Originally Posted by iacas
Really? I think you'd get better odds of the latter than the former. 22 and 18 is a lot of hardware.
Missy Franklin is 17 and won five medals in London; she has time to improve, and could compete in three more Olympics before she's 30. The fact that swimmers have so many opportunities to medal, begin their careers so young, and yet also have the potential to have long competitive careers (Dara Torres won an Olympic medal before I was born, yet just missed being on Team USA this year), I think it's possible for someone to match Phelps' medal count. Maybe not likely, but certainly possible.
In contrast, we probably won't see a marathoner even compete in the 5,000 or 10,000 in the same games (let alone win each event) ever again. The marathon is competed on a much larger scale today than it was 60 years ago, and the training has become much more specialized. Zatopek set Olympic records in all three events in 1952; new Olympic records were set in each of those events in Beijing four years ago. Zatopek's OR's in the 5k and 10k (14:06.6, 29:17.0) are both 1.088 times the current OR's Kenenisa Bekele set in those events (12:57.82, 27:01.17), but the marathon OR has advanced at a much faster pace. Following the rate of progression seen in the 5k and 10k, the marathon record would be 2:11:29, but the late Sammy Wanjiru ran a time five full minutes faster than that in Beijing.
What has caused the marathon record to drop so much is that modern marathoners prepare more and race less than they did even 20 years ago. The US Marathon trials were held in January, and none of the three men who qualified for team USA have raced at any distance since March. And while it's not uncommon to see recreational or regional-level runners do back-to-back races, like running a 10k and a marathon on the same weekend, those runners are not aiming for personal bests, and those feats are unheard of among the elite ranks, where runners are aiming for personal bests in every race.