Mark <[email hidden]> wrote in message news:<[email hidden]>...
Quoted message said:That's funny because my dad just e-mailed me the same thing about trying the Withlacootchee State
Trail. Also another thing I always wondered about... If I ride 50 miles of flat road or 25 miles
of up hill then 25 miles of down hill...... Don't they both end up using the same amount of
power/excersize/whatever?
Most people who have ridden courses with substantial hills would probably not ask that question,
because a person's subjective perception of how hard a course is goes up with the amount of
climbing. There's no way not to know hills are harder.
It might seem, intuitively, that the downhills would let you rest enough to make up for the climbs,
but they don't. On a steep climb, the bicyclist's speed slows to about half (or less) the speed he
can ride on the flats. Watch your speedometer and you'll see this is true. Which means that if the
uphill stretch is one mile long, it takes about twice as long as one mile of flat riding. You would
have to ride down the corresponding downhill in zero seconds to keep the total riding time the same
as on a flat course of the same total length. But you will take some time to get down the hill. You
might even pedal a bit and do some work on the downhill.
Another way to look at it is to consider where your climbing energy goes. You put all that work into
lifting yourself against gravity. Then when you roll down the other side at a high speed, you
release that stored energy, but where does it go? It all gets lost as heat, some when you brake for
the turns, and some as your body plows through the air (aerobraking). You have air drag whenever you
ride, of course, but at higher descending speeds the air drag goes up enormously. Try pedaling up to
50 MPH on the flats and see what I mean. Not even the world's best sprinters can generate enough
power to do that on a single bike, without a motorized pacing vehicle to provide a draft.
If you have a downhill steep enough and straight enough to let you coast at 50 MPH, you are
dissipating gravitational energy into the air at a furious rate.
This is why a hilly course is faster if all the downhills are gradual, and straight enough not to
require any braking. You only speed up a little on a gradual downhill, so the gravitational energy
moves you a farther horizontal distance, rather than being so quickly dissipated as waste heat as
happens on a steep downhill.
Another factor adding to climbing fatigue is the nonlinearity of fatigue response. A cyclist working
at 90% of his maximum capacity will fatigue far more quickly than when he works at just 50%. If you
measure your effort with a heart rate monitor, you can see your heart rate ticking its way up on
long steep climbs, even though you downshift and slow down. On a steep uphill, it's difficult to
slow down enough to prevent your heart rate from increasing. You would have to use a tiny gear ratio
and ride so slowly you'd have difficulty staying upright. There's no practical way to avoid working
hard on a climb, except maybe to hang onto a passing car.
Basically this means grinding up a steep hill will "take a lot more" out of a cyclist than riding a
much greater distance on flat roads at a moderate pace, even if the long flat course consumes more
total calories.
I see this all the time when I lead group rides. Even less-experienced cyclists will cruise along at
a decent pace on the flats, chatting happily with each other, until I take them up one substantial
hill. After that, the ride is like a death march as they take miles of flat roads to recover enough
to resume their conversations. Total climbing is clearly a significant component of course
difficulty, especially when the climbing gets concentrated into a few long steep uphills. A course
with a lot of small rollers could have a lot of "total climbing," but it might not be much harder
than a flat course if the maximum hill amplitude is small. For a climb to "count" it must be long
enough to slow you down, force you into a low gear, and make you really feel the grade for a while.
With small rollers your momentum might take you most of the way over.
It's obvious that climbing is harder than riding on the flats. Granted, a sufficiently motivated
cyclist can ride hard on the flats by going fast, but few recreational cyclists work hard enough on
the flats to make the effort compare to hills.
The upshot is that if a cyclist is riding with the intent to gain fitness, a hilly course will be
harder without requiring the cyclist to monitor his effort as carefully. This can be a factor when
you are riding alone and don't have faster riders to pace you. You can climb a lot of hills and
insure a hard workout without having to get too meticulous about how hard you are working. Working
hard on the flats generally requires unimpeded courses, too. If you ride in an area with lots of
stop signs and traffic, maybe uphills will be the only places where you can really work hard without
smashing into something.
-- Daniel Mocsny