Uphill vs. flat

If you want to complete the hilly 10k in the same time as the flat 10k, then the second effort will be T+x.

Stated another way, if you ride the hilly 10k with effort T, then your time/speed will be slower than the first ride.

i think what he is saying is if he normally rode 10KM on the flats, would it be the same as riding 5 KM Uphill, and also 5KM downhill (the uphil portion compensating for the lack of efford on the downhill)

My answer: i have no idea... but i would guess it would be comparable.

foild1 said:

My answer: i have no idea... but i would guess it would be comparable.

Yep, they're comparable --- the comparison is posted above. 😉

Keep in mind that discussions of distance and effort are meaningless without considering the time/speed aspect. That's the reason for the 2-part answer above.

You seem to be confusing effort with speed. You can ride a flat 10K and a hilly 10K at precisely the same effort (power). But, your elapsed time will be significantly longer for the hilly 10K because you will lose more time on the uphill segments than you will gain on the downhill segments at a constant power. The same would apply to an out/back course in the wind. Intensity of effort is completely independent of hills or wind. But, the resulting bike speed is dramatically affected by hills and wind. Hills and wind don't require a higher intensity of effort, we just tend to do it.

I'm going to say - man you got some time on your hands... 🙂

Seriously - though I have read somewhere 1000 feet of elevation is "like" a full mile in effort. So even if the up and the down balance, there will be the added effort of the rise left over. You buy that for a dollar?

HR

Let's say that elevation is not significant (500 feet) and that I want to ride the 10K at the same average speed.

Let say that I ride the 10k flat at 20km/h average

If I rode the 10k hilly ride at the same 20 average km/h (faster on the downhill than uphill), will the effort required to do the hilly ride be the same, less or more than the flat?

Aramis7 said:

Let's say that elevation is not significant (500 feet) and that I want to ride the 10K at the same average speed.

Let say that I ride the 10k flat at 20km/h average

If I rode the 10k hilly ride at the same 20 average km/h (faster on the downhill than uphill), will the effort required to do the hilly ride be the same, less or more than the flat?

See post #2. I answered your question the first time and others have answered it since.

Aramis7 said:

Let's say that elevation is not significant (500 feet) and that I want to ride the 10K at the same average speed.

Let say that I ride the 10k flat at 20km/h average

If I rode the 10k hilly ride at the same 20 average km/h (faster on the downhill than uphill), will the effort required to do the hilly ride be the same, less or more than the flat?

As frenchyge and RD said, the total work effort required for a hilly ride will be higher than for the flat 10K, if both are ridden at an identical 20km/hr avg.

Just playing with the numbers, believe cruising at 12.4 mph on a level only requires about 70 watts of power. In that case, doing your flat 10K in 30 minutes would require 70 watts for 1800 seconds, for 126kjoules of work. If you add one 500 ft hill, and you and your bike together weigh say 90kg, then climbing 500 ft (~150 meters vertical gain) by itself would add 132 kjoules of work to the course, which exceeds the total energy expended to complete the flat course at 12.4 mph.

Or, looking at the power required, if the hill is a 10% grade, and you climb it at 5 mph, you'll need to put out around 200 watts for over 11 minutes to get to the top. Again, you can see that product of power and time (energy) just for the hill exceeds the total (70 watts x 30 minutes) needed for the flat course.

Some real numbers. Assume 300 watts constant, flat 10K riding on hoods. The time for a 165 pound rider with 20 pounds of bike and clothing will be about 16 minutes, 45 seconds with no wind.

For 5 km at a 10% uphill grade, the time will be about 24 minutes 30 seconds at a constant 300 watts.

Descending at a constant 300 watts, 5 km take about 4 minutes and 15 seconds.

Total time up and down: 28 minutes 45 seconds -- considerably longer.

Interesting side note, on a closed out and back uphill - downhill course, the fastest possible average speed over the course is twice the average ascent speed.

Ok I'll Bite I think you would loose some of the energy built up climbing the hill when you start hitting the air at higher than normal speeds coming down this resistance would rob you of speed unless you pushed your effort up a notch going up and/or coming down. I think hill climbing is also forcing a less efficient pedaling effort with lower cadence and out of the saddle bike swaying further robbing you of speed.

Aramis7 said:

HI everyone, I've had this quasi-hypotethical question since long ago, I hope you can shed some light.

Let's say that I do a 10k flat training session, that requires an effort "T".
Now let's say that I change that 10k flat for a 10k hilly ride, with 5k uphill, and a 5k downhill.

Question:
Will the hilly ride require same "T" effort to complete? less? more?.

I don't want to make this a matter of hill gradient, I'm just curious as whether a harder, shorter uphill and zero-effort downhill is the same as flat ride (constant effort).

What do you think?

Cheers