How Much Water Should You Be Drinking? (For best cycling performance) 

Small modification on the sweat test. Weigh yourself holding full bottles before the test and then weigh again with the empty (or partly empty) bottles after the test. That way you account for the added weight of any water you drink and you don’t have to ride for an hour without hydration.

Steph Cronin's assertion that 2% dehydration can lead to "um up to 20% decrease in performance" is unsupportable scientifically (given that this article regards cycling and other endurance events). Up to 2% dehydration has negligible effect on performance according to most studies (those that aren't conducted for sports drink manufacturers), and some studies suggest that in endurance cycling and running up to 3% dehydration can lead to an improvement in performance due to reduced weight. however, endurance exercise in hot environments may lead to increase in core temperature which may negatively affect performance. Most elite marathon runners and high performance cyclists end their events at 2-3% dehydrated (Tucker and others, 2007,2013) and it's difficult to argue that Eliud Kipchoge or Tadej Pogacar finish their events with a 20% performance deficit Drinking to thirst has been shown in the majority of independent studies to be the most effective method of fluid balance. Further, Almost all relevant studies show that Sodium balance is homeostatically controlled in the vast majority of exercise and hydration ranges, only being over-ridden in the cases of hyponatraemia (too much drinking). Salt imbalance has been effectively demonstrated to be a non-contributory factor in localised cramp, as sodium buffer effects act globally in the body (while your heart is still pumping). Localised cramp has been shown to be solely neurological in origin. If you have a salt imbalance causing cramp you are about to die. Drink to thirst, consume some electrolytes to aid absorption of water. www.sciencedaily.com/releases/2015/07/150709092727.htm www.mdalert.com/article/every-year-more-athletes-are-injured-by-hyponatremia-than-dehydration sportsscientists.com/?s=dehydration&doing_wp_cron=1683100489.5012080669403076171875 This study supports the assertion that dehydration negatively affects performance, but highlights the paucity of good studies in this area, and shows significant concern regarding shortcomings in the assessment methods of those that are of good quality www.sciencedirect.com/science/article/pii/S2095254615000046

Love these videos, nice and brief but super helpful

My formula has always been small drinks approx. every 15 minutes. For longer rides (over 2 hours/40 miles or so) I bring 2 bottles one with water and one with dilute Gatorade. Works for me, never cramped or been dehydrated (based on the “urge to pee” test administered post ride).

Since I moved over from Europe to Thailand I changed a few things to stay hydrated. I start drinking water 30 minutes before a bike ride. I also changed my breathing from mouth to nose breathing. So during a ride my mouth is closed. No water loss through my mouth. I have one 700 ml bottle of water and one 700 ml bottle of sports drink on the bicycle. Cycling like this for 2 to three hours is no problem for me and I stay hydrated.

Amazing content. Explained simply and clearly, but in my humble opinion, one question remain: how reliable is the information on sweat loss produce by bike gps units/sportwatches, etc. ? i use a Garmin Edge 530, for an example. What's Dr.ª Steph's opinion on this matter ? Thanks in advance and keep up the good work.

As always these episodes make the "Nutrition" series very important to revisit every now and then. Thank you!

Thanks Steph. I have ordered some PREPD Prime to try out and I will doing that one hour sweat test this weekend.

she's so informative and well-spoken and supportive. i wish she was my older sister. is that weird?

I keep an old digital scale in the car and weigh myself with all my gear on including camelbak before and after riding. It’s mind blowing how much liquid I can sweat out in a 2 hour summer mountain bike ride. Ive lost close to 7 pounds by the end of a ride. From 175- 168.

Very informative. I always cramped on my vastus medialis or the teardrop muscle i had enough salt tablets ORS mixed in my sports drink enough gel but still cramped on that muscle right after the bike on transition 2 to the run. Maybe lack or training or i pushed too much.

Great content!! So, are you able to use sodium bicarbonate (SB) to get the required sodium if you body can handle the GI issues associated with SB? And how many gram/hr of sodium do you really need?

On my monthly "strava gran fondo" I'm doing the 100km in about 4hrs and only have one 850ml bottle with 1.5 tabs of SIS electrolyte in it....maybe not enough but don't feel dehydrated afterwards- might try the weighing before and after though, sounds an interesting experiment and maybe the fact I'm in the rarely warm Scottish Highlands helps 😂

a1 info cheers

I seldom feel thirsty while cycling but will drink a mug of tea when I get to the café. Maybe I will drink from a small bottle during the ride but I hardly ever feel the need to hydrate.

On 90+ degree Fahrenheit days I sweat buckets and cannot drink fast enough for rides four hours or more. I get sick and have to stop every time I try. I'm waiting for the middle of September for the temperatures to go down to try and finish a 100 mile ride without resorting to riding at grandma speeds.

I can appreciate the fact that I need about 750ml per hour, but how do you carry enough drink for long duration races with little to no water stations?

On the opposite end, can you drink too much? I had a long cycling event recently (17h on the saddle, temp between 20 and 44°C) and really paid attention to my hydration, so much that I had to pee almost every 2h. Good thing is that I was fine all day and fresh even at the end, but maybe I wasted time, energy and nutrients by drinking too much?

How do you not be too hydrated? When I am "too hydrated" before going on a bike ride, i need to stop every 30 minutes to urinate. Because that's so annoying, i dont drink that much water before riding, but of course when on the bike ride i am hydrating properly as suggested in this video. So whats the deal with over hydrating prior? How to avoid that?

Remember an Ironman is normally 7-8 hours. Remember also, re-hydrating also flushes out important micro-nutrients. You have to find a balance somehow. Are some people better naturally, or, better adapted to that 'balance' than others are?

Drinking when thirsty is just bad advice (atleast for me). Because its too late for hydration. I need to rest for 30-45 min if drink when thirst kick in or else i got bonked.

As always great information guys I have a question my wife no matter how hard she trains and on the hottest days does not sweat How does she work out how much fluid she needs

By "water" you mean "beer", right!?

I drink a lot of carbonated water at home but I am sure that is no where as beneficial as water. At least they don't list sodium in them.

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Everything is complicated these days, no talent. Floyd Landis never even had TV, but still became a Pro-Cyclist. The point am making, your body your mechanisms.