Long-term health consequences of high-carb sports drinks/gels/bars?

I’ve been mostly staying off carbs altogether and that seems to give me some pretty good extra long endurance (double century etc.), plus I don’t eat much meat, just some eggs and yogurt and such… Reading up on this forum it is kinda shocking to me how people gobble up simple sugars and other what looks to me pretty unnatural substances in the name of performance. So I wanna try going into more carbs direction but I question if that’s a wise move. I put overall health and long term health outcomes much, much higher than any kinda fitness numbers or race results. Are there any studies on the effect of gobbling up simple carbs or generally high carb diets in athletes for long-term health? Anecdotal evidence? I think it’s pretty well established that this is a really really bad idea for non-athletes, but maybe with enough load and the right timing it all works out Ok? Thanks!


I think most folks on this forum are fairly health conscious and eat right, off the bike.

On the bike, at sweet spot and above, it’s all about carbs, traditionally a 1:1 mix between sugars and maltodextrin in most gels and sports drinks. Some of the newer products are pushing towards 1:2.


I had a similar reaction to yours. From what I’ve read it seems you don’t have to do the simple sugars to make it through the 60-90 min workouts. But eating complex carbs with meals will still help to fuel better and improve RPE so that you make it through more workouts. If you need the simple sugars I’ve read other users saying they use bananas and dates, at least those aren’t artificial.


Think of “simple carbs” as fuel. If you aren’t going to do anything to use that fuel then don’t put them in the tank.

As has been stated, more intense efforts are better fuelled with simple carbs. These carbs will be used in those efforts, they don’t hang around in your body. Search the forum and you’ll find loads of carb info provided by experienced athletes.

Drinking a Coke on the bike is vastly different than drinking a Coke on the couch. :+1:


Well a Coke I ain’t touching even as a source of simple carbs but this is exactly what I’m curious about: if you put simple carbs in and burn them up right away, what does this do to the body long term? Say, can you still have a candida overgrowth and these guys getting first dibs on the sugars you put in? Can your insulin response get wonky when you get older if you keep doing this? Things like that.


I have very similar concerns as you. A few years ago I went very low carb for about 18months and found I could go on long rides with virtually no food, however there came a point when as soon as the pace on our group rides hotted up I was left really struggling. As a consequence I’ve lapsed back into a more or less conventional diet. Going forward I’m going to try to reduce what I call gratuitous carbs in my normal diet but then try to match my carb intake on the bike with my carb expenditure using drinks & bars.


One potential long term consequence is dental health. There’s a few studies out there that have found professional athletes have pretty bad dental health, particularly in endurance sports. Exposing your teeth to all that sugar throughout a long ride/run isn’t good for them, so that’s something to at least be aware of and mitigate. E.g. by rinsing with fresh water every time you consume something sugary. I’ve also seen suggestions of switching to a higher fluoride toothpaste. I generally avoid drink-based nutrition other than in races for this reason - if I’m eating my fuel then I’m naturally going to reach for the water bottle afterwards to wash it down, but if I’m drinking my fuel then I’m much less likely to do so, which means that sugar is just washing around in my mouth pretty much constantly.

Other than that I’m not aware of any studies showing long term health consequences. I generally figure that it’s probably better to save the processed sugar for the times I really need it though. Even if there’s no negative consequences, then taking on food that has some benefits (fibre, vitamins, etc) has to be better for me. So for me:

  • zone 1-3 rides are either done on just water, or if they’re long enough to need fuelling then I’ll typically do so with more natural foods like bananas, trail mix, dates.
  • Sweetspot and threshold are often fuelled naturally as well, particularly if they’re shorter and/or indoor workouts.
  • For hard group rides, harder/longer SS and threshold intervals, or races where there are easier sections to refuel, then I’ll go for processed sugar but will often use something like Haribo or Jelly Babies, though more tor taste and cost reasons than health ones!
  • For races where I need to maximise calorie intake and don’t have the luxury of easing off the pace while I’m refuelling, then I’ll use sports nutrition likes gels and drinks. This would include TTs and triathlons where I need to maintain high power throughout and also want to minimise time out of the aero position, so prefer the convenience of liquid calories. And also very long days like century+ races where you need a lot of easily absorbed calories.

Also depends on the time of year! If there’s a bunch of sugary crap around the house that needs eating (e.g after Christmas, birthdays, Halloween, etc) then I’d rather eat it on the bike than when sat on the couch…


The only thing I’d really say is that they may be simple sugars, but I wouldn’t really call them “unnatural” myself.

My n=1, I used to stick to whole foods, including protein early on, but in reality often under fuelled rides and workouts. Switching to carb bottle mix (I make my own) has definitely reduced RPE, and made me less liable to binge after outdoor spins and longer workouts! I was actually stuffed over the holidays with “real” food, and really couldn’t stomach any fuel on a gravel spin - kitchen carnage afterwards - far more damaging than actually consuming both 750ml bottles I carried around would’ve been, even in terms of added sugars!


I’d be interested in some science on this. Instinctively I go by the principle that if you use up the sugar straight away then there shouldn’t be a problem.

I think it’s easy to forget how much glycogen / carbs you use in a workout. At my FTP, just a 1-hr tempo workout like Mount Field (3x12min) will burn 696 calories, or 174 grams of carbohydrate. Even allowing for some fat burning which will vary depending on your adaptation, you’re still looking at burning through a lot of sugar even in a moderate 1 hour session. Go up to 90 minutes’ sweetspot and the sugar burn gets even bigger.

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drinking a coke on the bike is my weekend workout treat

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At my FTP, just a 1-hr tempo workout like Mount Field (3x12min) will burn 696 calories, or 174 grams of carbohydrate.

Ok thank you for this, I think I understand now one more aspect of this that makes me uneasy about pounding simple carbs during workouts. One adaptation is when easy carbs are not available so the body will try to burn more fat and maybe store carbs. The other is to train the body to be able to use up those simple carbs that you put in during/just before work outs. It feels unnatural to train the body to rely on simple carbs being available, although it’s pretty clear that performance would improve.

This begs the question: if you adapt to use simple carbs like that, what happens if one day you need to ride for 5 hours and they’re not available?

@cartsman thanks for your insightful response. This approach makes sense to me: on important missions use race gas, on everything else use regular unleaded. Seems like one might lose a bit in adaptation benefit but I’m definitely willing to take that hit.

That’s pretty unlikely to happen and you not know in advance to either carry food with you or to train specifically for it in advance.

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@dakh you can also use uncooked cornstarch (UCC) to fuel during rides. I tried this for quite some time and it worked ok for me in an endurance setting as far as outright fuel goes. The main problem was starch settling in the bottom of my water bottle and staying there. If I could get around that problem I’d still be using it. It gives you a much ‘smoother’ fuel supply during a long distance ride & doesn’t leave you with an overwhelming urge to brush your teeth every three or four hours.

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This is a great topic, and one about which I have also been concerned. It highlights our tendency to reduce these things to simplistic “I’m burning it up so it doesn’t matter” type of rationales. Taking in large amounts of carbohydrate could have deleterious effects independent of athletic performance, endocrinological or otherwise. Our history of understanding nutrition in all respects is littered with examples of thinking we had it figured out only to later find contradicting evidence and wondering in retrospect what the heck we were all thinking.

Michael Pollan: “Eat food. Not too much. Mostly plants.” Beyond this, you’re probably in choppy waters.


I do think it’s worth considering the origin of the carbs, since I’d imagine some are using sugars like gels when it’s probably not really necessary.

I agree with the oversimplification argument. If that simple we should apply the same to other foods. Despite that, it has been shown that the body works massively differently when you intake sugars in either fruit form, or as sweets (candy). I think it was Michael Gregor, but someone found a gem of a study which showed that people essentially trying to overeat fruit - result: they had no obvious adverse affects, the fruits and their bodies self-regulated the response in a much healthier way, despite having 20+ pieces of fruit a day in comparison to the equivalent amount in processed ways, which lowered the body’s sugar levels to alarming rates (study was related to weight gain and eating habits). In between was fruit blended, so it shows having the full wholesome variety is what the body prefers.

Yes for a hefty race, a gel works like rocket fuel. I am now scaling these back though, also Clif bars etc. I opt for more ‘natural’ alternatives where possible. I guess I’d think differently if I were a pro though.

Nice thread!

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What do you find so objectionable about coke beyond the simple carbs? It’s basically sugar, water, and caffeine. Some would call that a pretty good endurance fuel. From a health standpoint, no better or worse than a gel.

I do have concerns about the dental health side of the all the sugar. I’ve had 2 cavities in the past 5 years after being cavity free for ~30 years. I’ve definitely increased my use of gels on the bike in the last 5 years. Maybe a coincidence, but all the sugar can’t be helping the teeth.


Lets put it this way - if you saw a kid at Walmart downing a GU gel while sucking on a bottle of Gatorade, what would you think of his mother?

Gels and sports drinks are a necessary evil of long bike rides but just because you’re wearing Lycra while using them doesn’t change the fact they’re basically candy and pop.


Yeah I am similar, had great teeth health until recently where I started doing long course triathlon and have had a bunch of fillings needed. I have recently become much more careful about how I take my sugars and try to rinse my mouth with water after I drink from a sugary drink. I only use sugary drinks on longer rides and also use real food.

I also have recently started chewing sugar free xylitol gum regularly and I hope it helps. I do notice that my mouth is not dry anymore/as much while doing this, it helps me deal with the uncomfortably of some difficult workouts mid-ride and my mouth always feels clean/no feeling of wanting to brush my teeth after workouts. I am hoping this reduces the amount of sugar sticking around in my mouth and I am honestly going to use it starting race season, including my full Ironman this summer. I will even go as far as to put another pack in my special needs so I can have a fresh pack in case I drop it on the bike, and might put on for myself on the run. Love that stuff. Costco megapacks of trident spearmint; lasts 1-2 hours per stick and it gives my mind something to do. Hopefully my jaw wont be tired after 8-9 hours though…

Very interesting topic. Maybe it’s worth discussing on the podcast. If natural fuel like dried fruits, fruit purées, honey, natural syrups etc. have the same effect as all of the usual gels and sports drinks then it only seems logical to opt for the natural alternatives… I have to admit that this crosses my mind pretty regularly. There are natural gels available but they’re very very expensive (picked up this one recently and very pleased with it, thinking about making the mix myself but seems very hard to get the ratios right https://innerme.eu/en/energy-gel-performance-40g)