the use of technology to protect the health of athletes during sporting competitions in the heat

During the 2019 IAAF World Championships in Athletics in Doha and the 2020 Olympic Games in Tokyo, minimum daily temperatures are expected to be in excess of 30 C. Due to the metabolic demands of the sporting events and the high environmental temperatures, the risk of exertional heat illness (EHI) is significantly higher. Careful planning is needed to ensure that athletes are protected from irreversible long-term health damage, or even death. The greatest benefit to exercise performance is gained after about 2 weeks of heat acclimation. For maximal adaptations to occur, the heat acclimation regime undertaken should closely mimic the environmental and intensity characteristics of the conditions expected during competition. Other acute strategies are available to enhance performance in the heat including the ingestion of cold (~4 C) beverages and the use of iced towels and ice garments; these acute strategies do not replace the need for heat acclimation. The importance of responding quickly to a hyperthermic athlete cannot be understated, as minimizing treatment time will greatly improve the chances of a full recovery. Treatment time can be minimized by notifying medical personnel about the athlete's health status and the extent of any pre-competition heat acclimation strategy. Technology that allows the live transmission of physiological, performance, and biomechanical data to alert medical personnel of potential indicators of EHI should be considered. Prompt recognition of EHI will result in faster and more effective medical treatment which is crucial in protecting the athlete from irreversible and long-term health consequences, including death

The Impact of Sodium Alginate Hydrogel on Exogenous Glucose Oxidation Rate and Gastrointestinal Comfort in Well-Trained Runners

Purpose: The purpose of this study is to quantify the effect of adding sodium alginate and pectin to a carbohydrate (CHO) beverage on exogenous glucose (ExGluc) oxidation rate compared with an isocaloric CHO beverage. Methods: Following familiarization, eight well-trained endurance athletes performed four bouts of prolonged running (105 min; 71 ± 4% of VO2max) while ingesting 175 mL of one of the experimental beverages every 15 min. In randomized order, participants consumed either 70 g.h−1 of maltodextrin and fructose (10% CHO; NORM), 70 g.h−1 of maltodextrin, fructose, sodium alginate, and pectin (10% CHO; ENCAP), 180 g.h−1 of maltodextrin, fructose, sodium alginate, and pectin (26% CHO; HiENCAP), or water (WAT). All CHO beverages had a maltodextrin:fructose ratio of 1:0.7 and contained 1.5 g.L−1 of sodium chloride. Total substrate oxidation, ExGluc oxidation rate, blood glucose, blood lactate, serum non-esterified fatty acid (NEFA) concentration, and RPE were measured for every 15 min. Every 30 min participants provided information regarding their gastrointestinal discomfort (GID). Results: There was no significant difference in peak ExGluc oxidation between NORM and ENCAP (0.63 ± 0.07 and 0.64 ± 0.11 g.min−1, respectively; p > 0.5), both of which were significantly lower than HiENCAP (1.13 ± 0.13 g.min−1, p < 0.01). Both NORM and HiENCAP demonstrated higher total CHO oxidation than WAT from 60 and 75 min, respectively, until the end of exercise, with no differences between CHO trials. During the first 60 min, blood glucose was significantly lower in WAT compared with NORM and HiENCAP, but no differences were found between CHO beverages. Both ENCAP and HiENCAP demonstrated a higher blood glucose concentration from 60–105 min than WAT, and ENCAP was significantly higher than HiENCAP. There were no significant differences in reported GID symptoms between the trials. Conclusions: At moderate ingestion rates (i.e., 70 g.h−1), the addition of sodium alginate and pectin did not influence the ExGluc oxidation rate compared with an isocaloric CHO beverage. At very high ingestion rates (i.e., 180 g.h−1), high rates of ExGluc oxidation were achieved in line with the literature

Effects of EPO on blood parameters and running performance in Kenyan athletes

Introduction: Recombinant human erythropoietin (rHuEpo) administration enhances oxygen carrying capacity and performance at sea level. It remains unknown whether similar effects would be observed in chronic altitude-adapted endurance runners. The aim of this study was to assess the effects of rHuEpo on hematological and performance parameters in chronic altitude-adapted endurance runners as compared to sea level athletes. Methods: Twenty well-trained Kenyan endurance runners (KEN) living and training at approximately 2150 m received rHuEpo injections of 50 IU·kg−1 body mass every 2 d for 4 wk and responses compared with another cohort (SCO) that underwent an identical protocol at sea level. Blood samples were obtained at baseline, during rHuEpo administration and 4 wk after the final injection. A maximal oxygen uptake (V˙O2max) test and 3000-m time trial was performed before, immediately after and 4 wk after the final rHuEpo injection. Results: Hematocrit (HCT) and hemoglobin concentration (HGB) were higher in KEN compared to SCO before rHuEpo but similar at the end of administration. Before rHuEpo administration, KEN had higher V˙O2max and faster time trial performance compared to SCO. After rHuEpo administration, there was a similar increase in V˙O2max and time trial performance in both cohorts; most effects of rHuEpo were maintained 4 wk after the final rHuEpo injection in both cohorts. Conclusions: Four weeks of rHuEpo increased the HGB and HCT of Kenyan endurance runners to a lesser extent than in SCO (~17% vs ~10%, respectively) and these alterations were associated with similar improvements in running performance immediately after the rHuEpo administration (~5%) and 4 wk after rHuEpo (~3%)

Commentaries on viewpoint : physiology and fast marathons

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Addition of an Alginate Hydrogel to a Carbohydrate Beverage Enhances Gastric Emptying

PURPOSE: To examine the effect of altering osmolality or adding sodium alginate and pectin to a concentrated carbohydrate (CHO) beverage on gastric emptying (GE) rate. METHODS: 500 mL boluses of three drinks were instilled double-blind in eight healthy males while seated and GE measured using the double sampling method for 90 min and blood samples collected regularly. Drinks consisted of glucose and fructose (MON, 1392 mOsmol/kg), maltodextrin and fructose (POLY, 727 mOsmol/kg) and maltodextrin, fructose, sodium alginate and pectin (ENCAP, 732 mOsmol/kg) with each providing 180 g/L CHO (CHO ratio of 1:0.7 maltodextrin/glucose:fructose). RESULTS: Time to empty half of the ingested bolus was faster for ENCAP (21±9 min) than POLY (37±8 min), both were faster than MON (51±15 min). There were main effects for time and drink in addition to an interaction effect for the volume of test drink remaining in the stomach. There were no differences between MON or POLY at any timepoint. ENCAP had a smaller volume of the test drink in the stomach than MON at 30 min (193±62 vs 323±54 mL), which remained less up to 60 min (93±37 vs 210±88 mL). There was a smaller volume of the drink remaining in the stomach in ENCAP compared with POLY 20 min (242±73 vs 318±47 mL) and 30 min (193±62 vs 304±40 mL) after ingestion. Although there was a main effect of time, there was no effect of drink or an interaction effect on serum glucose, insulin or non-esterified fatty acid (NEFA) concentrations. CONCLUSION: The addition of sodium alginate and pectin to a CHO beverage enhances early GE rate but did not affect serum glucose, insulin or NEFA concentration at rest

The Effect of Sodium Alginate and Pectin Added to a Carbohydrate Beverage on Endurance Performance, Substrate Oxidation and Blood Glucose Concentration: A Systematic Review and Meta-analysis

Introduction Scientific and public interest in the potential ergogenic effects of sodium alginate added to a carbohydrate (CHO) beverage has increased in the last ~ 5 years. Despite an extensive use of this technology by elite athletes and recent research into the potential effects, there has been no meta-analysis to objectively elucidate the effects of adding sodium alginate to a CHO beverage on parameters relevant to exercise performance and to highlight gaps in the literature. Methods Three literature databases were systematically searched for studies investigating the effects of sodium alginate added to CHO beverage during prolonged, endurance exercise in healthy athletes. For the systematic review, the PROSPERO guidelines were followed, and risk assessment was made using the Cochrane collaboration’s tool for assessing the risk of bias. Additionally, a random-effects meta-analysis model was used to determine the standardised mean difference between a CHO beverage containing sodium alginate and an isocaloric control for performance, whole-body CHO oxidation and blood glucose concentration. Results Ten studies were reviewed systematically, of which seven were included within the meta-analysis. For each variable, there was homogeneity between studies for performance (n = 5 studies; I2 = 0%), CHO oxidation (n = 7 studies; I2 = 0%) and blood glucose concentration (n = 7 studies; I2 = 0%). When compared with an isocaloric control, the meta-analysis demonstrated that there is no difference in performance (Z = 0.54, p = 0.59), CHO oxidation (Z = 0.34, p = 0.71) and blood glucose concentration (Z = 0.44, p = 0.66) when ingesting a CHO beverage containing sodium alginate. The systematic review revealed that several of the included studies did not use sufficient exercise intensity to elicit significant gastrointestinal disturbances or demonstrate any ergogenic benefit of CHO ingestion. Risk of bias was generally low across the included studies. Conclusions This systematic review and meta-analysis demonstrate that the current literature indicates no benefit of adding sodium alginate to a CHO beverage during exercise. Further research is required, however, before firm conclusions are drawn considering the range of exercise intensities, feeding rates and the apparent lack of benefit of CHO reported in the current literature investigating sodium alginate

Recent Improvements in Marathon Run Times Are Likely Technological, Not Physiological

Every women’s and men’s world records from 5 km to the marathon has been broken since the introduction of carbon fibre plate (CFP) shoes in 2016. This step-wise increase in performance coincides with recent advancements in shoe technology that increase the elastic properties of the shoe thereby reducing the energy cost of running. The latest CFP shoes are acknowledged to increase running economy by more than 4%, corresponding to a greater than 2% improvement in performance/run time. The recently modified rules governing competition shoes for elite athletes, announced by World Athletics, that includes sole thickness must not exceed 40 mm and must not contain more than one rigid embedded plate, appear contrary to the true essence and credibility of sport as access to this performance-defining technology becomes the primary differentiator of sporting performance in elite athletes. This is a particular problem in sports such as athletics where the primary sponsor of the athlete is very often a footwear manufacturing company. The postponement of the 2020 Summer Olympics provides a unique opportunity for reflection by the world of sport and time to commission an independent review to evaluate the impact of technology on the integrity of sporting competition. A potential solution to solve this issue can involve the reduction of the stack height of a shoe to 20 mm. This simple and practical solution would prevent shoe technology from having too large an impact on the energy cost of running and, therefore, determining the performance outcome