Hydration on Shift

Hydrating on shift is no easy feat, especially with training, workouts, and a lack of bathroom access. Staying well hydrated is not only important for general health but also essential to prevent headaches and fatigue later in the shift. Here’s how to troubleshoot your hydration goals when on shift. 

General Goals

For active firefighters, the Institute of Medicine recommendations are a good starting point:

• 92 oz (2.7 L) for women
• 125 oz (3.7 L) for men

Before you think you will drown in all that water, know that ALL fluids count. Yes, even coffee! Of course, this means a reasonable dose of coffee. One study of habitual drinkers of 25 oz coffee daily found that it was equally hydrating to water. Caffeine is a mild diuretic, meaning you will urinate more, particularly in the first hour after drinking. However, you just replaced that loss with the fluid from coffee. Therefore, research suggests that total body hydration stays the same over the day with coffee. So go ahead and tally that cup of joe towards your hydration goals!

Other liquids like juice, tea, and flavored/sparkling waters also count towards hydration goals. Even fruits and veggies have a high water content. Cucumbers, watermelon, canteloupe, strawberries, and celery are particularly high in water, plus they make a great snack. 

Fireground Hydration

The general guidelines above work for a “normal” shift, but what about fireground training and drills? Showing up to planned drills and being well hydrated ensures optimal performance and protects your heart. Dehydration can significantly impact the workload on the heart, which is concerning considering that 45% of line-of-duty deaths are related to a cardiac event.

The problem? 9/10 firefighters show up to a scheduled drill mild or moderately dehydrated. Research shows that firefighters who show up dehydrated lose 3 lbs of body weight per bottle, meaning they get dehydrated faster than the firefighters showing up well-hydrated. Stay well-hydrated to prevent that “hangover” feeling after a long day of drills!

Fluid losses on the fireground are significant – with firefighters losing up to 40 oz in 30 minutes! Water alone will not replenish these losses quickly. Electrolytes and a little sugar can help speed rehydration and prevent hyponatremia. 

Electrolytes like sodium, potassium, chloride, and magnesium are lost in sweat. Replacing electrolytes, particularly sodium, can prevent a dangerous condition called hyponatremia. Hyponatremia means blood sodium is too diluted from excessive sweat losses and excessive water ONLY replacement. Symptoms include clear urine with vomiting, headache, confusion, and muscle cramps. This is why water challenges are so dangerous!

To prevent hyponatremia and optimize rehydration, opt for an Oral Rehydration Solution like DripDrop, Liquid I.V., or Pedialyte Sport. These products have half the sugar and double the sodium of sports drinks and are 20% more effective than sports drinks for rapid rehydration. Note that sports drinks are still great for rehydration if that is all that is available.

Opt for the original products WITH sugar (not sugar-free). A little bit of glucose (10-15 g) can speed up rehydration by providing access to the sodium-glucose cotransporter on the cell. Glucose is co-transported with sodium in the intestinal tract, and water is absorbed through the osmotic gradient created by sodium and glucose. Note that you can absorb sodium and water without glucose; it will just take more time. For a dehydrated firefighter with more work to do, speed is essential. 

Tune in next month for more information on choosing an electrolyte product!

References

1. IOM Hydration Guidelines key findings link – https://www.cdc.gov/nchs/products/databriefs/db242.htm
2. Killer SC, Blannin AK, Jeukendrup AE. No evidence of dehydration with moderate daily coffee intake: a counterbalanced cross-over study in a free-living population. PLoS One. 2014 Jan 9;9(1):e84154. doi: 10.1371/journal.pone.0084154. PMID: 24416202; PMCID: PMC3886980.
3. Smith, Denise L.1,2; DeBlois, Jacob P.1; Kales, Stefanos N.3,4; Horn, Gavin P.2. Cardiovascular Strain of Firefighting and the Risk of Sudden Cardiac Events. Exercise and Sport Sciences Reviews 44(3):p 90-97, July 2016. | DOI: 10.1249/JES.0000000000000081
4. Espinosa, N. & Contreras, M. (2007). Orange County Fire Authority Hydration Study. Retrieved from https://www.iaff.org/wp-content/uploads/EIRP/Files/Rehab_SOP_Examples/Orange_County_CA/Orange-County-Hydration-Study.pdf
5. Walker A, Pope R, Schram B, Gorey R, Orr R. The Impact of Occupational Tasks on Firefighter Hydration During a Live Structural Fire. Safety. 2019; 5(2):36. https://doi.org/10.3390/safety5020036
6. Carlton, A.; Richard, G.; Orr, R. The impact of suppressing a structural fire on firefighter hydration. Aust. Strength Cond. J. 2016, 24, 27–33.
7. Sherman, T., Siekaniec, C. & Johnson, S. What’s in your sweat? CSPDA. Retrieved from https://www.sportsrd.org/wp-content/uploads/2018/11/Whats-In-Your-Sweat.pdf 
8. Efficient rehydration. Otsuka Pharmaceutical Co. Retrieved from https://www.otsuka.co.jp/en/health-and-illness/heat-disorders/replenish/ 
9. Fan PW, Burns SF, Lee JKW. Efficacy of Ingesting an Oral Rehydration Solution after Exercise on Fluid Balance and Endurance Performance. Nutrients. 2020 Dec 15;12(12):3826. doi: 10.3390/nu12123826. Erratum in: Nutrients. 2021 Oct 28;13(11): PMID: 33333771; PMCID: PMC7765193.
10. te Loo, D. Maroeska*; van der Graaf, Fedde†; Ten, Walther Tjon A.*. The Effect of Flavoring Oral Rehydration Solution on its Composition and Palatability. Journal of Pediatric Gastroenterology and Nutrition 39(5):p 545-548, November 2004. 

Megan Lautz, MS, RD, CSCS, TSAC-F 

Megan is a Registered Dietitian and coach who specializes in firefighter nutrition. Megan’s mission is to help firefighters perform better, recover faster, and enjoy long healthy retirements. Megan is the owner of RescueRD LLC, which provides nutrition seminars and coaching for tactical athletes across the country. Check out @Rescue.RD on Facebook and Instagram.