Figuring out Fueling from Skratch Labs

Hey all. Newish to fueling or at least this level of fueling and trying to keep up.

I been very happy with the Scratch products (yes I know I can make my own for less money but that is a topic for another thread)

  1. Does anyone know the glucose:fructose ratio in their sport hydration (lemon lime) drink mix? I see cane sugar and dextrose which leads me to think 2:1, but I haven’t found anything concrete.

  2. The recommendations are 21 grams of carbs/16oz water. Is there a downside/upside to using more if my stomach can take it without issue? I’ve doubled and tripled that recommendation as an experiment without any obvious negative side effects. Is additional water needed to make this useful and I’ve just been increasing the value of my pee or can I use this as part of a fueling strategy?

Thanks as always

As the concentration of a carbohydrate drink increases, the time it spends in the stomach also increases, which reduces fluid delivery. Something around 6-8% is generally considered the best overall compromise, although YMMV and you may want to prioritize one over the other depending on the environmental conditions.

Thanks for the response. Skratch appears to be recommending a 4% solution with the reasoning being avoiding “gut rot”, so it looks like there is some wiggle room here based on that 6-8% number and personal variability.

Based on this, it looks like I can reasonably max out at 63 g/carbs in a 24 oz bottle, creating an 8% solution.

Does that mean that (in general) a denser mix is turned to waste or fat? If so, does this same logic apply to additional food based carbs for fueling, such as foods/gels/gummies/etc. Is additional water needed here?

Using more than the recommended amount of mix in a bottle will slow down your hydration - basically if you add a solution with more stuff dissolved in it than the tissues in your body (AKA hypertonic), that solution will absorb water from your body first, and then your body will absorb the solution over time. Some people are sensitive to this absorption of water into the gut and say that it creates a ‘sloshy’ feeling.

The potential ‘downside’ in all this is that if you’re getting dehydrated, and you drink a hypertonic drink, the water in the drink won’t be available to your body’s tissues until those tissues process some of the carbohydrates in the drink. So a hypertonic drink won’t as rapidly rehydrate you as an isotonic drink will. If you’re not flirting with dehydration, it’s probably not an issue at all.

OTOH, drink like beta fuel and others take a different approach. They are able to pack in more carbs without becoming hypertonic by using long chains of sugar (ie maltodextrin). Basically, 1 chain of sugar in a maltodextrin molecule has the same effect as 1 single glucose molecule on water absorption, but that chain can be many glucose molecules long. So more energy available without messing up the hydration game.


I am a big fan of Skratch Hydration mix. But its a hydration product, not a fueling product. IT is designed to absorb water quickly, the small amount of sugar in the mix helps you absorb the fluids more rapidly.

One downside to using more mix in a bottle is you also get more sodium. Ideally you want the same concentration of electrolytes in your bottle as you have in your sweat. My preference is to mix my skratch bottles a little weak.

Skratch recommends eating food for calories. So on the trainer I eat real food, fig bars, rice cakes, cookies, etc. For harder workouts I will eat gummys, sometimes sport specific and sometimes whatever I buy at the store.

If you want to drink your calories and stay with Skratch, look into superfuel. Its more spendy, but packs ~100g of carbs in a bottle using a long chain carbohydrate.



It’s valuable. Related threads below. I’ve bolded the most related.

Quick summary:

1:1 Glucose:Fructose Ratio Works better than 2:1.

90-150 grams of carbs per hour during exercise may be beneficial. 90 is not the limit.

Sucrose works as well as maltodextrin:fructose, and glucose:fructose 1:1 mixtures. >>90g/hr is optimal

Isotonicity is not as important as meeting carb and hydration needs. Both can be met with hypertonic solutions, greater than 90g/hr.

Detailed how-to guide for intra-workout fueling: (scroll to near bottom)

Running intra-workout fueling, sweetness discussion

Really spelling it out: HOW TO:

Even more how-to, with savings calculations:


Probably no need. In fact might be better to have the very high electrolyte content created by doing the multi-serving approach of the OP’s current product. Turns out, glucose + sucrose works virtually as well as malto+fruc or malto+sucrose.

6-8% is what position stands in leading journals say because it’s what keeps them out of liability’s way.

10-12% works in most cases in most people, for anything under 5hrs, where sweating is not profuse.

14-16% works well for many folks too, just not for more than ~4 hrs. I’d move towards 10-12% after the first 2-3hrs.

I said “… and stay with Skratch”. The Skratch labs hydration mix is designed for hydration… not fueling.

The problem with the multi-serving approach using Skratch the OP mentioned is how much sodium comes with the carbs. Tripling the concentration to get to 60g of carbs in a bottle will come with ~1200g of sodium per bottle. If you shoot for 90g of carbs an hour, that is 1800g of sodium an hour!!! Unless you have crazy salty sweat, that is likely to cause hydration problems.

I’ve gone full circle on Skratch for hydration. I had used them successfully for a while but then tried a number of new products. Maurten worked well but I didn’t like it for long events where I preferred some variety. I also tried GU Roctane, but if I used more than a bottle or two, I became very bloated with it and it wasn’t a good fit for me.

I tend to do a lot of 4+ hour rides, sometime up to 8 - 9 hours. For these. hydrating with Skratch has worked out best and then I get calories from a mix of Clif Bloks, Skratch and SIS bars, and SIS gels. This gives me plenty of palate variety and a very steady source of fuel without GI upset.

I use one scoop of Skratch for every 500 mL of fluid. On hot days, I simply drink more but don’t change the ratio. It has worked well and plan to stick with it again for this race season.

Actually, that’s not quite right. For sodium intake via fluid to cause diuresis (water loss) it requires MUCH MUCH higher sodium concentrations. The reason dehydration is reported from drinking ocean water is because it’s got ~35,000mg of sodium per liter of fluid. The kidneys attempt to flush that out by increasing urine production which causes water loss.

This is not the case when sodium concentration is held below 2000mg per liter. (less than 10% the concentration of sodium in ocean water). Folks are far more likely to get GI issues related to high osmolarity from high electrolyte content during exercise than they are to induce diuresis. Average folks lose 500-1500mg sodium per hour, very roughly, and dependant on about 1000 factors, and if you overconsume by let’s say, double what you’re losing, you’re not going to have dehydration. You’re going to have thirst, most likely, which will stimulate fluid consumption and probably better hydration practices during exercise.

Hence, I find it to be a pretty safe recommendation to recommend most folks who report notable sweating, to consume ~1000mg per hr. If targeting 90g per hour from Skratch, and actually hitting the 1800mg per hr sodium consumption, you’re right… it’s problematic, but probably via GI distress rather than dehydration. Simple fix: do 60g carbs from skratch, 1200mg sodium from Skratch and add table sugar for the rest of the 90g carbs.

1 Like

It’s easy to mix and match with Skratch. I have been using the products for a long time. I find that one scoop of drink (hydration) mix plus 5 scoops of Superfuel in a 24oz bottle gives me the right amount of sweetness, salt, and carbs. I drink a bottle (93g carbs & 666mg salt) about every 45 min (125g carbs and 888mg salt per hour) and have not had any issues. If I used all drink mix, that would be too sweet and salty. Try what works best for you.

1 Like

Thanks all. This has been very helpful. I have been running some experiments on myself to see how things go. I also ran a bit of this past my doctor and this was her take.

“You’re young (enough) and healthy so the extra sodium will really just be an annoyance as it can lead to more urination.” There are lot of reasons that the extra sodium COULD be a bad thing but, for me, (good blood pressure and no family history to be worried about) probably no big deal for now. Also suggested that I use a lower sodium option if the urination becomes a big deal, and the description was pretty much spot on the Skratch’s superfuel.

From the experiment side of things, I did find that I had to pee more often when increasing the mixture vs superfuel. I have noticed no difference from a performance perspective, and still no stomach issues as the urination happens later in the day. My next experiment will be using super fuel and the hydration mixed to various degrees as honestly, I don’t love the super fuel taste and could drink the hydration stuff all day.


Thank you for the insights all. This has been very helpful learning and even learning the right questions to ask.

Your doc is either oversimplifying to the point of being meaningfully incorrect, or is just wrong.

Increasing sodium intake during exercise decreases the need to urinate.

Full disclosure, I thought the same thing as your physician for a long time, so I don’t blame them.

My line of thinking that produced that incorrect conclusion was that I’d heard that if stranded at sea, you shouldn’t drink the water because it will just dehydrate you because of all the salt.

That is true.

But that’s because it’s got >30 grams of salt per liter. 30,000 mg. Not three thousand. THIRTY thousand. That’s an obscene amount of sodium and your body does respond to that with diuresis because it’s the only option to get THAT much sodium out of your system. It can’t just urinate ultra-concentrated sodium-laced urine.
So it sends enough water with it in the urine production that you end up with a net loss of hydration.


Consuming <2000mg per liter of fluid will reduce urination need, per liter of fluid consumed. That is, if you were to measure urine out put in the hours following consumption of 2 L of water vs. 2 L of water plus 2000-3000mg sodium, there would be less urine production in the scenario of having sodium added to the water.

The reason you’re noticing greater urine production later might be due to the slightly higher thirst (a good thing!) and/or delayed urination effects (also good) of consuming a high sodium beverage and then ceasing high rates of sodium consumption at the end of training when the need for aggressive hydration ceases.