Athlete
Lance Armstrong
Cyclist (seven Tour de France titles, later stripped)
All evidence
2 records, newest first. Strength changes with age and weight class, so check the date and context before you compare.
2007
- Marathon2:46:43
“He returned to New York City a year later, improving his time to 2:46:43.”
2:46:43. His marathon best in this source.
2006
- Marathon2:59:36
“Armstrong competed in the 2006 ING New York City Marathon, completing the race in 2:59:36.”
Race result reported in the race press release. 2:59:36.