Presented by Siemens Healthineers
Q: The 2022 study mentioned common risk factors such as novice, small BMI, etc. Do you know how age relates as a risk factor for EAH. Many ultra marathons and ultra races have a high number of older adults competing. Are there increased risks with older age?
SB: This is a complex question. Indeed, the few studies on the topic tend to show a kind of bimodal distribution of age being a risk factor for EAH. Risk seems to be higher for age below 20 yrs (lack of experience) or above 50 yrs (reduced glomerular filtration). However, the main risk factor whatever the age is overdrinking.
Q: Estrogen hypothesis – does a women’s menstrual cycle impact risk for EAH. Many people can bloat or retain water during certain phases, does this impact EAH?
SB: yes likely, whereas dedicated research is missing. High level of progesterone and estrogen encountered in the mid-luteal phase are theoretical aggravating risk factor for EAH in females.
Q: How does altitude (sea level or high elevation) increase risk for EAH and thirst?
SB: It depends on what we mean by altitude and whether we consider acute or chronic exposure. At moderate altitude (1500-3000m asl), acute exposure tends to decrease AVP and promote diuresis limiting in theory the risk of EAH. At high altitude, acute mountain sickness may occur mimicking some of the symptoms of EAH, but the treatment is different, i.e.: oxygen and going down at lower altitude.
SB: I believe football (soccer) players at at limited risk of EAH. The drink to thirst messaging is particularly adapted for “general population” involved in endurance activity with limited experience.
Q: Noting the weight gain for women Ironman participants, has the availability of restroom facilities been accounted for? I’m thinking of the relative ease that men can at least urinate quickly and discretely during an endurance event compared to the complexities and literal exposure that sometimes prevents women from toileting during events. If women are consuming fluids and only eliminating by sweat, how different is that from men?
SB: this is a very valid methodological point. The Johnson et al. (2023) study does not mention if female triathletes were allowed to urinate before being weighted post event. The article only mention “Overall, females lost less weight (−0.8 ± 4.0%) than males during competition (−3.5 ± 3.8%), t(777) = −9.642, p = 0.000.” This is potentially a methodological bias, but it cannot explain why female triathletes consistently showed lower blood serum level than their male counterparts.
Q: In a pinch, out on a remote trail, during an endurance event, etc. – could salt pills or table salt under the tongue be helpful?
SB: only in long-lasting endurance event (>5-6h) if the weather is hot and dry favoring intense sweat losses and consequently intense Na+ losses (to be compensated)
Q: How often is EAH seen in high-risk populations such as cardiac patients in exercise rehab programs? Are the symptoms to watch out for the same?
SB: EAH is seen in endurance events (running distance above 15-20 km) athletes which I am not sure is a part of a cardiac rehab program.
Q: How about in high altitude or tropical environments with high heat with non-adapted athletes?
SB: see answer to other similar questions
Q: I always use pickle juice for my longer races like the Spartan Beast, for instance. How do you feel about the effectiveness of pickle juice before and/or during a race?
SB: there are limited well designed study on this niche topic. It is difficult to have a clear opinion. However, one should keep in mind that a large majority of EAH are caused by excessive drinking (whatever their sodium contents). Rather than bringing extra sodium as a countermeasure it is likely smarter to ask athlete not to overdrink.
Q: So drinking too much can have a reverse effect
SB: Yes, overdrinking leads to EAH
Q: Should general populations also wait until thirst to hydrate?
SB: Not sure I understand the question as it is not contextualized. Whether we consider a sedentary non-exercising or recreational athletes taking part to endurance races, “drinking to thirst” seems to be a reasonable approach. Frail elderly people during warm episode are likely exception to this rule.
Q: Can you clarify the difference between “Drinking to thirst” for performance vs for completing a race?
SB: in recreational athletes, drinking to thirst is a reasonable approach to limit occurrence of EAH. Elite endurance athletes sometimes have a different approach as they want to limit significant dehydration (higher than 2-3% body mass). Therefore, they often test and implement hydration plan where there are asked to drink custom made beverages at a predefined volume and frequency to maintain acceptable hydration level and to fuel (carbohydrates) the muscles.
Q: Beside NSAIDS, have you observed any antibiotics contributing to Sodium level decreases? My wife recently experienced this with Bactrim.
SB: it is true that Trimethoprim can induce hyponatremia especially when associated with a diuretic like Spironolactone. Although an inappropriate AVP secretion can be encountered with this antibiotic, the mechanism is different as Trimethoprim increases sodium losses in the urine. Here it will be more an hypovolemic hyponatremia or iatrogenic origin. Overdrinking is not the cause. Might be cautious with use this antibiotic in lasting (salt depleting) endurance events.
Q: Is he woman close to 70 who’s been working out for over 50 years? The water intake should not be different than some women that are younger.
SB: Sorry, I don’t understand the question
Q: I understand the concept of drink to thirst but is the recommendation mainly applicable to endurance sports, as you mentioned, or does it also apply to team sports such as football?
SB: Although the risk of overhydration and EAH is lower in team sports, these sports can be challenging as the breaks are sometimes limited and bringing water on the field of play may not be allowed or timely. In such case, at elite level, I would recommend applying an individualized drinking plna based on the strategy explained during the webinar.
Q: Are there any relations with the heat?
SB: yes, air temperature and relative humidity are important parameters to consider. High air temp with low humidity will favor sweating and water losses, somewhat protecting from EAH. However, if relative humidity is high and people are drinking too much, the water losses by sweating will be reduced and this could promote EAH. EAH can be ba aggravating circumstances for Exertional heat stroke and vice versa.
