Running Dehydration Symptoms
Water intake is absolutely crucial in facilitating blood flow to the key parts of the body that are under stress when we run. It’s common knowledge that blood carries oxygen, nutrients, and sodium to working parts of the body, those being our heart, lungs, and muscles. When dehydration occurs, our blood thickens, reducing the rate of blood flow to these key systems and body components, reducing performance and placing undue amounts of stress on the body. Think of it like this – blood transports our fuel: food and water! Generally speaking, the harder you run, the more water your body will use.
How do you know if you’re dehydrated whilst running?
There are a number of easily identifiable symptoms which I’m sure you’ve heard of before. The first one is feeling thirsty. It is true that you’re already dehydrated, or on a path to dehydration if you feel thirsty. So drink before you feel the signals. Other symptoms include (this list is not exhausted):
Increased fatigue and feeling a lack of energy
Headaches
Dryness in mouth
Stomach upset, often runners complain of gastrointestinal (G.I) distress
Cramping of muscles – for me personally, my calves cramp at night sometimes causing a bad sleep if I haven’t had enough water in the day, stomach cramps
Seeing stars, feeling dizzy and/or lethargic
Inability to/and or difficulty concentrating
We need to remember that around 60% of our body is composed of water, so it makes up a fair amount of our total body weight. As discussed above, if the runner were to lose roughly 2% of their body mass, endurance performance will decrease. This means a slower pace, reduced recovery ability, and an all-round bad experience. Why let something you can control and plan for race day, ruin your run? If we drink fluid in the correct amounts, timed well, we can ensure better performance on your next run or race day.
Have you ever heard of the term “bonking” or “hitting the wall”, in association with running? Bonking means a sudden loss of energy and a high onset of fatigue. Dehydration can contribute to “bonking”, which essentially leads to a drastic reduction in athletic performance and a potential inability to continue the athletic activity. It is also largely a result of a lack of glycogen availability to send to the muscles and liver. I’d recommend for events longer than an hour, sipping on a carbohydrate-electrolyte solution, alongside easy to digest snacks to prevent bonking. For events less than 1 hour, staying well hydrated in the days before, the morning of and afterward is crucial.
Another thing to consider is some people sweat more than others. This can be to do with the person’s gender, size, and weight. What this means for the runner, is it is a very personalized approach. The plan must be tried and tested. Don’t try something new on race day, or too close to race day.
How do you avoid dehydration when running?
The top priority is to replace water that has been lost through sweating post-exercise for shorter running sessions and sip on water for sessions longer than 1hr. It is also important to maintain hydration throughout the day, including before exercise. No need to go overboard, however, a glass of water in the morning, first thing can really help kickstart the day and set you up for a better run. As someone who hasn’t drunk enough water in the past, I recently made it a habit to have a glass of water as my first task in the morning, and I have felt better throughout the day as a result of this.
An Oxford Academic article observed the relationship between dehydration and endurance performance in competitive athletes. The main takeaways from this article are the importance of beginning exercise well-hydrated for longer bouts of endurance exercise (which can be monitored by urine color; pale is generally better), and encouragement of mouth-rinsing with sports drinks throughout the activity.
It is possible that Mouth rinsing Carbohydrate solutions could be beneficial for endurance performance, i.e running. This process involves sipping and swishing around a “carbohydrate-electrolyte solution” in your mouth during the endurance event. Whilst there has been little study on the potential benefits of this method, the evidence suggests that endurance performance around 1 hour in length if the “subject has fasted”, can have a beneficial effect on performance. I have done this myself in races around 10km, and longer runs, however not in a fasted state. What I did find from a performance standpoint is less hunger upon finishing my run, I didn’t feel as fatigued at the end, and I felt I could’ve run further if I desired. I do believe there is something to be said for this. This particular study revealed that “studies using functional MRI and transcranial stimulation have provided evidence that carbohydrate in the mouth stimulates reward centers in the brain and increases corticomotor excitability.” Essentially, the brain is tricked into improving performance which is likely associated with corticomotor excitability.
I explore how to avoid dehydration further, race hydration strategy, over-hydration and tips and tricks in my blog post. Click if you'd like to give it a read:
https://larahamilton.com/running-dehydration-symptoms/