If you want to run a PR time in the marathon, it's very
important to run equal halves. In fact, over the years many athletes, elite
and non-elite, have demonstrated that the ideal scenario is to run the first
half of the race slightly slower than the last half. When you start slowly you
allow your body to adjust to the pace and the exertion, which leaves you with
enough reserves to run the second half as quickly as the first, or EVEN FASTER!
NEGATIVE SPLITS MAKE A POSITIVE DIFFERENCE
The top men and women in the 2002 Boston Marathon admirably
demonstrated the advantages of running negative splits (the second half run
faster than the first). The lead men ran a very strategic race, which resulted
in a half-marathon split time of 1:05:21. At the half-way point there was a
lead pack of approximately two dozen runners that included the defending
champion, Lee Bong-Ju of Seoul, Korea, Silvio Guerra from Ecuador, and Rogers
Rop from Kenya, a relative youngster at the age of 26, who was running only his
second marathon. Rop ran the second half in 1:03:41, and won the race with a
time of 2:09:02. Even on the difficult point-to-point course, with major hills
in the second half, Rop was able to run negative splits, which resulted in a
win. The second place finisher, Kenyan Christopher Cheboiboch (another
youngster, 25), also ran 1:05:21 for the first half and came back with a 1:03:44
for the second.
The defending women's champion, Catherine Ndereba, returned
in 2002. Besides the world record holder Kenyan, there were strong runners
from China,
Ethiopia, and
Japan. Two Kenyans, a Chinese
runner and an Ethiopian runner passed the halfway point in 1:10:43. Shortly
after the Newton
hills, one of the Kenyan athletes, Margaret Okayo, pulled ahead of Ndereba to
win in 2:20:43, breaking the previous women's record by just over a minute.
Okayo ran the second half in 1:10, nearly a minute faster than the first.
Ndereba, who finished second, also ran the second half faster in 1:10:29.
PACING PRODUCES PR'S AND WORLD RECORDS!
Ethiopia's
Belayneh Dinsamo held the world marathon record of 2:06:50 for ten long years.
He set the record by running nearly exact splits of 4:50 per mile for the entire
26 miles. His second half split time was only ten seconds slower than the
first half. Then in 1998 Ronaldo da Costa from Brazil ran the first half of
the Berlin Marathon in 1:04:42, and followed that with an almost unbelievable
1:01:23, for a new world record of 2:06:05. He ran arguably the fastest second
half marathon in history. No male runner has duplicated the 3:19 differential
since. The amazing Khalid Khannouchi broke the 1998 record in 1999 by running
a 2:05:42 (1:03:07 first half, followed by a 1:02:35 second.) Then in 2002 he
broke his own record in London with a 2:05:38, running nearly perfectly
even splits for both halves.
Like the men, the women's marathon world record had stood
for many years (14) before it was broken in 1999 when Kenyan Telga Loroupe ran
2:20:43, beating Norwegian Ingrid Kristensen's record by nearly a minute.
Loroupe ran the second half of her record-breaking race just a minute slower
than the first. 2001 saw the women's record broken twice in one week.
Japanese champion Naoko Takahashi took the women's record under 2:20 for the
first time in history in Berlin, running splits of 1:09:48 and 1:09:58
for a sensational 2:19:46. Only six days later, Catherine Ndereba lowered that
time to 2:18:47, running split times of 1:10:15 and 1:08:32 in Chicago. Then in the
2002 London Marathon, first-time marathoner Paula Radcliffe from
Great
Britain ran a remarkable 2:18:56, good enough
for the win, the fastest first time marathon, and the second fastest marathon
finish ever by a woman. She also achieved another milestone: a second half
split nearly equal to Dinsamo's record-breaking time. Radcliffe ran the second
half in 1:08, nearly three minutes faster than the first.
THE PHYSIOLOGY INVOLVED IN RUNNING NEGATIVE
SPLITS.
Marathon runners use fats and
carbohydrates as fuel; fats are burned only aerobically, carbohydrates are
burned both aerobically and anaerobically. Carbohydrates are the fuel of
choice, however they will last only about 18-20 miles in even the most gifted
runners who start the race fully loaded. This is why you must run slowly
enough initially to stay "aerobic", so you'll use a little bit of fat as fuel.
By burning this fat on the flame of carbohydrate, you spare some carbohydrate
for use later in the race. But if you get excited and go out at a pace that
can't be sustained, you will become anaerobic and use too much carbohydrate
(stored muscle glycogen), which will cause you to reduce your pace and fall
behind.
According to distance running researcher Dr. Dave Costill,
aside from the limits imposed on runners by heredity and the ability to train
hard, diet is the single most important factor the athlete can manipulate if he
or she is going to succeed at the marathon distance. Pre-race diets high in
carbohydrates allow you to store muscle glycogen and to use the stored glycogen
late in the marathon. If you haven't consistently eaten a high carbohydrate
diet (65% or even more in the days just prior to the event) you will not be
fully tanked up with stored glycogen reserves. The marathon is raced at about
80-95% or more of maximum oxygen capacity (VO2max). At this intensity the
predominant fuel is carbohydrate, which must be stored if you want to maintain a
steady pace for the entire marathon.
Also, most distance runners have a predominance of slow
twitch fibers in their lower legs. These fibers prefer to function
aerobically, and they use both fats and carbohydrates as fuel. However, all
runners have some larger muscle fibers in the same muscles called fast twitch
fibers that, although they prefer to function anaerobically, also at times use
aerobic fuels from fats and muscle glycogen. When the runners in the lead pack
surge, they use some stored muscle glycogen in their fast twitch fibers as the
pace increases. Surges don't last long, since runners often are running above
their lactate threshold, which promotes faster depletion of glycogen reserves
and a corresponding earlier collapse or slowdown.
Truly elite runners are capable of running at a very high
percentage (approximately 80-95%) of their VO2max for the entire marathon
distance. This unique ability is partly genetically endowed, but to a great
extent it's developed over time through consistent training and a high
carbohydrate diet. Elite athletes also develop an extraordinary sense of
pacing by repeatedly practicing pacing during training and shorter races (from
10Ks to the half-marathon). The sense of pace pays off during the marathon
when they can sense any slight pacing disruption and react to it. They teach
their bodies how to run at such a fast, yet aerobic effort by specific training
(such as practicing surges and longer sustained intervals), frequent racing at
shorter distances, and eating significant amounts of carbohydrates after
training and racing to replenish muscle glycogen.
MIMIC THE PROS AND REAP THE BENEFITS!!!
-
Practice running at marathon goal pace during some of your
training runs.
-
Practice surging during your training runs
until you feel comfortable with the disruptions in your pace.
-
Practice longer, sustained intervals (mile repeats, for
instance) at marathon goal pace.
-
Practice running faster than marathon goal
pace in shorter races from 10K to the half-marathon.
-
Eat a diet that's consistently composed of
65% carbohydrates. Eat even higher amounts in the few days prior to your race.
-
Start your race at a pace that's
comfortable so you won't deplete your glycogen stores early on.
-
Gradually pick up the pace and run the
second half as fast, or faster, than the first.
Al Morris, Ph.D., FACSM, ran his best race off even pacing
in 1978 with a 2:44. He ran several others, but came nowhere near his best
time. He retired with 36 marathons under his belt!
http://www.howtobefit.com/elite-runners.htm
