low due to hem dilution (expansion of plasma volume) that accompanies training. So, total hemoglobin mass measurements are recommend, but when these are not available. Markers of RBC morphology, to identify microcytic (low volume). And/or hypo chromic (low hemoglobin) cells. Are recommend to identify a functional iron deficiency (Archer & Braganza, 2015. Burden et al., 2015). Hepcidin has recently emerged as a key marker of iron metabolism. providing an indicator of iron absorption. Iron supplementation results in an acute increase in hepcidin, orchestrating reduced iron absorption.
Iron supplementation may not be worthwhile in the presence of elevated hepcidin. As absorption will be compromise (Staffed et al., 2020). But, it is important to note that exercise also increases hepcidin, particularly. When exercise inflammation is present (Peeling et al., 2014). more work need in this area. And hepcidin measurement is not yet available in clinical laboratories.
Vitamin D has emerged as an important biomarker for athletes (Owens et al., 2018).
Low levels of vitamin D. particularly common in northern. latitudes where sun exposure is low. have been link to poor immune function, impaired bone health and muscle repair. Recent work has highlighted the limitations of the established. vitamin D (25-OHD) test in the context of bone health. As blacks have been show to have comparable concentrations of free bioavailable. Vitamin D despite lower 25-OHD levels (Allison et al., 2018). So, where testing is available. The bioavailable form of vitamin D (vitamin D carrier protein) should be measure.
Evaluation of the fatty acids docosahexaenoic acid
(DHA, C22:6) and eicosapentaenoic acid (EPA, C20:5). Which are incorporat into RBC membranes. Has become common among athletes, despite the scant evidence base. The omega-3 index (OM3I), a validated, reliable. And reproducible biomarker for the assessment of omega-3 status. Represents the percentage of the long-chain omega fatty acids EPA. And DHA as a proportion (%) of the total fatty acids fat from GR (Harris, 2010). Red blood cell fatty acids reflect dietary intake over the previous month. And as such can provide valuable information about the quality of the athlete’s diet. Early studies identified the potential for fatty acids to change inflammation (Calder, 2017). But various systems and/or functions can be influence by the level of fatty acids including mood. And cognition (Fontani et al., 2005), muscle recovery (Black et al., 2018). lung function ( Mickleborough et al., 2003), concussion (Oliver et al., 2016). And cardiovascular function (Hanley et al., 2017). The research evidence as it pertains. To athletes is summarize in a recent systematic review (Lewis et al., 2020a).
Energy availability
Maintaining energy availability is critical. To avoiding the many potential negative outcomes associated with energy deficiency. As recently propose in the context of Relative Energy Deficiency in Sport (RED-S) (Mount joy et al. et al., 2018). There are several peptide hormones and cytokines that serve. As indicators of energy availability. And have been associate with prolonged resistance training including lepton, gremlin. interleukin 6 (IL-6), and tumor necrosis factor alpha (Jerome et al., 2011). . More recently, low total triiodothyronine has been related to energy level. And training adaptations in female swimmers (Vanes et al., 2014). And in response to reduced energy intake in men (Fired et al., 2000). Testosterone also decreases with energy deficiency (Fried et al. 2000) and is restore with increased dietary carbohydrate intake (Lane et al., 2010).
Biomarker monitoring to inform training load
Knowing when to increase the training load. And when to reduce it is a permanent challenge for coaches and athletes. Using point-of-care (POC) blood tests offers an opportunity for rapid results. That can be immediately accessible to the 해외축구 중계사이트 scientist to assess recovery. if collect . Biomarkers of oxidative stress (eg, lipid and protein hydro peroxides. Isoprostanes, protein carbonyls), inflammation (eg, IL-6, C-reactive protein). Muscle damage (e.g., creative kinase), and hormonal stimulation (egg, testosterone. cortical) may inform the decision to increase or decrease training load. Unfortunately, only some of these are available as POC tests.
Holmes’s is a term use in toxicology that refers to a dose-response
curve where a low dose provides inadequate stimulation. Aa high dose has an inhibitory or toxic effect. Consider a set point for the athlete in training that is influence by the sum of all stress factors. ( increasing heresies) including metabolic, environmental, mechanical, psychological, immunological stress factors. And the sum of all practices that support recovery. ( lowering the hermetic set point) including nutrition, sleep, compression, cry therapy. If the biomarkers mention above are measure. They can provide an indicator of the hermetic set point.
this is a simplified framework and more research
is need to define the influence of each of these variables. But, hermetic models have been describe by several authors. Who have found that drifting well above. This set point increases the risk of overtraining. Injury and illness, and decreases the ability to adapt (Peak et al., 2015). ; Ping tore et al., 2015; Slattery et al., 2015). In our recent work it was show that, with evidence of increase oxidative stress. The risk of disease and injury increases (Lewis et al., 2020b). Other studies have shown an interaction between training load. And these biomarkers, including 1). Increasing training load with insufficient recovery in cyclists. Resulting in elevated oxidative stress and stagnant performance (Knew et al., 2014); 2). Increased training load in female swimmers with low energy availability. Resulting in decreased bioenergetics hormones (total triiodothyronine. insulin-like growth factor) and maladaptation (Vanheest et al., 2014); and 3). various biomarkers (oxidative stress. Immune function, and nutritional status) fluctuating over a season in professional rugby players. With large alterations observed during intensified training (Finaud et al., 2006).
Adaptation to aerobic exercise training can be score. By measuring the blood lactate response to control bouts of exercise. ie, a lower blood lactate response at a similar exercise intensity. What’s more, reactive oxygen and nitrogen species (RONS) are establishing themselves. As important signaling molecules for adaptation to training (Margaritelis et al., 2018). The measurement of biomarkers of oxidative stress in response. To exercise can offer information on the adaptive potential of the athlete. A recent study stratified a large group (n=100) into low, moderate. And high exercise-induced oxidative stress. Greater adaptations to a 6-week training program were observe in the moderate.
Injury and Illness Risk
In a study by Lewis and colleagues (2020b), injury. And illness were associate with a higher index of oxidative stress in Olympic rowers. More, the total antioxidant biomarker decreased with disease. And a hydroperoxide biomarker increased with injury. Using a Cox proportional hazards model. An increase of 0.5 mmol L -1in the total antioxidant biomarker exerted. A protective effect of ~30% on the disease (Lewis et al., 2020b). With high accuracy and POC facility (Lewis et al., 2016). There has been a warning against oversimplifying the establishment of a stress index. oxidative stress for these types of analyzes (Cobley et al., 2017). And So the data should be interpret with similar caution (Lewis et al., 2016).
In a sample of male and female distance runners, low levels of T3. . Had a 4.5-fold higher stress fracture rate (Heikura et al., 2018). These athletes were within the normal clinical range for testosterone. demonstrating the limited usefulness of population-based. cCinical reference ranges (see ANALYZING BIOMARKER DATA section below).
These biomarkers provide aim data to inform recovery strategies. And biomarkers of energy level, sex hormones, and oxidative stress are report. More work need to establish the predictive. power of the monitored biomarker to reduce training days lost. And the many confounding variables in high-performance environments.
HOW TO TAKE BLOOD SAMPLES?
Pre-analytical considerations
Drawing blood using a consistent method, adhering to pre-analytical rules. Is of crucial importance if the data is to be useful in detecting changes over time. The distribution of blood constituents is alter with exercise. If the exercise is prolong, unaccustom, or excessive. There may be evidence of this in the blood after several days (Hill et al., 2014). A summary of all analytical considerations is present in Figure 1. Along with a series of eight simple recommendations. To improve the quality of blood test data.