Macroscopic hematuria caused by running-induced traumatic bladder mucosal contusions

Prevalence of anemia and iron deficiency and its association with body mass index in elite Japanese high school long-distance runners

OBJECTIVES

Anemia is a common condition in long-distance runners (LDRs). Recently, not only iron deficiency (ID) but also energy deficiency has been considered as a risk factor for anemia in athletes but no evidence has yet been established. The aim of this study was to investigate the prevalence of anemia and ID and the influence of body mass index (BMI) on anemia in high-school LDRs.

METHODS

The participants were 406 male and 235 female elite Japanese LDRs who competed in the All-Japan High-School Ekiden Championship 2019. They submitted their anthropometric data and results of a blood test within five days after the competition. The prevalence of anemia and ID and the influence of BMI on anemia were assessed retrospectively.

RESULTS

Mean hemoglobin concentrations (Hb) were 14.8 ± 0.9 g/dl in males and 13.2 ± 0.9 g/dl in females. The prevalence of anemia (Hb < 14 g/dl in males and < 12 g/dl in females) was significantly higher in males (16.3%) than females (6.4%), but males also showed higher prevalence of non-iron deficiency anemia (NIDA) than females (11.6% and 3.0%, respectively). No significant gender difference was found in the prevalence of iron deficiency anemia (IDA) (4.7% in males and 3.4% in females). ID (serum ferritin level < 25 ng/ml) was significantly more prevalent in females (37.4%) than males (18.5%). A binary logistic regression analysis revealed that low BMI was a contributor to anemia in females (odds ratios: 0.577 (95% CI: 0.369-0.901), p = 0.012).

CONCLUSION

In Japanese high-school LDRs, one in six males was anemic, but most males did not have ID. Conversely, one-third of females were diagnosed with ID. Lower BMI was identified as a risk for anemia in females, suggesting that leanness may also lead to anemia in females.

The IRONy in Athletic Performance

Iron is an essential micronutrient for athletes, intricately linked to their performance, by regulating cellular respiration and metabolism. Impaired iron levels in the body can significantly hinder athletic performance. The increased demand for iron due to exercise, coupled with potential dietary iron insufficiencies, particularly among endurance athletes, amplifies the risk of iron deficiency. Moreover, prolonged exercise can impact iron absorption, utilization, storage, and overall iron concentrations in an athlete. On the contrary, iron overload may initially lead to enhanced performance; however, chronic excess iron intake or underlying genetic conditions can lead to detrimental health consequences and may negatively impact athletic performance. Excess iron induces oxidative damage, not only compromising muscle function and recovery, but also affecting various tissues and organs in the body. This narrative review delineates the complex relationship between exercise and iron metabolism, and its profound effects on athletic performance. The article also provides guidance on managing iron intake through dietary adjustments, oral iron supplementation for performance enhancement in cases of deficiency, and strategies for addressing iron overload in athletes. Current research is focused on augmenting iron absorption by standardizing the route of administration while minimizing side effects. Additionally, there is ongoing work to identify inhibitors and activators that affect iron absorption, aiming to optimize the body's iron levels from dietary sources, supplements, and chelators. In summary, by refining the athletic diet, considering the timing and dosage of iron supplements for deficiency, and implementing chelation therapies for iron overload, we can effectively enhance athletic performance and overall well-being.

Anemia in Sports: A Narrative Review

Recent years have brought about new understandings regarding the pathogenesis of anemia in sports. From hemodilution and redistribution considered to contribute to the so-called “sports anemia” to iron deficiency caused by increased demands, dietary restrictions, decreased absorption, increased losses, hemolysis, and sequestration, to genetic determinants of different types of anemia (some related to sport), the anemia in athletes deserves a careful and multifactorial approach. Dietary factors that reduce iron absorption (e.g., phytate, polyphenols) and that augment iron’s bioavailability (e.g., ascorbic acid) should be considered. Celiac disease, more prevalent in female athletes, may underlie an unexplained iron deficiency anemia. Iron loss during exercise occurs in several ways: sweating, hematuria, gastrointestinal bleeding, inflammation, and intravascular and extravascular hemolysis. From a practical point of view, assessing iron status, especially in the athletes at risk for iron deficiency (females, adolescents, in sports with dietary restrictions, etc.), may improve the iron balance and possibly the performance. Hemoglobin and serum ferritin are measures that are easily employable for the evaluation of patients’ iron status. Cutoff values should probably be further assessed with respect to the sex, age, and type of sport. A healthy gut microbiome influences the iron status. Athletes at risk of iron deficiency should perform non-weight-bearing, low-intensity sports to avoid inducing hemolysis.

Potential Use of Wearable Sensors to Assess Cumulative Kidney Trauma in Endurance Off-Road Running

(1) Background: This study aimed to explore wearable sensors' potential use to assess cumulative mechanical kidney trauma during endurance off-road running. (2) Methods: 18 participants (38.78 ± 10.38 years, 73.24 ± 12.6 kg, 172.17 ± 9.48 cm) ran 36 k off-road race wearing a Magnetic, Angular Rate and Gravity (MARG) sensor attached to their lower back. Impacts in g forces were recorded throughout the race using the MARG sensor. Two blood samples were collected immediately pre- and post-race: serum creatinine (sCr) and albumin (sALB). (3) Results: Sixteen impact variables were grouped using principal component analysis in four different principal components (PC) that explained 90% of the total variance. The 4th PC predicted 24% of the percentage of change (∆%) of sCr and the 3rd PC predicted the ∆% of sALB by 23%. There were pre- and post-race large changes in sCr and sALB (p ≤ 0.01) and 33% of participants met acute kidney injury diagnosis criteria. (4) Conclusions: The data related to impacts could better explain the cumulative mechanical kidney trauma during mountain running, opening a new range of possibilities using technology to better understand how the number and magnitude of the g-forces involved in off-road running could potentially affect kidney function.