Summer is here and many of you may be starting to get more active, experiencing warmer days, and hopefully having fun. One thing that many people often overlook during summer (and honestly throughout the year) is proper hydration. Afterall, cold weather is often dryer and can dehydrate as well.

For those of you that know me personally and have worked out with me (or maybe just see me in a really active coaching session) know that I sweat… A LOT! More than most people you will ever meet. I also happen to have coached a lot of people who have varying degrees of “sweatiness”. However, whether you sweat buckets like me, or perhaps not much at all, it can be pretty common to not be properly hydrated. Proper hydration also goes beyond just drinking water and it can have some consequences for your overall health and significantly impact performance during exercise.

Whether you are someone that simply doesn’t know if you are staying properly hydrated, have a hard time wanting or keeping hydration top of mind, or are looking for some easier ways to stay hydrated for you and your family, this was written for you. Special bonus section for some tips with kids who sometimes don’t have the easiest time either. While we mentioned cold weather can be dehydrating as well due to dryer air and more moisture lost through breath coupled with a decreased desire to drink/thirst, we are gearing this information to good ol’ hot sweaty Summer.

First off, it’s helpful to know how to determine if you are dehydrated. Becoming dehydrated (hypohydration) can lead to both health and performance issues (as can over/hyperhydration). Many of you may be familiar with more in-the-moment issues from dehydration in addition to thirst and dry mouth like dizziness, cramps, fatigue, nausea etc. Some of the most common health issues of more chronic dehydration can be kidney function and stones, frequent urinary tract infections, digestive issues and perhaps cognitive issues as well. So, the key is staying at optimal hydration levels for various processes in the body to keep humming along. The age-old recommendation of urine color assessment alone is not the answer either as you can be hydrated and still pee all sorts of yellows or also be overly hydrated and peeing too clearly but assume otherwise.

We will focus on dehydration here and with the summer here in California currently, that may be a more likely scenario with warmer weather and more moisture lost through the skin. Typically, you would want to combine something like urine color with some other measurement of hydration or at the least how thirsty you are.  There are devices you can buy for this and fancier scales that can help you track what percentage of your bodyweight is water reliably over time, but the former can be simpler. If your body weight is down (W = weight), your urine is a dark brownish yellow (U = urine), and you’re thirsty (T= thirst) then you are likely dehydrated. Even 2 of these can suggest the same though one alone may not be reliable (i.e. mouth breathing overnight can make you feel thirsty though not dehydrated).

Proper hydration can be something made out to be more complex than it is, so we will make things a bit simpler here but also go into some caveats around activity levels, diet, environment/temperature, and individual differences.

To note, dehydration primarily occurs through sweat and urine, though stool and respiration are pathways too. You will want to replace that fluid with a similar type of fluid as well. Something that has salts and sugar (sodium, chloride, potassium, and glucose) can be a perfect solution during loss through sweat because it is most similar to the ideal concentrations in the cells in your body and what tends to also be lost in sweat.. You don’t want just water with loss through sweat because it’s too diluted and has none if the above. If you drink a ton, you will drink it and then pee it out. Conversely if you have something too concentrated in the above ingredients it can make water move quickly to the intestines and lead to GI distress or diarrhea. There is also nothing wrong with adding some salt (sodium chloride) to your water occasionally since those (sodium and chloride) are the main electrolytes lost followed by potassium and magnesium. Most electrolyte tabs have these in varying concentrations (some with glucose) that mimic the proportions most people lose and need in their body.

As mentioned, proper hydration goes beyond just drinking water, but it is where we start with our regular personal training and holistic health coaching clients when talking nutrition. Afterall, most people do not get enough water. Beginning with 1/2 Oz per pound bodyweight can be a great starting point. Spread this throughout the day ideally so you don’t over-hydrate and signal to your body just to pee it all out. A helpful starting point can be the literal start of your day in the morning by having a tall glass of water. I personally start with 16oz mixed with greens powder, some lemon or by itself most days. 

Sometimes you may need more or less depending on diet, which we will get to next. 

Food and other drinks can contribute to your hydration status as well as things like salt/electrolytes. Whole food based diets tend to have less processing which can sometimes dehydrate the foods you eat (not always). Most fruits and vegetables are over 90% water! However, even foods like an egg can have over 70% and steak can have more than 60%. For this reason, if you eat a mostly whole food based diet you may be just fine with 50% of your bodyweight in water if you salt your food. You are also likely getting a lot more quality and quantity of necessary nutrients in your diet as well!

However, if you tend to eat a more highly processed diet that doesn’t have as much water in the foods you eat, then you may need to up your water intake to closer to 75% give or take. Another thing to note is that if the processed food you eat has a lot of salt then you may find that you don’t need to add additional salt to your meals.

Finally, various other fluids like juices, energy drinks, sodas and coffee all DO contribute to hydration status since they have mostly water in them. This is an important consideration if you have any of these during your day or perhaps an electrolyte drink like Gatorade or add in tabs/packets like LMNT for instance.

 Dietary preference is only one factor for hydration status. Certain parts of the population like the elderly and kids can be more likely to become dehydrated. Your kids can lose fluid more quickly and easily than you. Kids can also be tricky sometimes with regard to doing things to proactively stay hydrated. While very intuitive when it comes to food and drink much of the time, they may not get enough water just like adults based on their unique limitations in addition to diet and activity. Add in hot and sunny dry summer days like those in the weeks ahead and it can become trickier to keep them properly hydrated. 

There are many easy things you can do to help them though. Upping fruit intake is key. This may be easier during summer when things like watermelon, berries, or just the idea of some sweet cold fruit can be appealing. Popsicles made from diluted or freshly made at home fruit juice. You may even try this out and make extra for yourself! Encouraging your kids to eat as much minimally processed food as they like until they are satisfied versus the more processed options with help a lot too. Of course they will likely still, but it can help offset this a bit. This can go year-round of course. 

Of course, you can also make sure to have a water bottle with them and easily accessible at all times for them as you will for yourself.

Hotter Summer days can be a game changer but so can exercise and sport! Exercisers can lose between 1-5 lbs of their bodyweight from sweat in an hour on average. A decrease in just 1-2% bodyweight from water loss will lead to a 10% decrease in exercise capacity. This is a massive change in performance (difference between winning or losing) and not a lot to of water/sweat to lose! This decrease in performance can be due to things like reduced blood volume, increased core temp accompanied by decreased sweat production and therefore decreased ability to cool down, and an increased rate of muscle glycogen being used. Many activities and especially high intensity ones with little opportunity for breaks (like certain team sports) can make the opportunity for dehydration even worse. Being dehydrated also makes exercise feel way harder!

Therefore, athletes and avid exercisers will need to really stay ahead with hydration strategies both before, during, and after. You will want to replenish your fluid PLUS salts.

Before: Refer above and do what you can to start your day hydrated and stay that way

During: The Galpin Equation which we reference in another article about Minimal Effective Dose (MED article) can be helpful since it’s an easy one to remember. Your bodyweight divided by 30 per 15min of exercise (BW/30 = ounces per 15min exercise). Aim to also make a solution that is like sweat with 3-4:1 NaCl:K+ ratio (salt : potassium), 5-9% glucose, and make sure it is easy to get to and you like how it tastes!

After: Aim for 125-150% of fluids lost during exercise. You can do this by comparing your bodyweight before and after exercising and replenish those lbs in converted ounces (i.e. 2lbs lost would be 2 x 16 = 32 x 1.25 = 40 oz) . Weighing when naked is easiest and you can also note your clothing for “white crustiness” as that can be a great indicator as to whether you are someone that loses a lot of electrolytes/salts too

Remember that the amount of whole minimally processed food you eat will have BIG impact on how much extra water you need. Also remember that salt is a big one in actual fluid balance with proper hydration so you don’t just pee it out. If you tend to have a mixed diet, err on the side of caution and have more fluid when you start you day to make life easier by getting ahead of the game.

 Caffeine such as  that found in coffee or other drinks can still count as fluid even though many say it’s a diuretic. Yes, caffeine can increase urination but it is not the same to have caffeine capsules. I don’t know many people who take these but it may create confusion if you nullify the ounces of water you drink as part of your coffee. It can count toward overall hydration along with other caffeinated and non-caffeinated beverages since they are mostly water but it is not the same or nutritionally the same as plain water.

Many other factors matter. Temperature, whether cold winter days making people want to drink less and dry air pulling moisture, or hot summer days leading to more sweat can have a huge impact. Of course, exercise duration and intensity, how much you sweat compared to someone else, how much salt you lose in your sweat, the elevation you are at or train at, the ease of access to hydration, your age, etc all play big roles too. This is why it is always best to get with a coach or nutritionist who knows hydration well and can help determine you specific needs. There is some trial and error.

Hydration Cheat Sheet

1. Get ahead of the game and drink plenty of fluid as you wake up to start your day

2. 1/2 ounces per BW (or more on more processed food diet)  

3. For exercise BW/30 of fluid every 15min while exercising. Think about how fluids were dispelled to address rehydration i.e. lots of crusty sweat, you may need to replace salt in your body. Make the mixture closest to you needs based on Na, Cl, K, Glucose and maybe Mg

4. Make it even easier by having a hydrating whole food based diet. Make fresh fruit and treats like diluted fruit juice popsicles available for the kiddos who have a tougher time

5. Make hydration access easier by having a bottle and a favorite mix with you or in eyesight.

6. Exertion, diet, environment, individual differences and more can change the rules

7. Use WUT (weight, urine color, thirst level) to assess dehydration. If 2 or more are off you may be dehydrated

Citations :

1. Belval, L.N.; Hosokawa, Y.; Casa, D.J.; Adams, W.M.; Armstrong, L.E.; Baker, L.B.; Burke, L.; Cheuvront, S.; Chiampas, G.; González-Alonso, J.; et al. Practical Hydration Solutions for Sports. Nutrients 2019, 11, 1550. https://doi.org/10.3390/nu11071550

2. https://www.youtube.com/watch?v=aw8ZqF58chg