Why 90% of Race-Day Supplements Fail—Here Are 7 (Besides Caffeine) That Deliver
Estimated read time: 3.2 minutes (about as long as it takes to realize your BCAA powder is just expensive chalk). 😉
Hey Performance Nerds! Jonah here. 🤓
Research shows 90% of marathon supplements are worthless. Only 7 have real evidence.
(And yes — caffeine is still the #1 race-day booster. These are the other tools worth knowing about.)
Here’s what the science actually says works:
🔥 The $0.10 supplement that drops your core temp by 0.5°C (nope, not caffeine)
⚡ Why sodium bicarb is GI roulette but worth it for hills
💧 The heat-proof combo that adds 2kg but might save your race
🥤 Why beet juice fails when temps climb above 75°F
❌ Which powders are basically flavored chalk
(Augie once ate my sodium bicarb. The betrayal in his eyes still haunts me.)
🚨 Quick heads up:
The strength bundle we've been developing with 10+ PhDs is almost ready—and you'll want to get on the waitlist for early access pricing.
We're talking $400+ of strength, nutrition, and marathon plans for just $47. But only if you're on the waitlist when we launch.
This is the same system that helped 100+ pro athletes, now engineered specifically so it won't wreck your legs during marathon training.
P.S. Once we open to the public, it jumps to $197. Your call.
🧬 Performance Sponsors:
🚀 Train Harder. Recover Smarter.
SiS—the same science-backed fuel trusted by Olympic marathoners—is now sponsoring Marathon Science.
From hydration mixes to recovery tools, every product is backed by real performance data and built for serious athletes like you.
🚀 Power Your Pace with Stryd
Stryd — the running power meter trusted by serious athletes — is now an official performance sponsor of Marathon Science, delivering real-time pacing precision so you can train smarter and race faster.
💡 See this week’s full Stryd training tip at the end of this newsletter.
🔥 1. Taurine: The Heat-Crusher Nobody Talks About
What it does: Improves endurance and helps with cooling. Studies show it may lower core temp by ~0.5°C and increase sweat rate (≈13–27%).
Best for: Hot races (≥70°F / 21°C)
Skip if: Cool races under 50°F
Protocol: 2–3 g (≈50 mg/kg) 1–2 h pre-race. Cheap, low GI risk.
⚡ 2. Sodium Bicarbonate: GI Russian Roulette (But Worth It for Hills)
What it does: Buffers hydrogen ions (H+) that cause muscle burn. Once thought of as a sprinter’s tool, new evidence shows bicarb may also help marathoners — reducing hyperventilation in the heat and keeping blood flowing to the brain.
Translation: Even steady marathon pace can feel easier, especially on hills or in hot races.
Race-day value: The big trade-off is GI distress, which is common. Some athletes lower the risk with capsules, split doses, or smaller amounts. If you’ve tested it and tolerate it, there’s little downside to racing with it.
Best for: Hilly courses, hot marathons, or races with frequent surges.
Skip if: Sensitive stomach, first marathon, or never tested in training.
Protocol: 0.3 g/kg, 1–3 h before racing. Always test in training first.
💧 3. Creatine + Glycerol: Heat-Proof
What it does: Increases body water storage for better thermoregulation. May lower HR and core temp in heat. Trade-off: ~1–2 kg water weight gain.
Best for: Runners who overheat, hot/humid races, ultras.
Skip if: Chasing a PR on cool/hilly courses, never had heat issues.
Protocol: Creatine 3–5 g/day for 4+ weeks (no loading needed). Glycerol 1.2 g/kg + fluids 2–3 h pre-race. Always test the combo in training.
💦 4. Glycerol Alone: Hydration Without the Performance
What it does: Expands plasma volume, helping hydration and sweat rate. Performance effects? Inconsistent.
Best for: High sweat rate runners, ultras in the heat.
Skip if: Racing cool conditions or looking for speed.
Protocol: 1–1.2 g/kg + 20–25 ml/kg fluids, 60–150 min pre. GI risk is high — practice first.
🥤 5. Nitrates (Beetroot): Works Until You’re Fast or It’s Hot
What it does: Can reduce oxygen cost of running by 2–3% in recreational athletes. But benefits fade in elites and hot races.
Best for: Sub-elite marathoners (3:30+), cool races, flat courses.
Skip if: Racing in heat or already highly trained.
Protocol:
Loading: 6–12 mmol/day for 3–7 days pre-race
Acute: 6–12 mmol (≈70–140 ml beet juice) 2–3 h pre
Avoid mouthwash — it kills the bacteria that convert nitrates.
💊 6. Beta-Alanine: Sprint Finisher’s Insurance
What it does: Raises muscle carnosine, buffering acid during 1–10 min bursts. Great for 800m, less so for marathons.
Best for: Final kicks, steep hills, or track workouts.
Skip if: You run even splits or don’t want 4+ weeks of loading.
Protocol: 3–6 g/day, split doses for 4–8 weeks. Expect harmless tingling. Minimal marathon benefit.
🌿 7. Polyphenols: The Wild Cards
What they do: Plant compounds with mixed evidence. Oligonol may lower temp, curcumin may protect the gut in heat, blackcurrant shifts fuel toward fat (not helpful at marathon pace).
Best for:
Oligonol → hot races when nothing else works
Curcumin → runners with GI issues in heat
Skip if: Cool races, tight budget, or looking for guarantees.
Protocol:
Oligonol: 100–200 mg, 30–60 min pre-race
Curcumin: ~500 mg/day for 3 days pre (use enhanced-absorption forms)
Blackcurrant: don’t bother
❌ Supplements That Don’t Work
Save your money on these “performance” duds:
BCAAs – your diet already covers it
Tyrosine – “mental fatigue” claims don’t hold up
Glutamine – immune hype, no performance payoff
Probiotics – gut health, not race speed
Colostrum – overpriced milk protein
Ginseng – fine in tea, not in your race kit
Beta-glucan – “immune booster” with no race-day effect
👉 Think of these like carbon insoles in flip-flops. Useless for marathoners.
📊 Quick-Reference Table
Supp | Benefit | Heat Effect | How to Use | Evidence |
|---|---|---|---|---|
Taurine | Boosts endurance + cooling | ✅ Strong cooling | 2–3 g (50 mg/kg), 1–2 h pre | Moderate–High |
Sodium Bicarb | Buffers fatigue, helps surges | ⚠️ Lowers RPE in heat, high GI risk | 0.3 g/kg, 1–3 h pre (test first) | High (short bouts), Moderate (heat) |
Creatine + Glycerol | Water storage → heat tolerance | ✅ Lowers temp & HR | Creatine 3–5 g/day × 4 wks; Glycerol 1 g/kg + fluids, 2–3 h pre | High (thermo), Mixed (perf) |
Glycerol | Expands plasma volume | ⚠️ Reduces heat strain (inconsistent perf) | 1–1.2 g/kg + fluids, 1–2 h pre | High (hydration), Low (perf) |
Nitrates | Improves economy in rec runners | 🚫 Blunted in heat/elites | 6–12 mmol, 2–3 h pre or 3–7 d load | Moderate (rec/cool), Low (heat/elite) |
Beta-Alanine | Buffers sprints | 🚫 No heat/ marathon effect | 3–6 g/day × 4–8 wks | High (sprints), Low (marathon) |
💬 One last thing before you go.
After the NFL, I wasn’t sure if obsessing over performance science still mattered — until I started building this community.
Your training goals brought that fire back.
So if you’re testing any of these supplements, struggling with fueling, or just curious how others are experimenting — hit reply. I read every message and would love to hear what’s working (or not) for you.
🧪 Quick Survey — Help Shape the Future of Sports Nutrition
Next week I’m meeting with one of the leading sports nutrition companies to talk about what athletes really want. Before I sit down with them, I want your input.
This is your chance to influence the products, flavors, and fueling strategies brands bring to runners, triathletes, and hybrid athletes like you.
It’s just 5 quick questions (under 1 minute) — and I’ll share the results back with this community.
🏃♂️ Stryd Training Tip — Run Faster with Stronger Springs
Leg Spring Stiffness (LSS) is your body’s “energy return system” — how efficiently your legs store and release energy each step. Boosting stiffness can improve running economy by 4–8% — the same edge you’d get from $250 super shoes.
Why it matters:
Less bounce, more speed: Lower vertical motion and quicker ground contact = better efficiency.
Stryd measures it: Track LSS, ground contact time, and vertical oscillation to see progress.
Train it: Heavy calf isometrics and plyometrics strengthen tendons, teaching them to snap back with every stride.
💡 Bottom line: Build stiffer springs and you’ll run faster at the same effort — in any shoe you own.
Don’t forget: You + Science = AWESOMENESS 😎
Yours in science,
Jonah
P.S. - We have a crew of 17,450+ nerds here who are running FAST using science.
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