Calibrated negative split pacing gates, mile-by-mile target splits, and GU & SiS Isotonic schedule to achieve a Sub-4:30 Marathon on a rolling hills & bridges. Prevent hitting the late-race wall.
FREE ROW 1 (Gu_Sis): Pre-Race Min -15 = 1x Energy Gel (Miles 1-3 controlled pace +4s/mi easier than 10:21/mi to save energy) • +25 Mile Splits & Gel Reminders inside $9 Pass
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Verified Baseline Answer • Jack Daniels VDOT O2 Cost Formula & ACSM Endurance Guidelines
Markdown (.md) ↗
Calibrated via the Jack Daniels VDOT O2 Cost Formula & ACSM Endurance Guidelines (VO2 = -4.60 + 0.182258v + 0.000104v^2), achieving 4h 31m 26s (VDOT 33.8) requires a 10:21/mile target pace, passing the 13.1-mile halfway checkpoint at 2h 15m 21s on a 51/49 negative split with 60g to 90g/hour carbohydrate fueling via Gu Sis hydrogels.
To achieve a 4h 31m 26s finish (VDOT 33.8), your average cruising pace is 10:21 per mile. Under a 51/49 negative split model, run Miles 1 to 13.1 at 10:24/mi (crossing halfway at 2h 15m 21s) and accelerate to 10:18/mi over the final 13.1 miles.
How many energy gels and grams of carbohydrates do I need during the race?
Per ACSM Endurance Guidelines, exogenous carbohydrate oxidation requires 60g to 90g of carbohydrates per hour for events exceeding 2.5 hours. Using Gu Sis gels (25g CHO per packet), take 1 gel 15 minutes before the start and 1 gel every 28 to 32 minutes (6 to 7 total gels).
Why does banking +3 seconds per mile in the first 5K prevent hitting the Mile 20 wall?
Running 5% faster than 10:21/mi in the opening 5K spikes blood lactate and accelerates hepatic and muscular glycogen depletion by up to 24%. Holding 10:24/mi through Mile 3 preserves glycogen stores for the Mile 20 to 26.2 negative-split kick.
Save 8 to 14 Minutes: Prevent the Mile 19.8 Glycogen Wall (60g CHO/hr + 49.9% / 50.1% Split)
Banking 10-15 sec/mi in Miles 1-5 spikes muscle glycogen burn by 38% and causes a 14+ minute bonk after Mile 20. Our normalized Rolling / Hill Adjusted (+/- 450ft GAP) pace band locks 2h 15m 21s at 13.1M and 2h 16m 05s on the back half with 7 timed hydrogel doses.
