The two-hour marathon: who and when?

Whoever breaks 2 h will likely have outstanding running economy and small body size along with exposure to high altitude and significant physical activity early in life. However, neither of these factors nor any specific suite of genotypes appear to be obligatory for a time this fast. Current trends suggest that an East African will be the first to break 2 h. However periods of regional dominance in distance running are not unique to the East Africans: athletes from Finland, Eastern Europe, Australia, and New Zealand have all had extended periods of success at a range of distances. From a physiological perspective, more information is clearly needed on the relationship between VO(2max) and running economy and the influence of running economy and body size on thermoregulation and fuel use.