Dentist here,

Seems like you suffered a vertical root fracture if the diagnosis of the tooth is nonrestorable and the Tx prescribed is an extraction. If the ext appt is on Wed and your race is on Saturday I'm fairly confident you should be fine to race on race day given that you follow the post operative instructions and don't deviate in any way which could either interrupt healing or cause a dry socket (not fun).

1) soft foods for the first 3 days is generally recommended. I like to tell my patients to drink smoothies by spoon (straws are prohibited during the first few days)
2) no drinking through straws as stated above. Using a straw can dislodge the clot that is forming over the socket and prevent healing
3) no spitting. If you have to spit, drool out the corner of your mouth.
4) no smoking as this can directly cause dry socket.

Again, this is my recommendation based on a highly motivated triathlete patient that's committed to racing. My professional advice is definitely give yourself a 1 week buffer.

Other than that. Goodluck!