Login
Subscribe
Subscribe
Magazine
All Issues
All Articles
Old School Ultras
Articles
Reviews
Training & Racing
Health & Nutrition
Race Reports
News & Notes
Ultra Running 101
Podcast
UltraRunners Of The Year
Training Plans
Events
Upcoming Races
By State
Map View
Results
Latest Results
Runner Search
All Time List
Shop
Back Issues
Digital Back Issues
Hats
Stickers
Odds and Ends
Cart
About
About UR
Columnists
Staff
Ambassadors
Advertising
Contact
Change of Address
Editorial Submissions
Articles by Kirk Cureton
What Limits Our Performance in an Ultramarathon?
Gordon Warren
Kirk Cureton
Phillip Sparling
June 1989
Features