A Fuelling Guide Built on SiS Beta Fuel: Using "1:0.8", Lessons from Froome's 80 km Solo Attack
Introduction: why Beta Fuel?
In my previous article, "From Lactate Gels to 1x Drivetrains: The 2026 Endurance Trends",
I explained that 120 g of carbohydrate per hour has become standard for pros during races.
So what, and how, do you actually eat to reach that amount?
One answer is Beta Fuel from the British sports nutrition brand Science in Sport (SiS).
Developed with Team Sky and now used by INEOS Grenadiers, it's a high-carbohydrate fuel
that gives you 40 g of carbohydrate in one gel and 80 g in one drink.
In this article, based on SiS's official website, fuelling guides and product specification sheets, I cover Beta Fuel's history, how it works,
and how to use it in training and racing. Unless stated otherwise, the figures on its effects come from SiS.
The origin story: Froome's 80 km solo attack at the 2018 Giro
25 May 2018, stage 19 of the Giro d'Italia.
Chris Froome was 3 min 22 sec behind race leader Simon Yates, and his chances of winning looked hopeless.
He made his move on the Colle delle Finestre, an 18.5 km climb including dirt roads.
Froome attacked there and rode the remaining roughly 80 km to the finish completely alone.
He won the stage and took the maglia rosa, then went on to win the race overall.
Froome himself has called this day the greatest achievement of his career.
The "18% drink" behind the attack
Team Sky built fuelling into its plan for this solo attack.
Riding about 80 km alone takes a huge amount of carbohydrate.
The team placed staff at points all along the course to keep handing Froome food and drink.
Team principal Dave Brailsford also said that the fuelling strategy played a big part in the win.
At the centre of it was a new drink developed jointly by SiS and Team Sky.
Developed by the team's then head of nutrition James Morton and others, it had been tested at warm-up races and training camps since around February 2018.
One 500 ml bottle gives you about 80 g of carbohydrate, the equivalent of four rice cakes
A concentration of 18%, two to four times that of typical sports drinks (4–8%)
Even so, to avoid upsetting the gut, it was made close to the concentration of body fluids (isotonic) with a neutral pH
SiS says the plan for the final stages of the Giro, stages 17–20, was to cover 4,000–6,000 kcal a day, mainly from carbohydrate.
In the cold on the Finestre, the body burns even more carbohydrate.
The story goes that continually replacing it is what made the 80 km solo attack possible.
How it evolved
When | What happened |
|---|---|
June 2018 | First unveiled right after the Giro win. 81 g of carbohydrate per sachet of powder, with two sugars in a 2:1 ratio. At the time it was team-only |
2020 | INEOS Grenadiers joined the development of a new formula. That year, Tao Geoghegan Hart won the Giro overall |
July 2021 | A new range launched with the ratio changed to 1:0.8, in four forms: drink, gel, nootropic gel and chews |
A drink created to decide Grand Tours has changed shape and become available to the rest of us.
What does "1:0.8" mean?
The "1:0.8" printed large on Beta Fuel packaging
is the ratio of two sugars: maltodextrin and fructose.
Why mix two kinds of sugar?
Maltodextrin is a carbohydrate that breaks down into glucose.
Glucose and fructose are absorbed through separate "entrances" in the gut.
With glucose alone, there is a limit to how much you can absorb per hour,
and anything beyond that sits in your gut and causes discomfort.
So by adding fructose and using the other entrance as well, you increase the total amount you can absorb.
The 2:1 ratio of two parts glucose to one part fructose used to be the norm,
and the original Beta Fuel used it too. From the 2021 range, fructose was increased and the ratio changed to 1:0.8.
The benefits SiS claims
SiS describes the effects of 1:0.8 as follows:
Up to 17% better energy efficiency: the share of the carbohydrate you take in that is actually burned for energy rises from 62% to 74%
Higher peak power in all-out sprints
Less bloating and gut discomfort
The evidence it cites
is a 2013 study showing that the ratio of fructose to maltodextrin affects how carbohydrate is burned.
What later research found
In 2022, a European applied physiology journal published this study.
Eleven highly trained male cyclists rode for three hours, comparing two fuelling methods.
Fuelling method | Rate of burning ingested carbohydrate (120–180 min) |
|---|---|
1:0.8, 120 g per hour | 1.51 g per minute |
2:1, 90 g per hour (previous recommendation) | 1.29 g per minute |
With 1:0.8 at 120 g, riders burned more of the carbohydrate they took in.
This also matches the "1.5 g per minute" SiS cites in its history article.
However, the amount of stored carbohydrate (glycogen) used was about the same with both.
The authors conclude that the effect on performance needs further study.
It has been shown that you can take in more and burn more, but we can't yet say that you'll go faster as a result.
Incidentally, the specification sheet for the nootropic gel
lists 29.4% maltodextrin and 22.6% fructose. That's a ratio of about 1:0.77, matching the label.
Choosing from the range
Beta Fuel comes in four forms that you eat differently, plus a post-exercise recovery product.
They all use the same sugar blend; what differs is the amount per serving and how easy they are to take.
Product | Carbs per serving | Best for |
|---|---|---|
Energy Gel | 40 g | The basic choice while riding. Straight out of your pocket and down |
Energy Gel + Nootropics | 40 g | The decisive moments late in a race. Contains 200 mg of caffeine |
Energy Chew | 45 g per pack (about 7 g per chew) | Early in a ride or easier sections. Chewing gives it a feeling of real food |
Beta Fuel 80 (drink) | 80 g | In your bottle for fluid and carbs at once. Also good for race-day breakfast |
Beta Recovery | 60 g + 30 g whey protein | Straight after you finish. Sugar ratio 1:1 |
On SiS's official Japanese site, flavours include orange, strawberry & lime, lemon & lime, and unflavoured.
The trick to using them: "chews while you can still chew, gels when it gets hard".
SiS's fuelling guide also puts chews in the first half and gels in the second half in its 100 km race example.
Eating the same texture all the time gets tiresome, so combining them has value in itself.
Understanding the nootropic gel
The product in the range that draws the most interest is the Nootropics Plus.
Nootropics are ingredients said to support brain function such as concentration.
SiS says it "brings out both physical and mental power". Let's look at what's inside, based on the specification sheet.
What's in one gel (60 ml)
Item | Per gel |
|---|---|
Energy | 159 kcal |
Carbohydrate (of which sugars) | 40 g (19 g) |
Caffeine | 200 mg |
L-taurine | 1,000 mg |
Citicoline (Cognizin®) | 250 mg |
L-theanine | 200 mg |
Salt equivalent | 0.04 g |
The star is caffeine, an ingredient well known for reducing how hard exercise feels.
200 mg is about the same as two cups of drip coffee.
On top of that, it contains taurine, citicoline and theanine.
How well this combination of three works isn't known beyond what the manufacturer says.
The specification sheet also tells us the following:
The flavour is tart lemon with a hint of lime and a slightly bitter aftertaste. It's a thin, semi-liquid gel
Free from the 14 major allergens. Suitable for vegetarians and vegans
Tested by the third-party Informed programme to confirm it contains no banned substances
Three things to know before using it
1. No more than one a day
The specification sheet says in bold: "Do not consume more than one per day."
In fact, SiS's marathon fuelling guide includes an example using two during a race (400 mg of caffeine in total).
But here I recommend following the label: one a day.
If you combine it with coffee or other caffeinated gels, watch your total intake.
It isn't recommended for children or for women who are pregnant or breastfeeding.
2. Take it late
The manufacturer recommends taking it in the second half of long endurance efforts.
On a long ride, use it near the end when fatigue sets in, or before the final climb.
3. Almost no salt
Each gel contains only 0.04 g of salt equivalent.
On hot days or long efforts, prepare a separate electrolyte drink (from SiS, HYDRO+ for example).
Fuelling plans by session
Read SiS's Cycling Fuelling Guide and you'll notice something surprising: Beta Fuel isn't used in more than half of the sessions.
For sessions under two hours, it recommends the maltodextrin-only GO range (such as GO Isotonic Gel, 22 g per gel).
Session | Intensity / duration | Carbs while riding | Main products |
|---|---|---|---|
Recovery ride | 30–55% FTP, 1–1.5 hours | None (water and electrolytes only) | HYDRO+ |
Tempo ride (zone 2) | 75–85% FTP, 1.5–2 hours | 60 g/h | GO Isotonic Gel |
VO₂max / anaerobic intervals | 106%+ FTP, about 1 hour | 60 g/h | GO Isotonic Gel, GO Caffeine Gel |
Threshold ride | 90–105% FTP, about 2 hours | 80 g/h | Beta Fuel gels |
Endurance ride (long) | 56–75% FTP, 3–4 hours | 85 g/h | Beta Fuel gels and chews |
* From SiS's Cycling Fuelling Guide. Example for an 80 kg rider
The dividing line: use Beta Fuel if the session is over two hours, or if it involves long periods of high intensity near FTP.
Up to 60 g an hour, a single type of sugar can be absorbed fast enough.
The long ride is a race rehearsal
The guide puts particular emphasis on 3–4 hour long rides.
It treats them as days to try everything you'll do on race day: clothing, equipment, the meal the day before and fuelling on the bike.
In the guide's example, you take the following every 30 minutes:
Right after the start: chews (45 g)
30 min: gel (40 g)
60 min: chews (45 g)
90 min: nootropic gel (40 g)
120–180 min: a gel (40 g) every 30 minutes
The basic rule is to take each with 250 ml of water. Suddenly taking this much can upset your stomach, so
start at 60 g an hour and increase it a little on each long ride.
Fuelling plans by race
The thinking is the same for races. Short races need little fuel on the bike; the longer the race, the more Beta Fuel comes into play.
Race | Duration | Carbs while riding | Key points |
|---|---|---|---|
Time trial (16 km) | 20–35 min | None | Beta Fuel chews and HYDRO+ 45 minutes before the start. Take 200 mg of caffeine at this point too |
Criterium | About 60 min | 60 g/h | Mainly GO gels. Take a caffeinated one early so it kicks in for the final sprint |
50 km | About 2 hours | 85–90 g/h | Every 25 minutes: chews twice → gels twice |
100 km | 3–4 hours | 85–90 g/h | Every 30 minutes: chews four times in the first half, gels four times in the second half |
160 km | 5–6 hours | 80–90 g/h | Combine chews, gels, Beta Fuel 80 drink and solid GO Energy Bakes |
* From SiS's Cycling Fuelling Guide. Example for an 80 kg rider
Fuelling timeline for a 100 km event
This example assumes a course of around 100 km, common at long-ride events in Japan.
I've put the plan from SiS's guide into a table. Just one nootropic gel, in the second half.
Time | What to take | Carbs |
|---|---|---|
0 min | Chews + 250 ml water | 45 g |
30 min | Chews + 250 ml water | 45 g |
60 min | Chews + 250 ml water | 45 g |
90 min | Chews + 250 ml water | 45 g |
120 min | Nootropic gel + 250 ml water | 40 g |
150 min | Gel + 250 ml water | 40 g |
180 min | Gel + 250 ml water | 40 g |
210 min | Gel + 250 ml water | 40 g |
30 min after finishing | Beta Recovery | 60 g + 30 g protein |
In total that's four packs of chews and four gels. It all fits in your jersey pockets, so you can fuel at your own pace without relying on feed stations.
Aim for about 500 ml of fluid per hour. On hot days, it's reassuring to make one of your bottles an electrolyte drink.
The day before and race-day breakfast
Just as important as fuelling on the bike is filling up the tank before the start.
SiS explains that the body can store only about 500 g of carbohydrate, while a long race can use up 600–1,000 g.
Carb-loading the day before
Race | Daily carbohydrate | When |
|---|---|---|
Criterium (about 1 hour) | 6–8 g per kg of body weight | The day before |
Long events / endurance races (3–6 hours) | 10–12 g per kg of body weight | From two days before |
For a 65 kg rider aiming for 10 g/kg, that's 650 g a day. From rice alone, that would be about 1.8 kg, too much to eat in normal meals.
SiS recommends choosing low-fibre foods and taking some of it as drinks and fuel products.
In the guide's example, Beta Fuel 80 drink is added at lunch and chews as snacks.
With Japanese foods, white rice, udon, mochi, castella, bananas and 100% fruit juice are easy options.
Cut back on high-fibre foods such as brown rice, vegetables and beans for that day only.
Race-day breakfast three hours before
On race day, eat 2–3 g of carbohydrate per kg of body weight 2.5–3 hours before the start.
Overnight, the carbohydrate (glycogen) in your liver drops by about half, so the aim is to top it up.
SiS recommends including foods containing fructose, which the liver stores easily, or a Beta Fuel drink at breakfast.
Here's an example for a 65 kg rider taking 3 g/kg (about 195 g).
Food | Approx. carbs |
|---|---|
300 g white rice | about 110 g |
2 pieces of mochi | about 50 g |
1 banana | about 20 g |
200 ml orange juice | about 20 g |
Total | about 200 g |
Figures are typical values for common foods. The usual mistakes here are eating too much and eating right before the start.
Setting off with a heavy stomach leads to gut trouble.
The ideal start is "a light stomach, with muscles and liver full". Always try any new amount or food on a training day first.
Verdict for amateur riders, and summary
Beta Fuel is a fuel created to decide Grand Tours.
That means there's a clear split between where it suits and where it doesn't.
◎ A great ally for long rides and long events: if you're taking 80–90 g an hour on rides over three hours, the combination of 40 g gels and 45 g chews is practical. You don't need to carry as many in your pockets
△ Overkill for sessions under two hours: SiS itself recommends the GO range for sessions this long. On price too, other fuels are plenty for everyday training
△ Save the nootropic gel for that one key moment: no more than one a day. I recommend using it at the decisive point late in a race
Above all, the most important thing is to try it in training before the big day. Froome's 80 km solo attack, too,
depended on fuelling that had been tested at warm-up races and camps. Start with 60 g an hour on your next long ride.
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