While I am not a nutritionist or dietician, there is some readily available nutritional information that I would like to share that you should consider implementing during your run practice.

Carbohydrates are the fastest fuel source for our muscles to utilize for energy while running, and actually require less oxygen to metabolize than fat for the same amount of energy production.

Most casual activities lasting less than 90 minutes do not require a fueling strategy.

60-90 minutes with intensity: Consume 30 grams/hour of carbohydrates (gel or drink)

90 Minutes - 2 Hours: 30 grams/hour of carbohydrates (gels or drink)

2-3 Hours: 60 grams/hour of carbohydrates (gels or drink)

>3 Hours: 90 grams/hour of carbohydrates (gels or drink)

See Image 1.

Even with a well executed training plan and perfect race prep, Exercise Associated Muscle Cramping (EAMC) is a common occurrence in the distance running game. With the prevalence of electrolyte drinks, one would think that they play a significant role in the reduction of exercise associated muscle cramps, but research is proving otherwise.

• The theory that EAMC are determined by hydration and electrolyte levels has been around for more than 100 years (1).

• There is little evidence that electrolyte depletion exists at time of cramping in endurance athletes but there is evidence of no significant differences in electrolyte levels existing between crampers and non-crampers (1, 2, 3, 4).

• When investigated, it has been found that crampers during a marathon have elevated levels of muscle damage compared to non-crampers, and also ran faster than their predicted times based on their training. (4). Essentially, people who cramp tend to try and run their marathons faster than their training would suggest.

• Heat does seem to play a role in muscles cramps, but the mechanism is not well understood and may be related to fatigue more than electrolyte imbalances. (1, 5)

• The cause of EAMC is still not completely understood but the importance of electrolytes and hydration status are likely overemphasized while the importance of fatigue resistance and resistance training are likely understated.

Although it may sound like the conclusion is that electrolytes do not do much, if anything, to cut down on EAMC, there is usually little harm in continuing to ingest electrolyte mixes while running, especially because many will also include some form of simple sugar.

The main takeaway from the research regarding cramping is that running your races faster than your training indicates OR not utilizing strength training during your training program are likely the leading causes of cramping.

References:

1. PMID: 18981039
2. PMID: 21148567
3. PMID: 32976313
4. PMID: 32796418
5. PMID: 31696455

Caffiene can improve race day performance. There are arguments as to whether you should reduce your caffeine intake prior to race day to make it more “potent” during your race, but I have not found this to be helpful, and if anything it may increase stress during your taper that can be detrimental to race day. I suggest low to moderate doses of caffeine (~3-6 mg/kg) pre-race, aiming to consume it 30-90 minutes prior to the start of your race.

Caffeinated gels - Because the absorption of caffeine takes ~30-90 minutes, timing of caffeinated gels is key. You likely do not want to be taking these gels with less than an hour left in your race. I suggest front loading them if you will be using them.

• Electrolytes have become synnonomous with hydrations, and with good reasons. Electrolytes have been shown to hydrate better than water alone [1}. When paired with the knowledge that increased dehydration will reduce running performance up to 2% over the course of a 12K race (this will cost you minutes in your half or full marathons), it is crucial that a proper hydration plan include the use of electrolytes if tolerated [2].
• Electrolytes DO NOT seem to influence cramping in runners during races of marathon distance or shorter when under typical weather conditions [3, 4, 5, 6].

References:

1. Maughan RJ, Watson P, Cordery PA, Walsh NP, Oliver SJ, Dolci A, Rodriguez-Sanchez N, Galloway SD. A randomized trial to assess the potential of different beverages to affect hydration status: development of a beverage hydration index. Am J Clin Nutr. 2016 Mar;103(3):717-23. doi: 10.3945/ajcn.115.114769. Epub 2015 Dec 23. PMID: 26702122.
2. Casa DJ, Stearns RL, Lopez RM, Ganio MS, McDermott BP, Walker Yeargin S, Yamamoto LM, Mazerolle SM, Roti MW, Armstrong LE, Maresh CM. Influence of hydration on physiological function and performance during trail running in the heat. J Athl Train. 2010 Mar-Apr;45(2):147-56. doi: 10.4085/1062-6050-45.2.147. PMID: 20210618; PMCID: PMC2838466.
3. Schwellnus MP. Cause of exercise associated muscle cramps (EAMC)--altered neuromuscular control, dehydration or electrolyte depletion? Br J Sports Med. 2009 Jun;43(6):401-8. doi: 10.1136/bjsm.2008.050401. Epub 2008 Nov 3. PMID: 18981039.
4. Schwellnus MP, Drew N, Collins M. Increased running speed and previous cramps rather than dehydration or serum sodium changes predict exercise-associated muscle cramping: a prospective cohort study in 210 Ironman triathletes. Br J Sports Med. 2011 Jun;45(8):650-6. doi: 10.1136/bjsm.2010.078535. Epub 2010 Dec 9. PMID: 21148567.
5. Fitzpatrick D, Walter E, Leckie T, Richardson A, Stacey M, Hunter A, Short S, Hill N, Woods D, Grimaldi R, Galloway R, Hodgson L. Association between collapse and serum creatinine and electrolyte concentrations in marathon runners: a 9-year retrospective study. Eur J Emerg Med. 2021 Jan 1;28(1):34-42. doi: 10.1097/MEJ.0000000000000739. PMID: 32976313.
6. Martínez-Navarro I, Montoya-Vieco A, Collado E, Hernando B, Panizo N, Hernando C. Muscle Cramping in the Marathon: Dehydration and Electrolyte Depletion vs. Muscle Damage. J Strength Cond Res. 2022 Jun 1;36(6):1629-1635. doi: 10.1519/JSC.0000000000003713. Epub 2020 Aug 12. PMID: 32796418.

Dehydration may not be playing a big part in cramping as previously discussed, but it sure is playing a role in your performance.

• As little as a 2% decrease in bodyweight due to sweating has been associated with significant decreased in performance.
• Dehydration leads to decreased blood volume which will lead to an increase in heart rate.
• As we exercise, our core temperature increases and we shunt blood to the surface of our skin to help with temperature regulation. Drawing an already decreased blood volume away from our muscles will likely mean decreased performance.
• If we have an elevated body temp because of decreased blood volume, we will also have a higher perceived exertion and a higher chance of a reduction in effort.

Because of these performance decreases, it is recommended that runners take in AT LEAST 8-16 oz of water for every hour of running.

(Casa DJ, Stearns RL, Lopez RM, Ganio MS, McDermott BP, Walker Yeargin S, Yamamoto LM, Mazerolle SM, Roti MW, Armstrong LE, Maresh CM. Influence of hydration on physiological function and performance during trail running in the heat. J Athl Train. 2010 Mar-Apr;45(2):147-56. doi: 10.4085/1062-6050-45.2.147. PMID: 20210618; PMCID: PMC2838466.)

Due to the sensitivity and importance of this subject I refer all my athletes to the following article written by the International Olympic Committee.

READ HERE