​Ed. note: Toni Reavis will call Sunday's Austin Marathon, live on FloTrack, and wrote the following this week with the marathon on the brain.

Marathon running and prize fighting are two of the world's most primal forms of athletic competition. For top contenders, major marathons are a lot like prizefights in that both involve inflicting and withstanding pain, while requiring up to three months in preparation for a single competition. Of course there are many differences in the two combative sports, one being the size of the competitive arena.  In boxing it is generally a ring 20 feet square, give or take, while a marathon spans many miles of city streets. Another difference is in the number of contestants--boxing is purely mano a mano, while runners compete in a pack.  And finally there is a difference in how the combatants are categorized.

While running is one-size-fits-all, boxing, wrestling, and UFC all determine opponents based on weight categories so that like fights like. In Olympic boxing the category limits are:

-light flyweight, 108 pounds (49 kg)
-flyweight, 112 pounds (51 kg)
-super flyweight, 115 pounds (52 kg)
-bantamweight, 118 pounds (53.5 kg)
-super bantamweight, 122 pounds (55 kg)
-featherweight, 126 pounds (57 kg)
-super featherweight, 130 pounds (59 kg)
-lightweight, 135 pounds (61 kg)
-super lightweight, 140 pounds (63.5 kg)
-welterweight, 147 pounds (67 kg)
-super welterweight, 154 pounds (70 kg)
-middleweight, 160 pounds (72.5 kg)
-super middleweight, 168 pounds (76 kg)
-light heavyweight, 175 pounds (79 kg)
-cruiserweight, 200 pounds (91 kg)
-heavyweight, unlimited

Studies have suggested that it is the thin lower legs of the East African runner, an active rural lifestyle at high altitude, and a drive to succeed to better their lives that best explains their separation in terms of performance from the rest of the world's population. Whatever the difference, a look at the top marathons of all time (as of Dec. 31, 2016) shows that every sub-2:04 marathoner is from East Africa, all but two from Kenya, and of those most are members of the Kalenjin tribe. Age listed is at the time of fastest performance.

Dennis Kimetto (30), Ken. - 5'7", 121 lbs (171 cm/55 kg) - 2:02:57, Berlin 2014
Geoffrey Mutai (29), Ken. - 5'7", 119 lbs (169 cm/54 kg) - 2:03:02, Boston 2011
Kenenise Bekele (34), Eth. - 5'3", 121 lbs (160 cm/55 kg) - 2:03:03, Berlin 2016
Eliud Kipchoge (31), Ken. - 5'6", 126 lbs (167 cm/57 kg) - 2:03:05, London 2016
Moses Mosop (25), Ken. - 5'6", 135 lbs (167 cm/61 kg) - 2:03:06, Boston 2011
Emmanuel Mutai (29), Ken. - 5'4", 115 lbs (162 cm/52 kg) - 2:03:13, Berlin 2014
Wilson Kipsang (34), Ken. - 5'11", 137 lbs (182 cm/62 kg) - 2:03:13, Berlin 2016
Patrick Makau (26), Ken. - 5'7", 121 lbs (169 cm/55 kg) - 2:03:38, Berlin 2011
Stanley Biwott (30), Ken. - 5'9", 134 lbs (175 cm/60 kg) - 2:03:51, London 2016
Haile Gebrselassie (35), Eth. - 5'4", 119 lbs (161 cm/54 kg) - 2:03:59, Berlin 2008
Average: 5'6", 124 lbs (168 cm/56.5 kg)

Now consider the great Americans, past and present, in the event.

Galen Rupp (29) - 5'11", 134 lbs (181 cm/61 kg)
Bill Rodgers (31) - 5'9", 128 lbs  (175 cm/58 kg)
Frank Shorter (25) - 5'9", 134 lbs (175 cm/61 kg)
Alberto Salazar (23) - 5'11", 141 lbs (180 cm/64 kg)

Internationally athletes.

Toshihiko Seko (30), Jpn. - 5'7", 137 lbs (169 cm/62 kg)
Carlos Lopes (38), Por. - 5'5", 121 lbs (165 cm/55 kg)
Rob de Castella (29), Aus. - 5'11", 143 lbs (180 cm/65 kg)
Steve Jones (30), Gbr. - 5'10", 137 lbs (178 cm/62 kg)
Rod Dixon (33), Nzl. - 6'1", 154 lbs (186 cm/70 kg)

Currently, of the top 100 marathon performances ever run (and I include Boston in this list of reasons for historical significance), 63 have come from Kenyan-born athletes, 33 from Ethiopian, 3 from Moroccan, and one from an American-born runner (Ryan Hall, 2:04:58 from Boston 2011, in 55th position, which is the top non-East African performance on the list).

So dominant have the two top East African nations become that once-widespread international fields have been largely erased in the 21st century.  Formerly robust running nations like Mexico, Italy, Portugal, Spain, Korea, Germany, Russia, Australia, New Zealand and Brazil are nowhere to be found among the lead packs of the world's top marathons anymore.

Famed American marathoner of the 1970s Bill Rodgers once questioned whether there should be a separate division for athletes born at altitude, as all evidence points to a distinction between such athletes and those born closer to sea-level in terms of performance capabilities.  Does the same hold for size?

Should consideration be given to introducing new prize money weight divisions to widen the appeal and return a more broadly based international participation to races (if not lead packs) of the world's top marathons?  There is already an unofficial Clydesdale division.  Should there be others, too, officially?

Lightweight: <140 (63.5 kg)
Middleweight: 140 - 170 (63.5 kg - 72.5 kg)
Cruiserweight: 170 - 200 (72.5 kg - 90 kg)
Heavyweight: 200+  (90 kg)

As always, just asking.