5k Runner Takes pHastr For The First Time - Then Wins Three Events in a Row
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In a five-week stretch this spring, Whitby's Max Turek did something that quietly tells you a lot about where elite distance running has gone — and where it's still being decided.
April 4: wins the Beneva Spring Run-Off 8K in High Park. April 18: wins the Under Armour Toronto 10K at Nathan Phillips Square in 29:13 — by one second, with three men crossing the line within a heartbeat of each other. May 3: wins the BMO Vancouver Half Marathon in 1:03:28, clear of the field by more than a minute.
Three races. Three wins. All decided not in the easy middle of the race, but in the windows where pH falls and the body decides whether it can keep going.
That's the part of the race we want to talk about.
The race within the race
If you've raced a 10K hard, you know the texture of it. You're not in the V̇O₂ ceiling the whole way. You sit just under threshold for 6 or 7 km, and then somewhere around 8 the pace stops feeling like a pace and starts feeling like a question.
The UA Toronto 10K this year actually built that question into the course. The final kilometre was its own separately timed segment — the UA Velociti Challenge — a sprint to the line from a 9 km mat. Turek won the race by a single second. Whatever he had left in that final kilometre, it was the difference between a paycheck and 3rd place.
The half marathon at 1:03:28 is a different shape — closer to a sustained tempo at lactate threshold rather than a near-V̇O₂max effort — but the principle that decides it is the same. You hold a pace that lives just under the line where hydrogen ion accumulation outruns clearance. The athlete whose body clears H⁺ faster has more pace headroom, longer.
This is the territory bicarbonate operates in. Not the warm-up. Not the cool-down. The window.
Why this window is bicarbonate's window
During hard running, your muscles are leaning heavily on anaerobic glycolysis to keep ATP flowing. The byproduct is hydrogen ions, and a lot of them. As intracellular pH drops, three things start working against you in sequence:
- Glycolytic enzymes — phosphofructokinase in particular — slow down. Your fuel pipeline narrows.
- Calcium handling inside the muscle cell degrades. Contractile force drops even when neural drive is the same.
- The transporters that shuttle lactate and H⁺ out of the muscle (the MCTs) work along a gradient. The more buffered your blood, the steeper the gradient, the faster you clear.
Sodium bicarbonate raises extracellular [HCO₃⁻]. That single change steepens the gradient pulling H⁺ out of the working muscle and into the bloodstream, where it gets neutralized and exhaled as CO₂. The math is simple, the chemistry is faster, and the result is more time spent above the pace your competitors are about to crack at.
The published consensus places bicarbonate's biggest effects on efforts in the 30-second to 12-minute window — which captures the closing kilometres of a 10K and every meaningful surge in a half. Modern research has extended this into sustained near-threshold work and into repeated-effort scenarios, where the question isn't "can you survive one effort" but "can you survive the next one."
That's the closing kick at Toronto. That's holding 3:00/km when everyone else's pace starts to slip in the back half of a half. That's the territory.
The signature of a fast finish
What the lab data shows, and what the courses confirm, is that bicarbonate doesn't make hard feel easy. It moves the line.
In a controlled FTP test we ran with another athlete — Emily, a cyclist, with full gas-exchange measurement — peak V̇O₂ rose 14.9% and peak V̇CO₂ rose 19.0% with bicarbonate vs. without. The disproportionate jump in V̇CO₂ is the chemical signature of the buffering reaction itself: H⁺ + HCO₃⁻ → H₂O + CO₂, exhaled. Mean heart rate rose 11 bpm. Same athlete. Same protocol. Different ceiling.
In a race, you don't see V̇CO₂. You see a one-second gap at the line, or a runner who didn't fade in the last 5 km of a half, or a closing 1 km sprint nobody could match.
Why we built Phastr
Phastr is enteric-coated sodium bicarbonate, dosed and delivered to land at the start of an effort with the buffer already in your blood — without the GI cost that has historically kept athletes off bicarbonate.
The science of NaHCO₃ as an ergogenic aid has been settled for years (the ISSN's 2021 position stand on bicarbonate is unambiguous on it). What hasn't been solved, until recently, is how to take it without it taking you out of the race. Bloating, cramping, urgency — these aren't side notes. They're the reason most athletes who tried bicarbonate ten years ago never tried it twice.
Enteric coating moves the dissolution past the stomach. Same mechanism. Same physiology. Different experience.
The takeaway
Three races, three wins, decided in the window where pH falls. Whether you're hunting a podium or your own PB, the closing kilometres of a 10K and the back half of a half are where buffering capacity stops being a footnote and starts being the answer to a question you've already been asking your body.
Pace held. H⁺ cleared. Race won.
References: Siegler et al. (2016) Sports Medicine Open; Hadzic et al. (2019) J Sports Sci Med; Grgic et al. (2021) ISSN Position Stand, JISSN; Gurton et al. (2024) Eur J Appl Physiol. Race results: Canada Running Series, BMO Vancouver Marathon, Athletics Illustrated.
