How PODIUM's Algorithm Works

Saturday morning: 14-mile run, Z3 effort, 84°F. PODIUM's engine runs four numbers and prescribes 60 g/h of carbs and 1,075 mg/h of sodium. The audit drawer shows why: research target = 60, capacity = 85, sport ceiling = 120, safety floor = 20. min(60, 85, 120) = 60. Floor didn't bind. Done.

That's the whole algorithm. Four constraints in, one prescription out, mapped to whatever fuel you're carrying that morning.

The math is simple. The bookkeeping (tracking inventory, doing live arithmetic at mile 18 with your blood sugar tanking) is what's impossible to do manually. That's the part PODIUM does for you.

Two inputs anchor everything: your current capacity (the grams per hour your gut can reliably absorb today) and your race-day target (the rate your goal demands).

Capacity is a continuous number, not a tier. You set it during onboarding and it adjusts as you gut-train through PODIUM's state machine. Two binary toggles refine it:

• Gut-trained lifts your sport ceiling from 90 g/h to 120 g/h. It's a self-report toggle, not something the algorithm infers. Flip it once you've actually built capacity past 90.
• Custom Mode bypasses the constraint model entirely. The engine prescribes your stored capacity directly, with the safety floor as the only override. This is the off-ramp for athletes who already know their number.

Your race-day target comes from your goal: distance plus expected effort. PODIUM resolves that to a specific g/h target on the home screen. The gap between your current capacity and your race-day target IS your training journey, and that's what the gut-training state machine is closing, one qualifying session at a time.

For every workout you log (duration, intensity, sport), PODIUM compares four numbers and picks one to prescribe.

1. Research target. What your duration and effort demand, from a 6-gate × 3-tier table built on the dose-response and substrate-utilization research.
2. Your capacity. What your gut can absorb today.
3. Sport ceiling. The upper bound (90 g/h untrained, 120 g/h gut-trained, same for both running and cycling).
4. Safety floor. The gate-keyed minimum on long sessions (20 g/h above 60 min, 30 g/h above 90 min). It overrides when the smallest of the first three would leave you bonking.

The first three compete; the smallest wins. The floor steps in only when it has to. The full breakdown of what each constraint is doing lives in How Many Carbs Per Hour.

Smallest wins. Floor protects.

The Plan tab shows the resolved prescription as a single number. The audit drawer underneath surfaces all four constraints and tells you which one was binding. Transparency is intentional. You should know why the engine prescribed what it did, especially when the binding constraint is your own capacity (which is the algorithm telling you the path forward is gut training, not pushing through GI distress).

Sodium runs as a parallel calculation, not a function of your carb intake. Endogenous gut sodium already supplies SGLT1 demand at every carb rate PODIUM recommends, so there's no carb-coupled bonus to apply. The full mechanism breakdown is at Sodium Isn't Just for Cramps.

Your sodium baseline comes from your sweat profile (light / moderate / heavy sweater) per sport. From there:

• Heat scales sodium on a five-tier curve. Cold (<59°F) reduces it 25%, Cool (59–72°F) is baseline, Warm (72–82°F) adds 25%, Hot (82–91°F) adds 50%, Very Hot (>91°F) adds 75%.
• A 1500 mg/h hard cap sits at the top, regardless of inputs. Heavy sweater on a very hot day can otherwise compute above what's tolerable at the gut.
• Gate 0 coupling: when carbs prescribe at 0 g/h (short workouts), sodium also goes to 0. The two move together at the bottom of the duration curve.

You get one combined recommendation in the Plan tab, not two systems to manage.

Before your workout, you tell the app what fuel you're carrying. Which gels, how many, what's in your bottle. Your actual inventory.

The app maps that inventory against your carb and sodium prescriptions for the session, then builds a minute-by-minute fueling script for that specific workout. The output is plain language. "Take one gel now." "Half a pouch now." "Sip your bottle." No mental math required.

The timing follows the 20-minute cycle covered at The 20-Minute Pulse. First cue at minute 15. Every 20 minutes after that: 35, 55, 75, 95.

Inside each cycle, the engine handles four edge cases:

• Catch-up cap. If you missed a cue, the next dose can be up to 1.5× the standard pulse (1.25× in heat above 82°F or after hour 3). The engine refuses to go higher because your gut backs up faster than you can outrun.
• Surplus rule. If you've banked a full dose worth of surplus from earlier cues, the next one is skipped. 50–99% over means a half dose. Never skipped twice in a row.
• Deficit reset. If your shortfall gets too big to recover safely (bigger than 2× your hourly target, or bigger than 1× your hourly target with more than 60 minutes since the last dose), the engine writes off the deficit and resumes the normal schedule. You can't fix a race-ending deficit by stuffing gels.
• Product snap. Instead of telling you "take 23 grams now," the engine rounds your prescription to a real fuel quantity from what you're actually carrying. One gel, half a chew, two sips. No abstract gram counts.

The audio cue speaks the result, not the math.

Press start.

Every 20 minutes you hear an audio cue telling you what to take. Not a generic beep. A specific instruction based on the script the app already built and the inventory you logged.

No mid-run math. No checking your watch. No trying to remember whether that was your second gel or your third.

The algorithm did the planning before you started. The audio cues handle the execution while you're moving. You just run.

Everything in this article, you could do yourself.

• Build a spreadsheet that compares the four constraints for each workout.
• Track your gut capacity and update it after every long run.
• Look up your sodium baseline by sweat profile and scale by temperature.
• Set watch timers at 15, 35, 55, 75…
• Do the math on every gel label.
• Track inventory in your pockets and bottles.
• Remember what you've eaten and what's still owed.

Some people will. Most won't, because the bookkeeping breaks at mile 18 when your blood sugar is doing its own work.

The honest claim PODIUM makes is not that the math is hard. It's that the bookkeeping is impossible to do while running.

That's the whole product. The algorithm handles the planning. The audio cues handle the execution. You just run.

Download PODIUM. Free on the App Store.

Four constraints in. One prescription out. A script wrapped around your actual fuel. Audio cues that handle the execution.

You tell the app who you are, what you're doing, and what you're carrying. It tells you what to eat and when, every 20 minutes, until you're across the line.

The engine is the part you don't think about. That's the point.

// FREE RESOURCE

The First Marathon Fueling Protocol

The exact fueling blueprint to execute your first 26.2 miles with zero guesswork.

• •Carb & sodium guidelines
• •Race week and race day fueling timeline
• •Gut training program

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