It is an undeniable truth that as we age we slow down, but from what age this begins and at what rate do we slow has been the subject of much research.
We do not begin to slow down until our early to mid-30s, and the three primary physiological mechanisms that cause us to slow down are well understood. (1)
35-year-olds tend to show peak endurance performance (6) however ultra marathon events favour athletes with experience so outcomes often skew towards athletes in their early 40s.
The rate of slowing is initially quite gradual at less than 1% per year through your late 30s.
Stabalises at around 1% per year through most of your 40s and into your 50s. (2)
Gradually increasing at more than 1% per year in your 60s.
The rate of slowing increases more rapidly thereafter and by your 70s is more like 1.5% before slowing greater than 2%/y in your 80s (3)
Women tend to slightly close the gap to their male counterparts gradually over time. (4) But not by much.
The distance of the event does not appear to change the rate of slowing. Eg a 41y/o will be about 5% slower over 5km, and roughly 5% slower over 100km, and 5% slower for all distances in between. (5)
(1) Tanaka H, Seals DR. Endurance exercise performance in Masters athletes: age-associated changes and underlying physiological mechanisms. J Physiol. 2008 Jan 1;586(1):55-63. doi: 10.1113/jphysiol.2007.141879. Epub 2007 Aug 23. PMID: 17717011; PMCID: PMC2375571.
(2) Lepers R., Stapley P.J., and Cattagni T. 2017. Age-related changes in endurance performance vary between modes of locomotion in men: an analysis of master world records. Int. J. Sports Physiol. Perform. 17: 1–12.
(3) Knechtle B, Kohler G, Rosemann T. Study of a European male champion in 10-km road races in the age group >85 years. Proc (Bayl Univ Med Cent). 2010 Jul;23(3):259-60. doi: 10.1080/08998280.2010.11928630. PMID: 20671823; PMCID: PMC2900979.
(4) Ravara B, Gava P, Taylor MJ, Pond AL (2019) Statistical analysis of master world records: surprisingly minor gender differences of aging performance decay. Physiother Res Rep 2: DOI: 10.15761/PRR.1000125.
(5) Alan Jones (2014), Age grading running races.
(6) Zingg, M., Rüst, C.A., Lepers, R. et al. Master runners dominate 24-h ultramarathons worldwide—a retrospective data analysis from 1998 to 2011. Extrem Physiol Med 2, 21 (2013). https://doi.org/10.1186/2046-7648-2-21
