Ready for the heat before it arrives.
Heat is a condition you train and race in, not a limit you hit. One sachet a day: eight days before a hot race, or every day through a hot training block.
Informed Sport certified
Selected for the Australian Open StartUps 2026 cohort
What's in it
- 4,000mg L-taurine and four electrolytes in every sachet
- Two ways to use it: eight days before a hot race, or daily through a hot training block
- Informed Sport certified, caffeine free
Developed with Olympians. Trusted daily by athletes worldwide.
The 60-day guarantee covers opened products. If it isn’t right, email support@truefuels.com within 60 days of purchase for a full refund. See Delivery and returns
Made in the UK
Batch tested
Our philosophy
Own your physiology. We develop what it takes for you to do just that.
Same philosophy, every product: based on the latest science, test it in the real world, stripped of anything that isn’t needed to perform again tomorrow.
Used by elite athletes around the world.
How to use
One sachet a day for eight days, ending on race morning.
| Race | Seven days before, the eighth sachet on race morning |
|---|---|
| Training block | One a day through the block, a week off after 24 days |
| Daily | One sachet in 500ml of water, at the same time each day |
| Pair it | Electrolytes during the session itself |
For a plan built on your race, your sweat and the weather, build your plan on this page. For a personal recommendation, email support@truefuels.com.
What it is
An eight-day protocol of 4,000mg L-Taurine and four electrolytes per sachet, taken before the heat arrives.
Eight sachets, one a day. Use Electrolytes during the session itself.
- 4,000mg L-Taurine
- Built for heat
- Leeds Beckett University study underway
- Eight days
Delivery and returns
Delivery to the UK: 1 to 3 working days, free over £40, otherwise the fee shows at checkout.
The 60-day guarantee covers opened products. If it isn’t right, email support@truefuels.com within 60 days of purchase for a full refund.
You can cancel an order within 14 days, then return unopened products in their original condition within a further 14 days. We refund in full within 14 days of receiving them. Return postage is yours unless the item is faulty.
Faulty or damaged? Email support@truefuels.com with your order number and a photo. Full details in our returns and refunds policy.
CoreCtrl · from £28.95
Your race is hot. Your training wasn’t.
Most of the energy you burn leaves your body as heat. In a hot, humid race, getting rid of it starts competing with your legs, and a week in a warm hotel won’t change that.
02 / Why it works
Start before the heat does.
4,000mg L-Taurine
Per serve, across the full eight days.
Built for heat
For races and training blocks in hot conditions.
Study underway
Leeds Beckett University study underway.
Eight days
A simple daily routine, race morning included.
Why taurine
Taurine is an amino acid your body already makes and uses. Heat research has studied it at doses around 4g a day, taken for days before exposure, not on the day. CoreCtrl gives you 4,000mg a day for eight days, caffeine free. It doesn’t cool you down; it’s preparation, like heat training in a sachet.
Informed by Peel et al. (2024)
03 / Reviews
4.8
16 reviews
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“… Battle tested at 36 deg in the European Aquabike Championships …”
Gareth S. -
“I used the CoreCtrl-cooling system the week leading up to Swansea 70.3 Ironman race, which had temperatures in the late 20’s early 30’s on the day …”
Lester B. · Verified · after Swansea 70.3 -
“… although the run was ridiculously hot I still managed to finish, I think had I not used CoreCtrl it would have been a DNF”
Alan T. · Verified · European champs -
“… The sachets were easy to take …”
Hayley S. -
“… Using it for my heat training regime before a hot race. … Will continue to use it in training blocks and the 8-day lead up to my race.”
Dan F. · Verified · heat training
04 / The system
The truefuels cooling system
Eight days before: CoreCtrl. On the day: Electrolytes in the bottle, High Salt gels in the pocket. Three products, one job each.
-
Geles energéticos
40g Carbs per gel
From £29.95
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Electrolitos
1g Salt per stick · 390mg sodium
From £24.95
The Fourth Discipline™
The system is ours. The destination is yours.
Alistair’s Perspective
“I wanted the system to be simple. If you need fuel, use gels. If sweat losses are high, add Electrolytes. If heat is a major factor, prepare properly. The point is not to keep adding products. The point is to know what problem you are solving.”
“Racing Ironman Da Nang in 35-degree heat with a Kona slot on the line, nutrition couldn’t be an afterthought. …”
05 / Formula
What's inside. Nothing it doesn't need.
L-Taurine plus four electrolytes and black pepper extract. Six ingredients, one job: getting you ready for the heat.
This formula doesn’t stop evolving once it ships. We keep testing and refining it with sports scientists and our own athletes.
See our processPer sachet: 1 kcal, 0.3g carbohydrate.
06 / Tested
Batch tested. Nothing to hide.
Every batch is screened for banned substances before it ships.
- Informed Sport
- Batch tested
- Vegan
- Gluten free
- Caffeine free
- Made in the UK
07 / Two protocols
Two ways to use it.
One a day for eight days, the last on race morning.
Under 60kg: 2 days on, 1 day off, eight sachets over 11 days.
One a day through the block.
30 to 60 minutes before the session. Summer training, a warm-weather camp, sessions in a hot room. After 24 days in a row, a week off before restarting.
Both: one sachet in 500ml of cold water, same time each day; on training days, 30 to 60 minutes before.
08 / Race day
Choose your race. Get your protocol.
For your own numbers, built on your race, your sweat and the weather, build your plan below.
-
Marathon
Hot race: 1 CoreCtrl sachet a day from 7 days before, the eighth on race morning
30 min before: 1 Electrolytes in 500ml water
Pre-start: 1 Energy Gel
Energy Gels: 2 an hour = 80g carbs. Low Salt for normal sweat; salt marks or extreme heat: High Salt
Hydration: 150 to 250ml per gel. Heat or heavy sweat: 1 Electrolytes
Straight after: 1 Electrolytes in 500ml water -
Half Ironman
Hot race: 1 CoreCtrl sachet a day from 7 days before, the eighth on race morning
30 min before: 1 Electrolytes in 500ml water
Pre-start: 1 Energy Gel
Energy Gels: bike 2 to 3 an hour = 80 to 120g carbs. Run 2 an hour = 80g carbs. Low Salt for normal sweat; salt marks or extreme heat: High Salt
Hydration: 400 to 800ml an hour. Heat or heavy sweat: 1 Electrolytes
Straight after: 1 Electrolytes in 500ml water -
Ironman
Hot race: 1 CoreCtrl sachet a day from 7 days before, the eighth on race morning
30 min before: 1 Electrolytes in 500ml water
Pre-start: 1 Energy Gel
Energy Gels: bike 2 to 3 an hour = 80 to 120g carbs. Run 2 an hour = 80g carbs. Low Salt for normal sweat; salt marks or extreme heat: High Salt. Add on-course nutrition as needed
Hydration: 500 to 900ml an hour. Heavy sweaters: Electrolytes
Straight after: replace 100 to 150% of the fluid lost, 1 Electrolytes in 500ml water -
HYROX
Hot race: 1 CoreCtrl sachet a day from 7 days before, the eighth on race morning
30 min before: 1 Electrolytes in 500ml water
Pre-start: 1 Energy Gel
Energy Gels: mid-race (about 40 min), 1 gel, optional. Low Salt for normal sweat; salt marks or extreme heat: High Salt
Hydration: sip at each station
Straight after: 1 Electrolytes in 500ml water
09 / Your plan
Get your personalised fuelling plan.
If you have tested your sweat rate or sodium concentration, entering these will sharpen the fluid and electrolyte recommendations. Leave blank to use the algorithm's estimates.
Algorithm informed by published research on exercise fluid replacement, sweat rate, sweat sodium concentration and carbohydrate use during endurance exercise, including Sawka et al. (2007), Jeukendrup (2011) and Baker (2017). Constants: 40 g carbohydrate per gel, 1 g salt per high-salt gel, 0.25 g salt per low-salt gel and 1 g salt per electrolyte serving. Scientific estimate only. Individual variation exists. Validate all recommendations in training before race day.
10 / In their words
What athletes told us.
- 100%
- rated CoreCtrl 4 or 5 stars
16 of 16 reviews rate it 4 or 5 stars · Developed with Alistair Brownlee, who learned heat the hard way
11 / Athletes
Trusted from the podium to the parkrun.
Tap a face to read their story.
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Alistair Brownlee
“Simple things done consistently are usually what make the difference.”
Alistair Brownlee · Co-founder
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Ben Millar
“I fuel for the work I put in, to maximise adaptations and recover well so I’m ready to go again, day after day.”
Ben Millar · Reflex-Nopinz
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Malachi Cashmore
“Before I started fuelling my key sessions properly, I thought dead legs and collapsing on the floor after long rides was normal.”
Malachi Cashmore · Professional triathlete
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Joanna Tallmann
“My running has improved noticeably. That is due to consistent training and growing experience, but above all to slowly getting the hang of fuelling.”
Joanna Tallmann · Ultrarunner
Multipacks
Stock up for race season.
- 16 sachets, two protocols
- 32 sachets, four protocols, a full race season
- One protocol per hot race or heat block
12 / Questions
Questions? Answered.
Which protocol do I use?
Racing: eight days to race morning. Training: daily through the block, a week off after 24 days.
Is there a lighter dose?
Under 60kg: 2 days on, 1 day off, until all eight sachets are taken, the last on race morning. That is 11 days in total.
What does it taste like?
Mild peppermint. A few people find it unusual at first.
“Odd taste - good results.” Russ B., review via Judge.me
Does it cool me down?
No product cools you on its own, and we won’t pretend otherwise. CoreCtrl is preparation: the dose used in heat research, taken before the heat arrives.
Isn’t taurine in energy drinks?
Same amino acid. No caffeine, no sugar, and a dose and timing taken from research rather than a can.
£28.95 for one race?
£3.62 a day for the eight days before the hottest race of your year.
Do I still need electrolytes?
Yes. CoreCtrl doesn’t replace hydration; on the day use Electrolytes and your gels as normal.
Racing somewhere warm this winter?
Start seven days before you fly, not when you land.
Indoor race or turbo in a heatwave?
Use it the same way: one a day for the eight days before, the last on race morning.
“I used the CoreCtrl specifically to target an indoor cycling race which was taking place during a heatwave. I felt much more in control than in previous hot races. …” Hayley S., review via Judge.me
Multi-day event?
Eight days before, then one each morning during the event.
Delivery?
Delivery to the UK: 1 to 3 working days, free over £40, otherwise the fee shows at checkout.
Is it tested for banned substances?
Yes. Every batch is Informed Sport certified before it ships.
Is there scientific research behind it?
Yes. The formula is informed by research on taurine supplementation in hot conditions, including the work of Peel et al. (2024).
Who is CoreCtrl for?
Every athlete who trains or competes in hot or humid conditions, including marathon running, triathlon, HYROX and cycling.
“I will definitely be taking these to Kona with me in October.”
truefuels® · The Fourth Discipline™
“If heat is a major factor, prepare properly.”
Alistair Brownlee, two-time Olympic triathlon champion
Pick the race or the block, count back seven days, start there.
Shop CoreCtrl