± 5.7 cm, and body mass (BM): 57.1 ± 8.2 kg) completed a full-body dual-energy x-ray absorptiometry (DXA) scan in a cross-sectional design. One-way ANOVA or Kruskal-Wallis was used to identify differences in DXA measures and independent variables. Stepwise regression determined the contribution of independent variables on DXA measures. Body fat percentage (BF%) and fat mass (FM) differed based on COMP (BF%: H (2) = 17.451; FM: H (2) = 17.406, both p ≤ 0.0001). Competitive level modestly predicted BF% and FM (BF%: R2adj = 0.316, F (1,50) = 22.660; FM: R2adj = 0.300, F (1,50) = 21.029, both p ≤ 0.0001). Bone mineral density (BMD) and BMD Z-score (BMD Z ) did not differ between age, running discipline, or COMP (age: BMD: F (2,50) = 2.825, BMD Z : F (2,50) = 2.215; running discipline: BMD: F (3,50) = 1.145, BMD Z : F (3,50) = 1.474; COMP: BMD: F (2,50) = 0.074, BMD Z : F (2,50) = 1.297, all p ≤ 0.05). Age and running discipline modestly predicted BMD and BMD Z (BMD: R2adj = 0.179, F (1,50) = 5.264; BMD Z : R2adj = 0.173, F (1,50) = 4.545, both p ≤ 0.05). These findings indicate COMP may be a predictor of BF% and FM. Age and running discipline appear predictors of bone health markers. Such findings may enable medical and sport science practitioners to tailor interventions relating to realization of training adaptations, performance, and health.

The Improvement and Related Mechanism of Microecologics on the Sports Performance and Post-Exercise Recovery of Athletes: A Narrative Review

The diversity and functionality of gut microbiota may play a crucial role in the function of human motor-related systems. In addition to traditional nutritional supplements, there is growing interest in microecologics due to their potential to enhance sports performance and facilitate post-exercise recovery by modulating the gut microecological environment. However, there is a lack of relevant reviews on this topic. This review provides a comprehensive overview of studies investigating the effects of various types of microecologics, such as probiotics, prebiotics, synbiotics, and postbiotics, on enhancing sports performance and facilitating post-exercise recovery by regulating energy metabolism, mitigating oxidative-stress-induced damage, modulating immune responses, and attenuating bone loss. Although further investigations are warranted to elucidate the underlying mechanisms through which microecologics exert their effects. In summary, this study aims to provide scientific evidence for the future development of microecologics in athletics.

National trends in nine key minerals intake (quantity and source) among U.S. adults, 1999 to march 2020

BACKGROUND

Changes in economy and dietary guidelines brought a great shock to diet quality and meal behaviors, but if these transformations have extended to minerals intake and their sources was still poorly understood. It is essential to evaluate time trends in minerals intake and their sources to inform policy makers.

OBJECTIVE

To investigate trends in minerals intake and their sources among U.S. adults.

METHODS

This analysis used dietary data collected by 24-h recalls from U.S. adults (≥ 20 years) in NHANES (1999-March 2020). Minerals intake, age-adjusted percentage of participants meeting recommendations, and minerals sources were calculated among all participants and by population subgroups in each NHANES survey cycle. Weighted linear or logistic regression models were used to examine the statistical significance of time trends.

RESULTS

A total of 48223 U.S. adults were included in this analysis. From 1999 to March 2020, intake of calcium (from 0.94 to 1.02 g/day), magnesium (from 308.07 to 321.85 mg/day), phosphorus (from 1.24 to 1.30 g/day), and sodium (from 3.24 to 3.26 mg/day) from food and beverages (FB) and dietary supplements (DSs) significantly increased, and intake of iron (from 19.17 to 16.38 mg/day), zinc (from 16.45 to 14.19 mg/day), copper (from 1.79 to 1.38 mg/day), and potassium (from 2.65 to 2.50 g/day) from FB + DSs decreased (all FDR < 0.05). Additionally, age-adjusted percentage of participants meeting recommendations for calcium, phosphorus, sodium, and selenium significantly increased, that for iron, potassium, zinc, and copper decreased (all FDR < 0.05). Minerals intake and time trends in minerals intake were highly variable depending on age, gender, race/ethnicity, education, and income. For example, white, higher socioeconomic status participants had a higher minerals intake (e.g. iron, zinc, and copper), but had a greater decrease in minerals intake. Furthermore, the percentage of minerals from milks and DSs decreased, and that from beverages increased.

CONCLUSION

From 1999 to March 2020, both minerals intake and their sources experienced a significant alteration among U.S. adults. Many differences in minerals intake and their food sources across sociodemographic characteristics appeared to narrow over time. Although some improvements were observed, important challenges, such as overconsumption of sodium and underconsumption of potassium, calcium, and magnesium, still remained among U.S. adults.

High-Protein Diets during either Resistance or Concurrent Training Have No Detrimental Effect on Bone Parameters in Resistance-Trained Males

BACKGROUND

The effects of combining resistance training (RT) and concurrent training (CT; resistance + endurance training) with varied protein doses on bone measures remain poorly understood. Hence, we conducted a comparison of the impacts of two high-protein diets (1.6 or 3.2 g kg-1 d-1) over 16 weeks in resistance-trained males, either with CT or RT alone.

METHODS

A total of forty-eight males, all of whom were resistance-trained, had the following demographics: 26.6 ± 6 years, body mass index: 25.6 ± 2.9 kg m-2 administered either 3.2 g kg-1 d-1 protein (CT2; n = 12; RT2; n = 12) or 1.6 g kg-1 d-1 protein (CT1; n = 12; RT1; n = 12) during 16 weeks (four sessions·w-1). Bone parameters were assessed pre- and post-intervention.

RESULTS

There was no significant interaction between the intervention group and time for the legs, arms, ribs, or pelvis area BMC and BMD (p > 0.05). For the BMD of the pelvis and the BMC of the right ribs, however, there were significant time effects noted (p < 0.05). Furthermore, there was a significant interaction between the intervention group and time in the lumbar and thoracic spines, with a particular time effect noted for the thoracic spine region (p < 0.05). The regional differences in skeletal responses to the intervention are highlighted by these data.

CONCLUSION

Our findings show that the intake of two high-protein diets combined with RT and CT during 16 weeks had no adverse effects on bone tissue parameters. While these findings indicate that protein intake between 2 and 3 times the current RDI does not promote bone demineralization when consumed in conjunction with exercise, future studies investigating the long-term effects of chronic high protein intake on bone tissue health are warranted.

Advancing athletic assessment by integrating conventional methods with cutting-edge biomedical technologies for comprehensive performance, wellness, and longevity insights

In modern athlete assessment, the integration of conventional biochemical and ergophysiologic monitoring with innovative methods like telomere analysis, genotyping/phenotypic profiling, and metabolomics has the potential to offer a comprehensive understanding of athletes' performance and potential longevity. Telomeres provide insights into cellular functioning, aging, and adaptation and elucidate the effects of training on cellular health. Genotype/phenotype analysis explores genetic variations associated with athletic performance, injury predisposition, and recovery needs, enabling personalization of training plans and interventions. Metabolomics especially focusing on low-molecular weight metabolites, reveal metabolic pathways and responses to exercise. Biochemical tests assess key biomarkers related to energy metabolism, inflammation, and recovery. Essential elements depict the micronutrient status of the individual, which is critical for optimal performance. Echocardiography provides detailed monitoring of cardiac structure and function, while burnout testing evaluates psychological stress, fatigue, and readiness for optimal performance. By integrating this scientific testing battery, a multidimensional understanding of athlete health status can be achieved, leading to personalized interventions in training, nutrition, supplementation, injury prevention, and mental wellness support. This scientifically rigorous approach hereby presented holds significant potential for improving athletic performance and longevity through evidence-based, individualized interventions, contributing to advances in the field of sports performance optimization.

The Association of nutritional status and physical activity on osteoporotic refractures among older adults

BACKGROUND

This paper focuses on revealing the relationship between the Geriatric Nutritional Risk Index (GNRI) and Activity of Daily Living (ADL) with osteoporotic refracture.

METHODS

Data from 1068 inpatients with osteoporotic fractures were analyzed. Binary logistic regression, Cox proportional hazard regression and Kaplan-Meier curves were performed for osteoporosis characteristics and its risk factors. Receiver operating characteristic (ROC) curve was developed to predict the cut-off value.

RESULTS

The study showed that older age, lower ADL and lower GNRI were independent risk factors for osteoporotic fracture with OR of 1.039, 0.946, 0.892 and HR of 1.033, 0.967, 0.947 respectively. According to the results of ROC, the predictive accuracy of GNRI was high with an area under ROC (AUC) of 0.715, sensitivity of 76.6%, specificity of 53.5% and a threshold value of 99.65.

CONCLUSION

Older age, lower ADL and lower GNRI were independent risk factors for osteoporotic refracture.

High prevalence of low bone mineral density but normal trabecular bone score in Norwegian elite Para athletes

Background

Low bone mineral density (BMD) increases the risk of bone stress injuries (BSI) and is one of several clinical concerns in Para athlete sports medicine. However, whether bone microarchitecture is altered in Para athletes is not known.

Objective

We aimed to investigate BMD, bone microarchitecture and incidence of bone stress injuries in Norwegian elite Para athletes.

Design

In this cross-sectional study in Para athletes, Dual energy x-ray absorptiometry (iDXA, Lunar, GE Health Care) derived areal BMD, trabecular bone score (TBS), a surrogate marker for bone microarchitecture, and body composition (body weight (BW), lean body mass (LBM), fat mass (FM), fat percentage) were investigated and compared between ambulant and non-ambulant athletes. Also, the association between BMD, TBS and body composition variables was investigated. Incidence of BSI was assessed with a questionnaire and confirmed by a sports physician in a clinical interview. BMD Z-score <-1 was defined as low and ≤-2 as osteoporotic. TBS ≥ 1.31 was normal, 1.23-1.31 intermediate and <1.23 low.

Results

Among 38 athletes (26 ± 6 yrs, 14 females), BMD Z-score was low in 19 athletes, and osteoporotic in 11 athletes' lumbar spine (LS) or femoral neck (FN). BMD was lower in non-ambulant vs. ambulant athletes both in LS (1.13 ± 0.19 vs. 1.25 ± 0.14 g/cm2, p = 0.030) and FN (0.90 ± 0.15 vs. 1.07 ± 0.16 g/cm2, p = 0.003). TBS was normal for all athletes. BMD Z-score in LS was positively associated with TBS (r = 0.408, p = 0.013), body weight (r = 0.326, p = 0.046) and lean body mass (r = 0.414, p = 0.010), but not with fat mass or fat percentage. None of the athletes reported any BSI.

Conclusions

Half of the Norwegian elite Para athletes had low BMD, and 29% had BMD Z-score <-2 suggesting osteoporosis. Non-ambulant athletes were more prone to low BMD than ambulant athletes. However, despite high prevalence of low BMD, TBS was normal in all athletes, and BSI was absent in this young population.

A review on therapeutic mechanism of medicinal plants against osteoporosis: effects of phytoconstituents

Osteoporosis is a metabolic bone disorder that over time results in bone loss and raises the risk of fracture. The condition is frequently silent and only becomes apparent when fractures develop. Osteoporosis is treated with pharmacotherapy as well as non-pharmacological therapies such as mineral supplements, lifestyle changes, and exercise routines. Herbal medicine is frequently used in clinical procedures because of its low risk of adverse effects and cost-effective therapeutic results. In the current review, we have used a thorough strategy to identify some known medicinal plants with anti-osteoporosis capabilities, their origin, active ingredients, and pharmacological information. Furthermore, several signaling pathways, such as the apoptotic pathway, transcription factors, the Wnt/-catenin signaling pathway, and others, are regulated by bioactive components and help to improve bone homeostasis. This review will provide a better understanding of the anti-osteoporotic effects of bioactive components and the concomitant modulations of signaling pathways.

One Season in Professional Cycling Is Enough to Negatively Affect Bone Health

Cycling is a very popular sport worldwide, and several studies have already indicated that cycling at various levels has a negative impact on bone health. This is of concern to both performance and health managers of many cycling teams at different levels because of its economic and social impact. Based on the scientific literature, we hypothesize that a single season at the professional level can negatively affect bone health status. The aim of this study was to assess how professional cycling affects bone health markers after one season. Densitometry was used to measure the bone mineral density (BMD), bone mineral content (BMC), bone area (BA), fat mass (FM), fat-free mass (FFM), T-score and Z-score in professional cyclists after one season. After one season at the professional level, cyclists' BMD decreased significantly in the legs, trunk, ribs and pelvis (p ≤ 0.05). BMC decreased in the arms and spine (p ≤ 0.05). BA decreased significantly in the arms and spine (p ≤ 0.05). In addition, a significant decrease in Z-score (p ≤ 0.05) and a decreasing trend in T-score and total BMD (p = 0.06) were observed. One season of professional cycling is enough to negatively affect bone health status.

Bone Health in Young Athletes: a Narrative Review of the Recent Literature

PURPOSE OF REVIEW

The aim of this review is to discuss the most recent published scientific evidence regarding bone health in the pediatric athlete.

RECENT FINDINGS

Pediatric athletes commonly suffer from overuse injuries to the physes and apophyses, as well as bone stress injuries, for which magnetic resonance imaging grading of the severity of injuries may be useful in guiding return to sport. Adolescent athletes, particularly those who train indoors and during the winter season, are at risk for vitamin D deficiency, which has important implications for bone mineral density. However, the relationship between vitamin D status and traumatic fracture risk is still unclear. While the female athlete triad is a well-established condition, the current work has led to the recognition of parallel pathophysiology in male athletes, referred to as the male athlete triad. Recent evidence suggests that transdermal 17β-estradiol treatment in amenorrhoeic female athletes is an effective adjunctive treatment to improve bone mineral density in treatment of the female athlete triad. Young athletes are at risk for musculoskeletal injuries unique to the growing skeleton. Optimizing nutritional intake, particularly related to adequate vitamin D intake and prevention of the athlete triad, is critical to optimize bone health in the young athlete.

Effect of body composition on the athletic performance of soccer referees

Nutrition plays an important role in improving sports performance. The present study aimed at nutritional assessment and examined the relationship between athletic performance and body composition in soccer referees at different levels. The study participants were 120 male soccer referees. 5, 10 and 30 metres (m) sprint tests to measure speed and cooper test for physical fitness were applied in the referees. Participants were divided into two groups as city and class soccer referee. The anthropometric measurements, excluding fat mass (FM) (%), were higher in class referees. Fat mass (%) differences (14⋅1 ± 4⋅28 v. 12⋅3 ± 4⋅41) were statistically significant (P < 0⋅05). Daily energy and nutrient intakes were similar. The inadequacy percentages of energy, vitamin A and calcium were the highest (29⋅2, 30⋅0 and 34⋅2 %, respectively). It was found that a negative significant correlation between FM% and cooper test score (P < 0⋅01; r = -0⋅35), a positive significant correlation between FM% and 5, 10 and 30 m sprint test scores (P < 0⋅01, r = 0⋅38; P < 0⋅01, r = 0⋅38 and P < 0⋅01, r = 0⋅48, respectively). Similarly, there was a negative significant correlation between waist circumference (WC) and cooper test score (P < 0⋅01; r = -0⋅31), a positive significant correlation between WC and 5, 10 and 30 m sprint test scores (P < 0⋅01, r = 0⋅33; P < 0⋅01, r = 0⋅40; P < 0⋅01, r = 0⋅33, respectively). Nutritional recommendations for soccer referees should be made specific to the individual, considering body composition, training intensity and match frequency by a dietician.

Exploring the Relationship between Micronutrients and Athletic Performance: A Comprehensive Scientific Systematic Review of the Literature in Sports Medicine

The aim of this systematic review is twofold: (i) to examine the effects of micronutrient intake on athletic performance and (ii) to determine the specific micronutrients, such as vitamins, minerals, and antioxidants, that offer the most significant enhancements in terms of athletic performance, with the goal of providing guidance to athletes and coaches in optimizing their nutritional strategies. The study conducted a systematic search of electronic databases (i.e., PubMed, Web of Science, Scopus) using keywords pertaining to micronutrients, athletic performance, and exercise. The search involved particular criteria of studies published in English between 1950 and 2023. The findings suggest that vitamins and minerals are crucial for an athlete's health and physical performance, and no single micronutrient is more important than others. Micronutrients are necessary for optimal metabolic body's functions such as energy production, muscle growth, and recovery, which are all important for sport performance. Meeting the daily intake requirement of micronutrients is essential for athletes, and while a balanced diet that includes healthy lean protein sources, whole grains, fruits, and vegetables is generally sufficient, athletes who are unable to meet their micronutrient needs due to malabsorption or specific deficiencies may benefit from taking multivitamin supplements. However, athletes should only take micronutrient supplements with the consultation of a specialized physician or nutritionist and avoid taking them without confirming a deficiency.

Bone turnover following high-impact exercise is not modulated by collagen supplementation in young men: A randomized cross-over trial

INTRODUCTION

We assessed whether collagen supplementation augments the effects of high-impact exercise on bone turnover and whether a higher exercise frequency results in a greater benefit for bone metabolism.

METHODS

In this randomized, cross-over trial, 14 healthy males (age 24 ± 4 y, BMI 22.0 ± 2.1 kg/m²) performed 5-min of high-impact exercise once (JUMP+PLA and JUMP+COL) or twice daily (JUMP2+COL2) during a 3-day intervention period, separated by a 10-day wash out period. One hour before every exercise bout participants ingested 20 g hydrolysed collagen (JUMP+COL and JUMP2+COL2) or a placebo control (JUMP+PLA). Blood markers of bone formation (P1NP) and resorption (CTXI) were assessed in the fasted state before the ingestion of the initial test drinks and 24, 48, and 72 h thereafter. In JUMP+PLA and JUMP+COL, additional blood samples were collected in the postprandial state at 1, 2, 3, 4, 5 and 13 h after ingestion of the test drink.

RESULTS

In the postprandial state, serum P1NP concentrations decreased marginally from 99 ± 37 to 93 ± 33 ng/mL in JUMP+COL, and from 97 ± 32 to 92 ± 31 ng/mL in JUMP+PLA, with P1NP levels having returned to baseline levels after 13 h (time-effect, P = 0.053). No differences in serum P1NP concentrations were observed between JUMP+PLA and JUMP+COL (time x treatment, P = 0.58). Serum CTX-I concentrations showed a ~ 50 % decline (time, P < 0.001) in the postprandial state in JUMP+COL (0.9 ± 0.3 to 0.4 ± 0.2 ng/mL) and JUMP+PLA (0.9 ± 0.3 to 0.4 ± 0.2 ng/mL), with no differences between treatments (time x treatment, P = 0.17). Fasted serum P1NP concentrations increased ~8 % by daily jumping exercise (time-effect, P < 0.01), with no differences between treatments (time x treatment, P = 0.71). Fasted serum CTX-I concentrations did not change over time (time-effect, P = 0.41) and did not differ between treatments (time x treatment, P = 0.58).

CONCLUSIONS

Five minutes of high-impact exercise performed daily stimulates bone formation during a 3-day intervention period. This was indicated by an increase in fasted serum P1NP concentrations, rather than an acute increase in post-exercise serum P1NP concentrations. Collagen supplementation or an increase in exercise frequency does not further increase serum P1NP concentrations. The bone resorption marker CTX-I was not affected by daily short-duration high-impact exercise with or without concurrent collagen supplementation.

Impact of COVID-19 pandemic on cross-country runners: changes in training, sleep, diet, and mental health

Objective: Determine the impact of the COVID-19 pandemic on the changes in training, sleep, diet, and mental health of cross-country runners. Participants: Cross-country runners from NCAA Division II institutes. Methods: Wilcoxon signed-rank test was performed to analyze survey responses to ordinal questions on the survey while Spearman's rank correlation analysis (ρ) was used to calculate correlation between after the start of pandemic questions. Data was marked significant at p < 0.05. Results: Analysis of the survey responses revealed that cross-country runners were more likely to experience feelings of depression (p < 0.001), lack of motivation (p < 0.001), and higher daily stress (p < 0.001) after the start of the pandemic. After the start of the pandemic, runners running less days per week were more likely to report an increased feeling of depression (ρ=-0.315, p = 0.008) and lack of motivation (ρ=-0.458, p < 0.001). Conclusions: The present study underscores the importance of training, sleep, diet, and mental health amongst cross-country runners.

The Impact of Acute Calcium Intake on Bone Turnover Markers during a Training Day in Elite Male Rowers

INTRODUCTION

Although an acute exercise session typically increases bone turnover markers (BTM), the impact of subsequent sessions and the interaction with preexercise calcium intake remain unclear despite the application to the "real-life" training of many competitive athletes.

METHODS

Using a randomized crossover design, elite male rowers ( n = 16) completed two trials, a week apart, consisting of two 90-min rowing ergometer sessions (EX1, EX2) separated by 150 min. Before each trial, participants consumed a high (CAL; ~1000 mg) or isocaloric low (CON; <10 mg) calcium meal. Biochemical markers including parathyroid hormone (PTH), serum ionized calcium (iCa) and BTMs (C-terminal telopeptide of type I collagen, osteocalcin) were monitored from baseline to 3 h after EX2.

RESULTS

Although each session caused perturbances of serum iCa, CAL maintained calcium concentrations above those of CON for most time points, 4.5% and 2.4% higher after EX1 and EX2, respectively. The decrease in iCa in CON was associated with an elevation of blood PTH ( P < 0.05) and C-terminal telopeptide of type I collagen ( P < 0.0001) over this period of repeated training sessions and their recovery, particularly during and after EX2. Preexercise intake of calcium-rich foods lowered BTM over the course of a day with several training sessions.

CONCLUSIONS

Preexercise intake of a calcium-rich meal before training sessions undertaken within the same day had a cumulative and prolonged effect on the stabilization of blood iCa during exercise. In turn, this reduced the postexercise PTH response, potentially attenuating the increase in markers of bone resorption. Such practical strategies may be integrated into the athlete's overall sports nutrition plan, with the potential to safeguard long-term bone health and reduce the risk of bone stress injuries.

Positive association of lean mass and negative association of protein intake on bone mass and bone geometry of adolescent soccer players

OBJECTIVE

The aim of this study was to evaluate the association of food consumption and body composition on bone parameters in adolescent soccer players.

METHODS

There were 148 male soccer players 12 to 18 y who participated in the study. Body composition was assessed by dual energy x-ray absorptiometry, comprising bone mineral density (BMD) and bone mineral content (BMC) of total body without head (TBLH), lumbar spine (L1-L4), and right femoral neck (RFN). The bone geometry variables measured were femoral strength index (FSI), buckling ratio (BR), section modulus (Z), cross-sectional moment of inertia (CSMI), and cross-sectional area (CSA). Food intake was analyzed using the 24-h food recall. Somatic maturation was estimated by the peak height velocity equation. For the statistical analysis, the stepwise multiple linear regression was used, with P < 0.05.

RESULTS

Regarding food consumption, there was a high protein intake and low calcium intake. Lean mass was a predictor of BMC of TBLH (R² = 0.524), L1-L4 (R² = 0.492), and RFN (R² = 0.405); BMD of L1-L4 (R² = 0.407) and RFN (R² = 0.27); Z (R² = 0.683), CSMI (R² = 0.630), and CSA (R² = 0.640). There was a negative correlation between protein intake with bone mass and bone geometry parameters.

CONCLUSION

In adolescent soccer players, lean mass was a predictor of bone parameters, and high protein intake was negatively associated with bone mass and geometry.

Load carriage aerobic exercise stimulates a transient rise in biochemical markers of bone formation and resorption

Exercise can be both anabolic and catabolic for bone tissue. The temporal response of both bone formation and resorption following an acute bout of exercise is not well described. We assayed biochemical markers of bone and calcium metabolism for up to 3 days after military-relevant exercise. In randomized order, male (n = 18) and female (n = 2) Soldiers (means ± SD; 21.2 ± 4.1 years) performed a 60-min bout of load carriage (30% body mass; 22.4 ± 3.7 kg) treadmill exercise (EXER) or a resting control trial (REST). Blood samples were collected following provision of a standardized breakfast before (PRE), after (POST) exercise/rest, 1 h, 2 h, and 4 h into recovery. Fasted samples were also collected at 0630 on EXER and REST and for the next three mornings after EXER. Parathyroid hormone and phosphorus were elevated (208% and 128% of PRE, respectively, P < 0.05), and ionized calcium reduced (88% of PRE, P < 0.05) after EXER. N-terminal propeptide of type 1 collagen was elevated at POST (111% of PRE, P < 0.05), and the resorption marker, C-terminal propeptide of type 1 collagen was elevated at 1 h (153% of PRE, P < 0.05). Osteocalcin was higher than PRE at 1 through 4 h post EXER (119%-120% of PRE, P < 0.05). Sclerostin and Dickkopf-related protein-1 were elevated only at POST (132% and 121% of PRE, respectively, P < 0.05) during EXER. Trivial changes in biomarkers during successive recovery days were observed. These results suggest that 60 min of load carriage exercise elicits transient increases in bone formation and resorption that return to pre-exercise concentrations within 24 h post-exercise.NEW & NOTEWORTHY In this study, we demonstrated evidence for increases in both bone formation and resorption in the first 4 h after a bout of load carriage exercise. However, these changes largely disappear by 24 h after exercise. Acute formation and resorption of bone following exercise may reflect distinct physiological mechanoadaptive responses. Future work is needed to identify ways to promote acute post-exercise bone formation and minimize post-exercise resorption to optimize bone adaptation to exercise.

Quantitative Diet, Body Composition and Sprint Performance in Female Professional Beach Handball Players

Women's elite sports have experienced an exponential increase in the last decade, as has beach handball (BH). The high demands of this sport mean that athletes need to be in superior physical condition, so nutrition and body composition are determining factors in their sporting performance. For this reason, the aim of this study was to analyze, compare and correlate the most relevant variables of food intake (quantitative), body composition (focus on the bone mass characteristics) and sprint performance in female professional BH players. Thirty-three women from the National Spanish Team participated in this study. Dietary assessment, anthropometric measurements and sprint tests were performed. In general, the players had a low carbohydrate intake and adequate protein intake, with no significant differences depending on the category and playing position. For senior players, positive correlations were found between protein intake and bone mass (r = 0.584, p = 0.022), polyunsaturated fatty acid intake and muscle mass (r = 0.387, p = 0.026) and finally between fat mass and animal protein intake (r = 0.569, p = 0.027). Body composition was similar in both categories; however, goalkeepers had the highest fat (22.6 ± 3.86%, 16.2 ± 4.84 kg) component (vs. wings: 17.4 ± 3.53%, p = 0.031/vs. specialists: 11.1 ± 1.91 kg, p = 0.034), and senior players had higher muscle mass (kilograms). It is worth noting the finding that players with a greater trochanter height had significantly lower sprint times (p = 0.014 and p = 0.048 for 5 and 10 m, respectively). Certain bone characteristics, such as iliospinale height, biacromial and bimalleolar diameters, mesosternal perimeter and biceps skinfold, differ depending on the position. In addition, the greater speed of the senior players may be due to the greater specialization, number of training sessions performed and specific bone characteristics, such as trochanter height. In this regard, the data provided in this study will assist with establishing criteria for the selection of talent for this sporting discipline.

Fitness Soccer Athletes Training at the University of Limpopo, South Africa: Are the Macronutrients Intake and Anthropometric Status of These Athletes Optimal?

BACKGROUND

Dietary practices of the University of Limpopo soccer team athletes have been reported. However, the practices of those engaging in soccer for general fitness from different non-competitive teams remain unknown. To respond to this gap, the researchers investigated the energy, macronutrient intake, and BMI status and further correlated the two variables of the fitness non-competitive soccer athletes registered at the University of Limpopo in South Africa.

METHOD

A quantitative study design was undertaken to conveniently sample 60 out of 90 fitness soccer athletes from the four non-competitive soccer teams at the University of Limpopo sports grounds. Ethics approval was obtained from the University of Limpopo Research and Ethics Committee, and permission was given by the university sports management and team coaches. Athletes signed the informed consent form before participating in the study. Data were collected at the soccer fields during the afternoons before the start of training. Macronutrient intake data were collected using multiple (two) 24-h recall questionnaires on different days, which were validated by the food frequency questionnaire. Weight and height were measured using a digital scale (Seca 813 electronic flat scale) and stadiometer (Seca 213 portable stadiometer) for BMI calculations, respectively. The average energy and macronutrient intakes were calculated through the SAMRC FoodFinder software (3.0). The nutrient averages, together with the BMI results, were loaded into SPSS (26.0) for further analysis. Descriptive statistics were used to report the energy, macronutrient intake, and BMI statuses of athletes using percentages, means, and standard deviations (±SD). A one-way ANOVA test was used to determine the association between the latter variables. A p-value of ≤ 0.05 was the criterion used to correlate the variables.

RESULTS

All (100%) athletes were males, most of whom played soccer for 2-3 years while at the university. Almost half (48%) of athletes consumed energy (39.6 kcal/kg) below the recommendations. About 92% and 53% of athletes consumed carbohydrates (5.0 g/kg) and fat (1.2 g/kg) below the recommended values; while 43% consumed protein (1.4 g/kg) optimally. The majority (>80%) had a normal BMI (21.6 ± 2.6 kg/m²) status. However, there were no relationships between the energy (p = 0.383), CHO (p = 0.261), protein (p = 0.543), and fat (p = 0179) intake and the BMI status of athletes.

CONCLUSION

The macronutrient intake of fitness soccer athletes at the University of Limpopo is, on the whole, suboptimal. However, the athletes had normal body weights. There was no association between both the energy and macronutrient intake and the anthropometric (BMI) status of soccer athletes.

Short-Term Carbohydrate Restriction Impairs Bone Formation at Rest and During Prolonged Exercise to a Greater Degree than Low Energy Availability

Bone stress injuries are common in athletes, resulting in time lost from training and competition. Diets that are low in energy availability have been associated with increased circulating bone resorption and reduced bone formation markers, particularly in response to prolonged exercise. However, studies have not separated the effects of low energy availability per se from the associated reduction in carbohydrate availability. The current study aimed to compare the effects of these two restricted states directly. In a parallel group design, 28 elite racewalkers completed two 6-day phases. In the Baseline phase, all athletes adhered to a high carbohydrate/high energy availability diet (CON). During the Adaptation phase, athletes were allocated to one of three dietary groups: CON, low carbohydrate/high fat with high energy availability (LCHF), or low energy availability (LEA). At the end of each phase, a 25-km racewalk was completed, with venous blood taken fasted, pre-exercise, and 0, 1, 3 hours postexercise to measure carboxyterminal telopeptide (CTX), procollagen-1 N-terminal peptide (P1NP), and osteocalcin (carboxylated, gla-OC; undercarboxylated, glu-OC). Following Adaptation, LCHF showed decreased fasted P1NP (~26%; p < 0.0001, d = 3.6), gla-OC (~22%; p = 0.01, d = 1.8), and glu-OC (~41%; p = 0.004, d = 2.1), which were all significantly different from CON (p < 0.01), whereas LEA demonstrated significant, but smaller, reductions in fasted P1NP (~14%; p = 0.02, d = 1.7) and glu-OC (~24%; p = 0.049, d = 1.4). Both LCHF (p = 0.008, d = 1.9) and LEA (p = 0.01, d = 1.7) had significantly higher CTX pre-exercise to 3 hours post-exercise but only LCHF showed lower P1NP concentrations (p < 0.0001, d = 3.2). All markers remained unchanged from Baseline in CON. Short-term carbohydrate restriction appears to result in reduced bone formation markers at rest and during exercise with further exercise-related increases in a marker of bone resorption. Bone formation markers during exercise seem to be maintained with LEA although resorption increased. In contrast, nutritional support with adequate energy and carbohydrate appears to reduce unfavorable bone turnover responses to exercise in elite endurance athletes. © 2022 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

The association between sport nutrition knowledge, nutritional intake, energy availability, and training characteristics with the risk of an eating disorder amongst highly trained competitive road cyclists

Purpose

To determine the association between sport nutrition knowledge, nutritional intake, energy availability, and training characteristics with the risk of an eating disorder amongst highly trained competitive cyclists.

Methods

Using an observational cohort study design, 36 male cyclists (age = 23.1 ± 3.9 years) provided information on personal characteristics, training history and functional threshold power. The cyclists completed the sports nutrition knowledge questionnaire (SNKQ) and brief eating disorder in athletes questionnaire (BEDA-Q) before submitting a three-day food diary to quantify energy and macronutrient intake, and calculate energy availability.

Results

The estimated lean body mass, years training, weekly on-bike training and functional threshold power were 57.6 ± 3.9 kg, 5.9 ± 3.0 years, 16.4 ± 3.2 h and 355 ± 33 W, respectively. The mean score for the SNKQ was 60.0 ± 8.4% whilst the BEDA-Q score was 4.3 ± 4.1 AU. Training and rest day energy availability was 16 ± 18 kcal·kg eLBM−1 and 44 ± 14 kcal·kg eLBM−1, respectively. Associations between SNKQ with energy intake (r = 0.13, P = 0.553) and availability (r = 0.21, P = 0.345) were trivial to small. There was a large, negative association between SNKQ and BEDA-Q (r = –0.55, P = 0.006) suggesting that for every correct answer on the SNKQ, the BEDA-Q score reduced by 0.3 AU. All other association with the BEDA-Q were trivial to small (r = –0.29–0.27, all P > 0.05).

Conclusion

The results indicate that sport nutrition knowledge and energy intake was insufficient to match their training demand on training days. The large, negative association between SNKQ and BEDA-Q suggests that those highly trained cyclists with less sport nutrition knowledge may be at a greater risk of an eating disorder.

Female Athlete Triad and Male Athlete Triad Syndrome Induced by Low Energy Availability: An Animal Model

Energy availability (EA) is defined the difference in energy intake and exercise energy expenditure. Reduction of EA (i.e. Low energy availability, LEA) often causes abnormalities of reproduction system and drastic bone loss in some female athletes, the phenomenon is called as female athlete triad. More than ever before, it is considered a serious problem, the reason of these are (1) the syndrome occurred in female athletes but also male athletes, (2) LEA is leads to dysfunction of various organs other than reproductive system (Relative energy deficiency in sport, RED-S). On the other hand, we have focused on this syndrome and have proposed novel insights into the physiological effects of LEA on bone and solutions through nutritional treatment by recreating it in animal models. In this review, we will summarize the epidemiological and physiological perspectives of these diseases from historical background to recent findings, and introduce the usefulness of using animal models to explore mechanisms and treatments.

Associations of the Geriatric Nutritional Risk Index With Femur Bone Mineral Density and Osteoporosis in American Postmenopausal Women: Data From the National Health and Nutrition Examination Survey

Background

The geriatric nutritional risk index (GNRI) has been used as a significant tool to access the nutritional status of the elderly. However, the relationship between the GNRI and femur bone mineral density (BMD) and the risk of osteoporosis remains unclear in American postmenopausal women.

Objectives

We aimed to explore associations between the GNRI with femur BMD and the risk of osteoporosis in American postmenopausal women.

Methods

We merged the continuous National Health and Nutrition Examination Survey (NHANES) 2005–2006, 2007–2008, 2009–2010, 2013–2014, and 2017–2018 to ensure a large and representative sample, including 3,152 participants. The linear relationship between the GNRI and femur BMD was assessed via a weighted multivariate linear regression model. The odds ratios (ORs) and 95% confidence intervals (95% CIs) for the association between the GNRI and the risk of osteoporosis were assessed by a weighted logistic regression model. Moreover, the nonlinear relationship was also characterized by smooth curve fitting (SCF) and a weighted generalized additive model (GAM).

Results

After adjusting for all covariates, the weighted multivariable linear regression models demonstrated that the GNRI was positively correlated with femur BMD. The weighted logistic regression models demonstrated that each unit of increased GNRI value was associated with a decreased risk of osteoporosis of 4.13%. When categorizing GNRI based on quartiles, ORs between the risk of osteoporosis and the GNRI across quintiles 2, 3, and 4 compared with quintile 1 were 0.5565 (95% CI: 0.4791, 0.6463; P &lt; 0.000001), 0.5580 (95% CI: 0.4600, 0.6769; P &lt; 0.000001), and 0.3475 (95% CI: 0.2681, 0.4505; P &lt; 0.000001). The trends similar to the above were also observed in SCF and GAM.

Conclusion

This study indicated that nutritional status, represented by the GNRI, was positively associated with femur BMD and negatively associated with the risk of osteoporosis in American postmenopausal women. The GNRI may be a good tool to identify American postmenopausal women who need further bone health nutritional support.

Functional Properties of Meat in Athletes' Performance and Recovery

Physical activity (PA) and sport play an essential role in promoting body development and maintaining optimal health status both in the short and long term. Despite the benefits, a long-lasting heavy training can promote several detrimental physiological changes, including transitory immune system malfunction, increased inflammation, and oxidative stress, which manifest as exercise-induced muscle damages (EIMDs). Meat and derived products represent a very good source of bioactive molecules such as proteins, lipids, amino acids, vitamins, and minerals. Bioactive molecules represent dietary compounds that can interact with one or more components of live tissue, resulting in a wide range of possible health consequences such as immune-modulating, antihypertensive, antimicrobial, and antioxidative activities. The health benefits of meat have been well established and have been extensively reviewed elsewhere, although a growing number of studies found a significant positive effect of meat molecules on exercise performance and recovery of muscle function. Based on the limited research, meat could be an effective post-exercise food that results in favorable muscle protein synthesis and metabolic performance.

Nutritional recommendations for patients undergoing prolonged glucocorticoid therapy

Glucocorticoid (GC) therapy is a common treatment used in rheumatic and autoimmune diseases, owing to its anti-inflammatory and immunosuppressive effects. However, GC therapy can also induce a number of adverse effects, including muscle and bone loss, hypertension, metabolic perturbations and increased visceral adiposity. We review available evidence in this area and provide nutritional recommendations that might ameliorate these adverse effects. Briefly, optimizing calcium, vitamin D, sodium and protein intake and increasing consumption of unprocessed and minimally processed foods, while decreasing the consumption of ultra-processed foods, might counteract some of the specific challenges faced by these patients. Importantly, we identify a dearth of empirical data on how nutritional intervention might impact health-related outcomes in this population. Further research is required to investigate the clinical and therapeutic efficacy of these theory-based recommendations.

Bone health and asymmetry in elite female cricketers

The aim of this study is to determine if bone mineral density (BMD) and bone asymmetry differs between female cricket fast bowlers, spin bowlers and batters. BMD was determined at the total body, lumbar spine, and proximal femurs in 12 fast bowlers, 13 batters and 11 spin bowlers from pre-season DXA scans. High Z-scores at the total body, lumbar spine, and proximal femur were observed in all cricketers (mean Z-scores: +1.4 to +3.3) compared with a general age matched reference population. Fast bowlers had significantly greater BMD on the contralateral side of the lumbar spine compared with the ipsilateral side (p = 0.001, 5.9 - 12.1%). No asymmetry was found between hips in all groups. All cricket positions demonstrated high BMD at all measured sites. The lumbar spine of fast bowlers is asymmetric, with significantly greater BMD on the contralateral side of the spine, particularly at L4, possibly in response to the asymmetric lumbar loading patterns observed in bowling.HIGHLIGHTS Elite female cricketers demonstrate high BMD at total body, lumbar spine and proximal femur sites, regardless of playing position compared with a general age and ethnic group matched reference populationFast bowlers have greater BMD on the contralateral (opposite bowling arm) side of the lumbar spine compared with the ipsilateral side, while a symmetrical pattern was observed in spin bowlers and batters.No asymmetry in BMD or section modulus between hips was observed at any proximal femur site for any cricket position.

Body Composition and Bone Health Status of Jockeys: Current Findings, Assessment Methods and Classification Criteria

Jockeys are unlike other weight-making athletes as the sport of horse racing requires strict weight management to meet the racing stipulations, protracted working hours and an extended racing season with limited downtime. Several studies have reported on the body composition and bone status of male and female professional and retired jockeys, yet the variety of assessment techniques, lack of standardised testing protocols and classification inconsistency make interpretation and comparison between studies problematic. This review aimed to appraise the existing body composition and bone health evidence in jockeys and evaluate the assessment methods and classification criteria used. Dual-energy X-ray absorptiometry (DXA) has been used most frequently in jockey research to assess body composition and bone status, while various generic skinfold equations have been used to predict body fat percentage. Evidence indicates flat jockeys are now taller and heavier than the data reported in earlier studies. Absolute fat mass has steadily increased in male jockeys in the last decade. The bone status of male jockeys remains a concern as constant low bone density (BMD) is evident in a large percentage of young and experienced professional jockeys. Due to limited studies and variations in assessment methods, further research is required to investigate bone turnover markers in male and female jockeys. A standardised testing protocol using internationally recognised assessment guidelines is critical for the accurate interpretation and evaluation of body composition and bone health measurements. Furthermore, establishing jockey-specific BMD and bone turnover reference ranges should be considered using existing and future data.

Nutritional Considerations for Injury Prevention and Recovery in Combat Sports

Sports participation is not without risk, and most athletes incur at least one injury throughout their careers. Combat sports are popular all around the world, and about one-third of their injuries result in more than 7 days of absence from competition or training. The most frequently injured body regions are the head and neck, followed by the upper and lower limbs, while the most common tissue types injured are superficial tissues and skin, followed by ligaments and joint capsules. Nutrition has significant implications for injury prevention and enhancement of the recovery process due to its effect on the overall physical and psychological well-being of the athlete and improving tissue healing. In particular, amino acid and protein intake, antioxidants, creatine, and omega-3 are given special attention due to their therapeutic roles in preventing muscle loss and anabolic resistance as well as promoting injury healing. The purpose of this review is to present the roles of various nutritional strategies in reducing the risk of injury and improving the treatment and rehabilitation process in combat sports. In this respect, nutritional considerations for muscle, joint, and bone injuries as well as sports-related concussions are presented. The injury risk associated with rapid weight loss is also discussed. Finally, preoperative nutrition and nutritional considerations for returning to a sport after rehabilitation are addressed.

Nutritional optimization for female elite football players-topical review

Women's football is an intermittent sport characterized by frequent intense actions throughout the match. The high number of matches with limited recovery time played across a long competitive season underlines the importance of nutritional strategies to meet these large physical demands. In order to maximize sport performance and maintain good health, energy intake must be optimal. However, a considerable proportion of female elite football players does not have sufficient energy intake to match the energy expenditure, resulting in low energy availability that might have detrimental physiologic consequences and impair performance. Carbohydrates appear to be the primary fuel covering the total energy supply during match-play, and female elite football players should aim to consume sufficient carbohydrates to meet the requirements of their training program and to optimize the replenishment of muscle glycogen stores between training bouts and matches. However, several macro- and micronutrients are important for ensuring sufficient energy and nutrients for performance optimization and for overall health status in female elite football players. The inadequacy of macro-and micronutrients in the diet of these athletes may impair performance and training adaptations, and increase the risk of health disorders, compromising the player's professional career. In this topical review, we present knowledge and relevant nutritional recommendations for elite female football players for the benefit of sports nutritionists, dietitians, sports scientists, healthcare specialists, and applied researchers. We focus on dietary intake and cover the most pertinent topics in sports nutrition for the relevant physical demands in female elite football players as follows: energy intake, macronutrient and micronutrient requirements and optimal composition of the everyday diet, nutritional and hydration strategies to optimize performance and recovery, potential ergogenic effects of authorized relevant supplements, and future research considerations.

Associations between Dietary Inflammatory Index (DII) and bone health among postmenopausal women in the United States

OBJECTIVE

The purpose of this study was to determine the relationship between the Dietary Inflammatory Index (DII^® ) score and the bone health of menopausal women.

METHODS

A total of 2461 participants were included in the analysis from the NHANES database 2009-2018 and 2005-2006. The association between the DII and Bone mineral density (BMD) and bone mineral content (BMC) was evaluated through a multiple linear regression model.

RESULTS

The mean DII in this study was +0.89 (SD 0.18) and the scores ranged from -5.46 (most anti-inflammatory) to +4.58 (most pro-inflammatory). After adjusting for confounding factors, higher DII is associated with an increased risk of decreased total bone density (Model III, β -0.012; 95% CI -0.023, -0.001). There is a similar correlation found in bone density content and other indicators of bone mineral density. At the same time, we used BMI as a stratified variable for subgroup analysis, we found that higher DII (continuous) was associated with a significantly higher risk of decreased total bone density in overweight/obese postmenopausal women (β -0.018; 95% CI -0.025, -0.006).

CONCLUSION

A higher DII score is significantly associated with lower bone density and bone density in postmenopausal women, especially women who are overweight/obese.

Protein Requirements for Master Athletes: Just Older Versions of Their Younger Selves

It is established that protein requirements are elevated in athletes to support their training and post-exercise recovery and adaptation, especially within skeletal muscle. However, research on the requirements for this macronutrient has been performed almost exclusively in younger athletes, which may complicate their translation to the growing population of Master athletes (i.e. > 35 years old). In contrast to older (> 65 years) untrained adults who typically demonstrate anabolic resistance to dietary protein as a primary mediator of the ‘normal’ age-related loss of muscle mass and strength, Master athletes are generally considered successful models of aging as evidenced by possessing similar body composition, muscle mass, and aerobic fitness as untrained adults more than half their age. The primary physiology changes considered to underpin the anabolic resistance of aging are precipitated or exacerbated by physical inactivity, which has led to higher protein recommendations to stimulate muscle protein synthesis in older untrained compared to younger untrained adults. This review puts forth the argument that Master athletes have similar muscle characteristics, physiological responses to exercise, and protein metabolism as young athletes and, therefore, are unlikely to have protein requirements that are different from their young contemporaries. Recommendations for protein amount, type, and pattern will be discussed for Master athletes to enhance their recovery from and adaptation to resistance and endurance training.

Bioaccessibility and Bioavailability of Minerals in Relation to a Healthy Gut Microbiome

Adequate amounts of a wide range of micronutrients are needed by body tissues to maintain health. Dietary intake must be sufficient to meet these micronutrient requirements. Mineral deficiency does not seem to be the result of a physically active life or of athletic training but is more likely to arise from disturbances in the quality and quantity of ingested food. The lack of some minerals in the body appears to be symbolic of the modern era reflecting either the excessive intake of empty calories or a negative energy balance from drastic weight-loss diets. Several animal studies provide convincing evidence for an association between dietary micronutrient availability and microbial composition in the gut. However, the influence of human gut microbiota on the bioaccessibility and bioavailability of trace elements in human food has rarely been studied. Bacteria play a role by effecting mineral bioavailability and bioaccessibility, which are further increased through the fermentation of cereals and the soaking and germination of crops. Moreover, probiotics have a positive effect on iron, calcium, selenium, and zinc in relation to gut microbiome composition and metabolism. The current literature reveals the beneficial effects of bacteria on mineral bioaccessibility and bioavailability in supporting both the human gut microbiome and overall health. This review focuses on interactions between the gut microbiota and several minerals in sport nutrition, as related to a physically active lifestyle.

Habitual Dietary Status and Stress Fracture Risk Among Japanese Female Collegiate Athletes

OBJECTIVES

The aim of the present study was to identify the habitual dietary intake and stress fractures history among sport types and to determine the factors related to the risk of stress fractures among Japanese female collegiate athletes.

METHODS

This study involved 589 Japanese female collegiate athletes. We investigated habitual dietary intake (food frequency questionnaire), eating attitude (EAT-26), demographics, training status, participation in sports events, history of injury in their career, and menstrual status using a self-reported questionnaire. A multivariate logistic regression analysis was conducted to determine the risk factors associated with stress fractures.

RESULTS

Thirty percent of the total participants had a history of stress fractures, although most participants had no risk of eating disorders. Most Japanese female collegiate athletes consumed less than the dietary reference intake levels for the general Japanese female population aged 18-29 years and the athletes' dietary guideline for key bone-health nutrients such as calcium and vitamin D. The multivariate logistic regression analysis revealed body mass index (BMI; OR, 0.91; 95% CI, 0.82-0.99) and energy intake (EI; OR, 0.99; 95% CI, 0.99-0.99) as significant and independent factors in the history of stress fractures among Japanese female collegiate athletes (p = 0.047 and p = 0.039, respectively).

CONCLUSIONS

Japanese female collegiate athletes failed to meet energy and nutrient recommendations; BMI and EI were significantly associated with stress fractures, a diet that includes an appropriate amount of energy is essential.

Prebiotic Food Intake May Improve Bone Resorption in Japanese Female Athletes: A Pilot Study

The aim of the present study was to clarify the influence of inulin and lactulose-fortified prebiotic food intakes on bone metabolism turnover among Japanese female athletes. The participants included 29 female athletes aged 18–25 years. They were requested to consume their habitual foods or drinks with one pack of prebiotic food every day for 12 weeks. Dietary intake, training time, body composition, blood sample, and fecal microbiota were assessed during this intervention period. Body composition, total energy intake, and training time of the participants revealed no significant changes during the intervention period. The occupation ratio of Bifidobacterium spp. was significantly increased at 3 and 4 weeks (18.0 ± 8.3% and 17.6 ± 8.5%, respectively) compared to that of pre-intervention (11.7 ± 7.3%) (p = 0.019 and p = 0.035, respectively). The serum TRACP-5b level was significantly decreased at 12 weeks (363 ± 112 mU/dL) compared to that at baseline (430 ± 154 mU/dL) (p = 0.018). These results suggest that the prebiotic food used in this study might have beneficial effects on bone health and gut microbial environment among female athletes. Further studies are warranted to identify the mechanism of the prebiotics–gut–bone axis.

Bone mineral density in elite masters athletes: the effect of body composition and long-term exercise

BACKGROUND

The purpose of the study was to examine how bone mineral density (BMD) is related to body composition depending on the practiced sport (endurance, speed-power, throwing sports) in participants of the World Masters Athletics Championship.

METHODS

Dual-energy X-ray absorptiometry (DXA) was used to determine BMD and bone mass (BMC). Body composition was analyzed by means of the JAWON Medical X-scan analyzer using bioelectrical impedance methods. Percentage body fat (%BF), body fat mass (BFM), lean body mass (LBM), total body water (TBW), soft lean mass (SLM), intracellular water (ICW), and extracellular water (ECW) were evaluated.

RESULTS

Among men, the most important variables affecting the BMD norm were LBM (OR = 32.578; p = 0.023), ECW (OR = 0.003; p = 0.016) and ICW (OR = 0.011; p = 0.031), in the distal part and SLM (OR = 5.008; p = 0.020) and ICW (0.354, p = 0.008) in the proximal part. In women, the most important predictors of normal BMD were ICW (OR = 10.174; p = 0.003) and LBM (OR = 0.470; p = 0.020) in the distal part and ICW (OR = 5.254; p = 0.038) in the proximal part.

CONCLUSION

The representatives of strength based events had the most advantageous BMD levels. The condition of bone tissue evaluated by BMC and BMD of the forearm in masters athletes was strongly determined by the level of lean body components and the type of sports training associated with the track and field event. In the most important predictors of the BMD norm were also hydration components ECW and ICW. However, this relationship requires more research on the nature and mechanisms of these interactions.

Training Load Capacity, Cumulative Risk, and Bone Stress Injuries: A Narrative Review of a Holistic Approach

Bone stress injuries (BSIs) are a common orthopedic injury with short-term, and potentially long-term, effects. Training load capacity, influenced by risk factors, plays a critical role in the occurrence of BSIs. Many factors determine how one's body responds to repetitive loads that have the potential to increase the risk of a BSI. As a scientific community, we have identified numerous isolated BSI risk factors. However, we have not adequately analyzed the integrative, holistic, and cumulative nature of the risk factors, which is essential to determine an individual's specific capacity. In this narrative review, we advocate for a personalized approach to monitor training load so that individuals can optimize their health and performance. We define “cumulative risk profile” as a subjective clinical determination of the number of risk factors with thoughtful consideration of their interaction and propose that athletes have their own cumulative risk profile that influences their capacity to withstand specific training loads. In our narrative review, we outline BSI risk factors, discuss the relationship between BSIs and training load, highlight the importance of individualizing training load, and emphasize the use of a holistic assessment as a training load guide.

Effects of Low Energy Availability on Bone Health in Endurance Athletes and High-Impact Exercise as A Potential Countermeasure: A Narrative Review

Endurance athletes expend large amounts of energy in prolonged high-intensity exercise and, due to the weight-sensitive nature of most endurance sports, often practice periods of dietary restriction. The Female Athlete Triad and Relative Energy Deficiency in Sport models consider endurance athletes at high-risk for suffering from low energy availability and associated health complications, including an increased chance of bone stress injury. Several studies have examined the effects of low energy availability on various parameters of bone structure and markers of bone (re)modelling; however, there are differences in findings and research methods and critical summaries are lacking. It is difficult for athletes to reduce energy expenditure or increase energy intake (to restore energy availability) in an environment where performance is a priority. Development of an alternative tool to help protect bone health would be beneficial. High-impact exercise can be highly osteogenic and energy efficient; however, at present, it is rarely utilized to promote bone health in endurance athletes. Therefore, with a view to reducing the prevalence of bone stress injury, the objectives of this review are to evaluate the effects of low energy availability on bone health in endurance athletes and explore whether a high-impact exercise intervention may help to prevent those effects from occurring.

Lower step rate is associated with a higher risk of bone stress injury: a prospective study of collegiate cross country runners

OBJECTIVES

To determine if running biomechanics and bone mineral density (BMD) were independently associated with bone stress injury (BSI) in a cohort of National Collegiate Athletic Association Division I cross country runners.

METHODS

This was a prospective, observational study of 54 healthy collegiate cross country runners over three consecutive seasons. Whole body kinematics, ground reaction forces (GRFs) and BMD measures were collected during the preseason over 3 years via motion capture on an instrumented treadmill and total body densitometer scans. All medically diagnosed BSIs up to 12 months following preseason data collection were recorded. Generalised estimating equations were used to identify independent risk factors of BSI.

RESULTS

Univariably, step rate, centre of mass vertical excursion, peak vertical GRF and vertical GRF impulse were associated with BSI incidence. After adjusting for history of BSI and sex in a multivariable model, a higher step rate was independently associated with a decreased risk of BSI. BSI risk decreased by 5% (relative risk (RR): 0.95; 95% CI 0.91 to 0.98) with each one step/min increase in step rate. BMD z-score was not a statistically significant risk predictor in the final multivariable model (RR: 0.93, 95% CI 0.85 to 1.03). No other biomechanical variables were found to be associated with BSI risk.

CONCLUSION

Low step rate is an important risk factor for BSI among collegiate cross country runners and should be considered when developing comprehensive programmes to mitigate BSI risk in distance runners.

Does Protein Supplementation Support Adaptations to Arduous Concurrent Exercise Training? A Systematic Review and Meta-Analysis with Military Based Applications

We evaluated the impact of protein supplementation on adaptations to arduous concurrent training in healthy adults with potential applications to individuals undergoing military training. Peer-reviewed papers published in English meeting the population, intervention, comparison and outcome criteria were included. Database searches were completed in PubMed, Web of science and SPORTDiscus. Study quality was evaluated using the COnsensus based standards for the selection of health status measurement instruments checklist. Of 11 studies included, nine focused on performance, six on body composition and four on muscle recovery. Cohen's d effect sizes showed that protein supplementation improved performance outcomes in response to concurrent training (ES = 0.89, 95% CI = 0.08-1.70). When analysed separately, improvements in muscle strength (SMD = +4.92 kg, 95% CI = -2.70-12.54 kg) were found, but not in aerobic endurance. Gains in fat-free mass (SMD = +0.75 kg, 95% CI = 0.44-1.06 kg) and reductions in fat-mass (SMD = -0.99, 95% CI = -1.43-0.23 kg) were greater with protein supplementation. Most studies did not report protein turnover, nitrogen balance and/or total daily protein intake. Therefore, further research is warranted. However, our findings infer that protein supplementation may support lean-mass accretion and strength gains during arduous concurrent training in physical active populations, including military recruits.

Nutrition for Older Athletes: Focus on Sex-Differences

Regular physical exercise and a healthy diet are major determinants of a healthy lifespan. Although aging is associated with declining endurance performance and muscle function, these components can favorably be modified by regular physical activity and especially by exercise training at all ages in both sexes. In addition, age-related changes in body composition and metabolism, which affect even highly trained masters athletes, can in part be compensated for by higher exercise metabolic efficiency in active individuals. Accordingly, masters athletes are often considered as a role model for healthy aging and their physical capacities are an impressive example of what is possible in aging individuals. In the present review, we first discuss physiological changes, performance and trainability of older athletes with a focus on sex differences. Second, we describe the most important hormonal alterations occurring during aging pertaining regulation of appetite, glucose homeostasis and energy expenditure and the modulatory role of exercise training. The third part highlights nutritional aspects that may support health and physical performance for older athletes. Key nutrition-related concerns include the need for adequate energy and protein intake for preventing low bone and muscle mass and a higher demand for specific nutrients (e.g., vitamin D and probiotics) that may reduce the infection burden in masters athletes. Fourth, we present important research findings on the association between exercise, nutrition and the microbiota, which represents a rapidly developing field in sports nutrition.

Physical and Lifestyle Factors Influencing Bone Density in Jockeys: A Comprehensive Update of the Bone Density Status of Irish Jockeys

Compromised bone density in jockeys has previously been identified as an important health and safety concern in horseracing. Despite this, no update on the bone density status in Irish jockeys has been provided in the past decade. The study aimed to conduct a comprehensive update of the current bone density status in professional Irish jockeys and identify possible contributory physical and lifestyle factors. Eighty-five professional male jockeys (flat n = 39; national hunt (NH) n = 46) completed a dual-energy X-ray absorptiometry (DXA) scan for the assessment of body composition and bone mineral density (BMD) at the lumbar spine (LS), femoral neck (FN) and hip, 24-hour food recall, bone-specific physical activity questionnaire (BPAQ) and lifestyle questionnaire on weight making practices and injury history. Z-scores were interpreted to assess current bone density status. Correlation analysis was used to identify physical and lifestyle factors associated with bone mineral apparent density (BMAD). Results revealed a high prevalence of low BMD (Z-score < - 1.0) at the LS (44%), FN (15%) and hip (29%) in Irish jockeys. Analysis of jockeys physical characteristics found a positive relationship with the LS but not FN BMAD. Riding experience and timing of weight cut in NH and the practice of cutting weight in flat jockeys negatively influenced BMAD sites, while supplement use in flat jockeys displayed a positive effect on LS BMAD. Findings indicate the need for targeted individualised support strategies. Further investigation is required into jockey-specific intervention strategies that promote the development of optimal bone health in professional jockeys.

Relationship between muscular fitness and bone health in young baseball players

The physical actions developed by baseball players can increase muscular fitness, and consequently improve bone health. The objective was to relate some indicators of muscular fitness to bone health in young baseball players. A descriptive cross-sectional study was carried out in 102 children and adolescent baseball players of the Brazilian National Team. The age range ranged from 9.0 to 15.0 years, the average chronological age was 12.2±2.2 years and the maturity status was 14.8±0.5 APHV (age at peak height velocity). Anthropometry, body composition [% fat, fat mass (FM) and fat-free mass (FFM)], physical tests [horizontal jump (HJ) and medicine ball throw (MBT)] bone health was estimated by anthropometry [bone mineral density (BMD) and bone mineral content (BMC)]. There was positive and significant correlation between bone health with FFM (r2= 89%) and with muscle strength tests (HJ and MBT) (R2= 55 to 75%). Young baseball players classified with low bone health level, reflected decreased values of FFM, HJ and MBT, in relation to young players classified with moderate and high bone health level (p<0.05). It was shown that good bone health is a consequence of a greater presence of muscular fitness, as a result of increased physical activity. These results suggest that emphasis should be placed on those young people who present a greater risk of having low BMD and BMC.

Come Back Skinfolds, All Is Forgiven: A Narrative Review of the Efficacy of Common Body Composition Methods in Applied Sports Practice

Whilst the assessment of body composition is routine practice in sport, there remains considerable debate on the best tools available, with the chosen technique often based upon convenience rather than understanding the method and its limitations. The aim of this manuscript was threefold: (1) provide an overview of the common methodologies used within sport to measure body composition, specifically hydro-densitometry, air displacement plethysmography, bioelectrical impedance analysis and spectroscopy, ultra-sound, three-dimensional scanning, dual-energy X-ray absorptiometry (DXA) and skinfold thickness; (2) compare the efficacy of what are widely believed to be the most accurate (DXA) and practical (skinfold thickness) assessment tools and (3) provide a framework to help select the most appropriate assessment in applied sports practice including insights from the authors' experiences working in elite sport. Traditionally, skinfold thickness has been the most popular method of body composition but the use of DXA has increased in recent years, with a wide held belief that it is the criterion standard. When bone mineral content needs to be assessed, and/or when it is necessary to take limb-specific estimations of fat and fat-free mass, then DXA appears to be the preferred method, although it is crucial to be aware of the logistical constraints required to produce reliable data, including controlling food intake, prior exercise and hydration status. However, given the need for simplicity and after considering the evidence across all assessment methods, skinfolds appear to be the least affected by day-to-day variability, leading to the conclusion 'come back skinfolds, all is forgiven'.

High animal protein diet and gut microbiota in human health

The role of the intestinal flora in health and disease has become a research hotspot. Compared with carbohydrates and fats, proteins are metabolized primarily by microbial fermentation in the intestine. The production of protein fermentation products and metabolites depends on the composition, diversity, and metabolism of the gut microbiota. Several protein fermentation products, including indoles, phenols, polyamines, hydrogen sulfide (H₂S), amines, and carnitine, are toxic. This study analyzes the relationship between high-protein diets (HPDs), the intestinal microbiota, and human health and disease. Long-term HPDs increase the risk of intestinal diseases, type 2 diabetes (T2DM), obesity, central nervous system (CNS) diseases, and cardiovascular diseases (CVD) by producing toxic metabolites in the colon, including amines, H₂S, and ammonia. Short-term HPDs have little effect on the metabolism of healthy individuals under 65 years old. However, meeting the protein requirements of individuals over 65 years old using HPDs is more challenging. The adverse effects of HPDs on athletes are minimal. Natural compounds (plant extracts, whose main constituents are polysaccharides and polyphenols), prebiotics, probiotics, and regular physical exercise improve gut dysbiosis and reduce disease risk.