Sport Today

Uhhh..excuse me, trained marathon runners dont run 12 mph, extremely talented one
and trained ones do. Thats about a 2:11 marathon and I personally dont know many
people who can run that fast.

AS I said earlier, it depends.

Cycling on smooth tarmac in flat terrain, 12 mph is slow and real easy.
What I average 12 mph on is on rough road in very hilly terrain. It's not
the same thing at all.
Today I did a 55m spin with a friend in pretty hilly terrain, with maybe
1000m or more of climbing at an average of 13.3 mph, on touring bikes,
with poorish road surfaces. This was done at what felt like a medium
comfortable pace and I could have done it a fair bit faster, but I feel
pleasantly tired and will be ok for more tomorrow. Goin hard I could do
this spin at maybe 16mph at the moment, but I would be knackered for the
next couple of days. What good would that do?

My max ever spin was 215m in one day at 14.2 mph. 2 years ago.
I was tired for a week afterwards.
My fastest was 10 years ago, 100 mile solo TT, out and back in 4-46.
I wouldn't dream of trying something like that now.

I agree that my estimates are for ideal, flat conditions, however, the
absolute values aren't the important point.  By increasing speed by
approximately 67%, say from 12 to 20 mph, caloric expenditure rises by
approximately 600%.  It requires increasingly more power (and energy) to
increase speed at the margin (I think this is called an exponetial
function, its not a linear relationship).  What all this means to us
riders is that by riding faster we are burning disproportionally more
calories per unit time.  If you have limited time or don't want to spend
a lot of time riding (some of us have alternate lives) its much more
time efficient to ride fast.

Jack

Ken Kifer replies:
It's just as easy to figure calories as it is watts or foot pounds per
second; in fact, it just takes a simple equation to covert watts to
calories.  The real problem are these two: 1) Are we talking about input
or output?  The output is easy to measure; however, due to the
wastefulness of the body, many more calories of energy must be burned
than it takes to produce a given output.  Plus, our bodies are not all
the same. 2) Are we talking about the same conditions?  In riding on
flat ground, wind resistance is the most important factor, thus local
wind conditions and streamlining determine the speed at a given output.
Then we have hills, the rider's weight, the rotating weight of the
wheels and other factors to consider.  If one cyclist consistantly
averages 20 mph on his rides and another averages 17, we still do not
know which cyclist is the more fit or which was working harder.

--
How should one plan for a touring trip?  Is it possible to make
touring bags?  Where can a cyclist find free camping?
URL: http://www.kenkifer.com/bikepages/

I would suggest that you go back and read. Being a diabetic, it's worth
my life to understand these things. I'd suggest you look at the
relationship of fat and carb energy supply at various energy output
levels. Then look at the effects of various types of training on those.

I agree that what's important is energy in vs energy out. Unfortunately,
if you train for carbs, you cannot keep going without them, and the
supply is small. So, you have to eat virtually as many calories as you
burn. If you train for fat burning, and you only replace the amount of
calories in the carbs used and your input will be less.

Plus there's a training effect, and long, relatively low intensity
exercise (we are talking 60-70% of max here) does result in better
mobilization and utilization of fat. To get there, you have to use up a
good proportion of your sugar stores before you even get into the
training phase. What this means is that you will need to replace less
carbs as you get in better fat burning shape.

Any exercise burns some fat. The lower the intensity, the greater the
proportion burned. A good compromise for long distance cycling is 60-70%
of your max aerobic output.

That was a separate subject, responding to a undercurrent this thread
has had for some time. If anything, racers may even be less concerned
about their long term health. They are focused on winning, and will make
lots of compromises with their health if they think it will help.

Any of these measures are difficult to measure accurately. But, they are
not near as difficult to calculate, at a lower level of confidence, but
still useful for planning purposes. For me, when I calculate my energy
usage and account for the amounts I get in my diabetes control planning,
I come out correct in my *** sugar levels.

Ok, from "Bicycling Science" page 39, figure 2.4, interpreted from the
graph. Crouched Racing cyclist 300 calories/hour at 12 mph; Upright
tourist 450 calories/hour at 12 mph. That, of course is flat riding on
smooth surfaces. Around here, you have to add about 500'/hour climb at
12 mph. To say nothing of wind, rough roads and so on.

Easy walking does work out at about 150 calories/hour, depends on what
you call easy. This also from "Bicycling Science" page 37 Table 2.1.

Comparing what's on the two above, twelve mph equates somewhat on level
ground with walking in excess of 5 mph, hardly easy walking. Though I've
gone nearly that fast with a backpack on my back in the right terrain (downhill).

Use Power, Watts, Calories, they all relate by simple multipliers,
whatever, a non-issue. Actually the program I wrote for my own use gives
me Calories, Calories/min, Watts and Horsepower. All as put into moving
the bike. But, since I use it to plan my diabetes diet and medication, I
pay most attention to Calories.

Walt