Precision Fuel & Hydration treats fuelling as a trainable performance lever. Here's how to coach carbs-per-hour and the gut.
Most endurance clients under-fuel, blow up, and blame their fitness. Precision Fuel & Hydration (Andy Blow) reframes fuelling as a lever you coach: match carbohydrate-per-hour to the event, train the gut to absorb more, and individualise hydration and sodium from real sweat losses. This breakdown covers their approach in our own words, adds our take for matching it to the right client, and turns it into a fuelling plan you can program and rehearse.
By Markus Evers · September 2026 · a Coachway video breakdown
the short version
Precision Fuel & Hydration's case is that endurance fuelling is a trainable performance lever, not an afterthought: work out the carbohydrate-per-hour the event demands, train the gut progressively so the athlete can actually absorb it, and individualise fluid and sodium from real sweat losses. The one thing a coach should do about it: for endurance and hybrid athletes, stop treating fuelling as generic advice - set carbs-per-hour to the demand, build gut tolerance in training, and rehearse the plan before it counts. For a fat-loss client, this isn't the priority.
Precision Fuel & Hydration - Fuel Skool: How much carb do you actually need?
Source: Precision Fuel & Hydration on YouTube - "Fuel Skool: How much carb do you actually need?". Watch on YouTube. We embed the public video and summarise it in our own words; the video, title and channel belong to Precision Fuel & Hydration, and nothing here implies their endorsement of Coachway.
Who is Precision Fuel & Hydration, and why coaches watch
Precision Fuel & Hydration, led by founder Andy Blow (a former elite triathlete and sports scientist), is a company built around personalised endurance fuelling and hydration - sweat testing, carbohydrate strategy, and race-day planning for athletes from age-groupers to professionals. Their educational content is unusually clear about the numbers most amateurs get wrong: how much carbohydrate an effort actually needs, and how to build the ability to take it in. Coaches watch them because fuelling is one of the biggest, most-neglected performance levers for endurance and hybrid athletes, and they treat it as a coachable system rather than folklore. This "how much carb" piece is a clean example, which is the lens this page is written for.
What Precision Fuel & Hydration actually argues (our summary)
This is our summary of the ideas in the video, in our own words - not a transcript. Watch the original for their exact framing and examples.
- 1
Fuelling is a performance lever. Under-fuelling caps endurance performance regardless of fitness - it's a variable to coach, not an afterthought.
- 2
Match carbs-per-hour to the demand. The right intake rises with the duration and intensity of the effort - work it out from the event, not a habit.
- 3
The gut is trainable. Fuelling is often capped by what the stomach can absorb, not what's needed - and that tolerance can be built up progressively.
- 4
Individualise hydration and sodium. Sweat rate and saltiness vary hugely, so fluid and sodium should match the athlete's real losses, not a fixed rule.
- 5
Rehearse the plan. Practise the intended fuelling in training so the gut and the logistics are dialled before race day, not tested for the first time when it counts.
Coachway's take
We think fuelling is one of the biggest free wins in endurance and hybrid coaching, and it's routinely left on the table. A client can train perfectly for months and then have a race unravel in the last hour purely because they took in a fraction of the carbohydrate they needed - and they'll usually blame their legs, not their fuelling. Treating carbs-per-hour as a coachable number, and the gut as a trainable system, turns a mysterious "I blew up" into a fixable plan.
The gut-training point is the one most people miss. Athletes read a big carbs-per-hour target, try it cold on race day, and get sick - then conclude they "can't handle" fuelling. The coaching job is to build the intended intake up gradually across long training sessions, so the stomach adapts alongside the legs. That's a programming task as much as a nutrition one: the fuelling plan belongs in the long-session prescription, rehearsed and progressed, not handed over as a race-morning instruction.
Where we'd add the important caveat: match this to the client's actual goal. Performance fuelling is for endurance and hybrid athletes with long, hard sessions - it's the wrong emphasis for a general fat-loss client, whose nutrition is about overall intake and adherence, not fuelling a two-hour effort. And keep the lane clear: this is training and performance guidance, so clinical GI problems, medical conditions or anything that needs a diagnosis go to a physician or registered dietitian, not the coach.
So our version of their approach is: for endurance and hybrid athletes, set carbs-per-hour to the event's demand, build gut tolerance progressively in training, individualise fluid and sodium from real sweat losses, rehearse the plan in long sessions - and keep everyday nutrition and any clinical questions in their proper lanes.
Put the fuelling plan in the session, not the inbox
Fuelling only works if the plan is attached to the training and rehearsed, so the job is to make it part of the program rather than a stray note. In Coachway you write the fuelling protocol into the long session in the workout builder - the carbs-per-hour target for that effort, the gut-training progression, the fluid and sodium plan - so the athlete practises fuelling every long ride or run, not just on race day. Then how it went comes back through check-ins - energy, GI comfort, whether they hit the intake - so you can progress the gut and dial the plan in with data. The strategy is theirs; the platform keeps the fuelling attached to the training it belongs with.
For the endurance training the fuelling supports, the companion breakdowns on Stephen Seiler on intensity distribution and Joel Jamieson on conditioning cover building the engine you're fuelling.
The endurance fuelling plan (for the right client)
A short template for building an endurance athlete's fuelling into their training. The targets are set from the event and the individual - use it for endurance and hybrid athletes, not general fat-loss clients.
Endurance fuelling plan
| Element | Set it to | Why |
|---|---|---|
| Carbs / hour | Match the event's duration and intensity | The requirement rises with the demand |
| Gut training | Build the intake up over long sessions | Absorption is the real cap; it's trainable |
| Hydration / sodium | Match the athlete's real sweat losses | Sweat rate and saltiness vary hugely |
| Rehearsal | Practise the plan in training, not on race day | Dial the gut and logistics before it counts |
| Right client? | Endurance/hybrid athletes, not fat-loss clients | Match the approach to the goal |
How to use it: for an endurance or hybrid athlete, set the carbs-per-hour from the event, build the intake up across long training sessions so the gut adapts, and match fluid and sodium to real sweat losses. Rehearse it in training. Training and performance guidance only - clinical GI issues or medical conditions go to a physician or dietitian.
ENDURANCE FUELLING PLAN (via Coachway) - build the fuelling into training for endurance/hybrid athletes; rehearse it - CARBS / HOUR -> match the event's duration and intensity | the requirement rises with the demand - GUT TRAINING -> build the intake up over long sessions | absorption is the real cap; it is trainable - HYDRATION / SODIUM -> match the athlete's real sweat losses | sweat rate and saltiness vary hugely - REHEARSAL -> practise the plan in training, not on race day | dial the gut and logistics before it counts - RIGHT CLIENT? -> endurance/hybrid athletes, not fat-loss | match the approach to the goal HOW TO USE: For an ENDURANCE or HYBRID athlete, set carbs-per-hour from the event, build the intake up across long training sessions so the gut adapts, and match fluid and sodium to real sweat losses. REHEARSE it in training, not on race day. Not for general fat-loss clients - match the approach to the goal. Training and performance guidance only; clinical GI issues or medical conditions go to a physician or registered dietitian.
Endurance carb fuelling - FAQ
How many carbs per hour does an endurance athlete need?
It depends on how long and how hard the effort is - the requirement rises with duration and intensity. Short, easy sessions need little to no extra carbohydrate; longer and harder efforts push the useful intake up into the tens of grams per hour, and well-trained athletes doing long, hard events can tolerate and use quite high hourly intakes if they've trained the gut for it. The key coaching point isn't a single magic number, it's matching the fuelling rate to the demand of the session, and building the athlete's ability to absorb what a big effort actually requires. Precision Fuel & Hydration's framing is to work out the target from the event, then close the gap between what's needed and what the athlete can currently stomach.
What is gut training and why does it matter?
Gut training is progressively practising taking in carbohydrate during exercise so the athlete can absorb more without GI distress. The gut adapts like other tissues: an athlete who never fuels in training will get cramps and nausea trying to take in race-level carbs, while one who has gradually trained tolerance can absorb far more. It matters because fuelling is often capped not by what the athlete needs but by what their stomach can handle - and that ceiling is trainable. Practically, you build the intended race intake up over weeks of long sessions, so the fuelling plan works when it counts instead of causing the very GI problems it was meant to prevent.
How do you personalise hydration and sodium?
By recognising that sweat rate and sweat sodium concentration vary enormously between people, so generic hydration advice under- or over-shoots for most athletes. The practical approach is to estimate how much an athlete sweats and how salty their sweat is - through simple field methods or testing - and set fluid and sodium intake to roughly match losses over long efforts, rather than drinking to a fixed schedule. Getting this wrong in either direction hurts performance and can be dangerous at the extremes, which is why it's individualised. It's also why fuelling and hydration are coached together: both are about matching intake to the athlete's real demand.
Is this relevant for general fitness clients, or only racers?
It's most relevant for endurance and hybrid athletes doing long or hard sessions - that's where under-fuelling clearly caps performance and where the carbs-per-hour and gut-training ideas pay off. For a general fat-loss client, this isn't the priority; their nutrition is about overall intake and adherence, not fuelling a two-hour effort, and it would be a mistake to have them practising race fuelling they don't need. Match the approach to the goal: performance fuelling for the endurance athlete, sensible everyday nutrition for the general client. The skill is knowing which client is in front of you. This is training and performance guidance, not medical advice - send clinical GI issues or medical conditions to a physician or dietitian.
More endurance and nutrition breakdowns
- · Stephen Seiler on intensity distribution - building the endurance engine you fuel.
- · NCI on nutrition periodization - matching nutrition strategy to the phase and goal.
- · The full library: fitness creator coaching breakdowns.
Fuel and train the endurance athlete
all guidesStephen Seiler on Polarized Endurance Training (Coach Breakdown)
Dr. Stephen Seiler's polarized (80/20) endurance model, broken down for coaches: keep most work genuinely easy, make the hard work truly hard, and audit a client's intensity split instead of just adding volume.
Read the guideJoel Jamieson on Conditioning (Coach Breakdown)
Joel Jamieson's energy-system conditioning, broken down for coaches: build the aerobic base first, layer a smaller dose of high-intensity on top, on one repeatable weekly template - not random HIIT.
Read the guideNCI on Nutrition Periodization (Coach Breakdown)
The Nutritional Coaching Institute's nutrition periodization, broken down for coaches: stop parking clients in a permanent deficit and cycle planned deficit, maintenance and building phases.
Read the guideFree tools for this: BMR Calculator · Cut Length Calculator · Refeed Day Calculator
Coach fuelling as part of training
Fuelling works when the plan is attached to the session and rehearsed, not sent as a race-morning note. In Coachway you write the carbs-per-hour, gut-training and hydration plan into long sessions and track how it went in check-ins, so you progress the gut with data. Start your 14-day free trial and turn under-fuelled blow-ups into a dialled-in plan.
