Method

Fitness is estimated with the Daniels & Gilbert VDOT model (Oxygen Power, 1979), cross-checked against Riegel's power law (American Scientist 69:285–90, 1981) at exponent 1.06. Training load uses the Banister impulse-response model with exponential TRIMP weighting: CTL is a 42-day and ATL a 7-day exponentially-weighted mean, form (TSB) their difference. Intensity distribution is three-zone by percentage of observed maximum heart rate (188 bpm, recorded 3 March 2026). Efficiency factor is metres per minute per heartbeat, restricted to aerobic runs of 4 km or more. The race projection is a 200,000-draw Monte Carlo over current fitness, projected gain, a half-marathon durability penalty and race-day execution noise. Source data: 116 running activities from 1 August 2025 to 14 August 2026, pulled from Strava. Resting heart rate is not exposed by the connector, so TRIMP assumes 50 bpm; the CTL trend is insensitive to ±8 bpm at under 5%.

References

Casado A, Hanley B, Santos-Concejero J, Ruiz-Pérez LM. World-class long-distance running performances are best predicted by volume of easy runs and deliberate practice of short-interval and tempo runs. J Strength Cond Res 2021;35(9):2525–31. doi:10.1519/JSC.0000000000003176
Seiler KS, Kjerland GØ. Quantifying training intensity distribution in elite endurance athletes: is there evidence for an "optimal" distribution? Scand J Med Sci Sports 2006;16(1):49–56. doi:10.1111/j.1600-0838.2004.00418.x
Hoogkamer W, Kipp S, Frank JH, Farina EM, Luo G, Kram R. A comparison of the energetic cost of running in marathon racing shoes. Sports Med 2018;48(4):1009–19. doi:10.1007/s40279-017-0811-2
Bosquet L, Montpetit J, Arvisais D, Mujika I. Effects of tapering on performance: a meta-analysis. Med Sci Sports Exerc 2007;39(8):1358–65. doi:10.1249/mss.0b013e31806010e0
Nielsen RØ, Parner ET, Nohr EA, Sørensen H, Lind M, Rasmussen S. Excessive progression in weekly running distance and risk of running-related injuries. J Orthop Sports Phys Ther 2014;44(10):739–47. doi:10.2519/jospt.2014.5164
Minetti AE, Moia C, Roi GS, Susta D, Ferretti G. Energy cost of walking and running at extreme uphill and downhill slopes. J Appl Physiol 2002;93(3):1039–46. doi:10.1152/japplphysiol.01177.2001
Midgley AW, McNaughton LR, Wilkinson M. Is there an optimal training intensity for enhancing the maximal oxygen uptake of distance runners? Sports Med 2006;36(2):117–32. doi:10.2165/00007256-200636020-00003
Jeukendrup A. A step towards personalized sports nutrition: carbohydrate intake during exercise. Sports Med 2014;44(Suppl 1):S25–33. doi:10.1007/s40279-014-0148-z
Ganio MS, Klau JF, Casa DJ, Armstrong LE, Maresh CM. Effect of caffeine on sport-specific endurance performance: a systematic review. J Strength Cond Res 2009;23(1):315–24. doi:10.1519/JSC.0b013e31818b979a
Mah CD, Mah KE, Kezirian EJ, Dement WC. The effects of sleep extension on the athletic performance of collegiate basketball players. Sleep 2011;34(7):943–50. doi:10.5665/sleep.1132

Rebuilt automatically after every logged run and each morning at 06:00 ET. Revision 2.0 · generated 2026-08-15 19:51 · not medical advice.