burny hat geschrieben:Ist das so? Es werden ja nicht Läufer absolut oder individuell verglichen, sondern relativ, also die Zeiten z. B. des 100. Finishers von Lauf "kalte Temperatur" mit der des 100. von Lauf "warme Temperatur". Dabei müsste der Effekt des "Einbrechens" eigentlich eliminiert sein. Von allen Finishern werden ja nur die ersten 300 heran gezogen.
Vermutlich brechen bei den höheren Temperaturen auch von den ersten 100 mehr ein. Also meinetwegen 10 bei "kalte Temperatur" (Optimisten gibt's immer) und 30 bei "warme Temperatur" (dreist geschätzt). Dann sehen die Zielzeiten der ersten 100 bei "warme Temperatur" unnötig langsam aus.
Den Rest sehe ich genauso, Bernd.
Bin noch mal durch den Artikel drüber, und meine, dass folgendes vielleicht noch aufgezeigt werden sollte hinsichtlich der Diskussionen hier:
0) Massig Daten: "Marathon race results were obtained from seven different races including Boston (Boston, MA), New York (NY, NY), Twin Cities (Minneapolis/St. Paul, MN), Grandma's (Duluth, MN), Richmond (Richmond, VA), Hartford (Hartford, CT), and Vancouver (Vancouver, Canada) … a complete analysis of the above races included the past 36, 29, 24, 23, 6, 12, and 10 yr, respectively."
1) Warum nur die jeweils ersten 300 Läufer? "many marathons did not keep consistent records beyond the 300th place until the mid-1990s"
2) Das Wetter: "Weather parameters were averaged for the duration of each race."
3) Die einzelnen Temperaturen zeigen, dass im Mittel Tdb = WBGT:
(Tdb - Twb - Tg -
WBGT, "mean", alles in °C)
WBGT-Bereich 6-10: 8.0 - 4.8 - 19.2 -
8.0
WBGT-Bereich 20-25: 21.9 - 17.6 - 37.6 -
21.9
4) Männer = Frauen: "Moreover, when female data are compared against those from a population with similar finishing times (25th-place finisher), the pattern of change with increasing WBGT seems similar, suggesting no apparent differences between genders"
5) Warum "slower runners are affected more by a rising WBGT than faster runners"? Vermutung der Autoren (BMI/Gewicht wird nicht erwähnt):
"This slowing could be attributable to the fact that each population of runners is spending more time exposed to the environmental conditions. For example, the 300th-place runners spend approximately 50 more minutes (~38% more time) exposed to the elements than the elite men.
Also, slower runners tend to run in closer proximity to other runners, which has been estimated to cause more than three times the physiological heat stress compared with running solo in identical weather conditions (4,6). The increase in heat stress arises from a small net reduction of long-wave radiative heat losses (R + C), which amounts to an approximate 2°C increase in ambient temperature. More importantly, convective heat loss is reduced 50% as a result of entrainment of air (4,6).
Differences in fitness relative to physiological potential could also contribute to differences in performance times and ability to cope with increasing heat stress."
"If you want to become a better runner, you have to run more often. It is that easy." - Tom Fleming