Does thinner air make you faster ?

[Panoramix]

Hello all,

It took me 20 years of marriage to convince Mrs P that cycling in Colombia was a good idea....

So a couple of weeks ago I managed to borrow a road bike and went on 2 rides. I always stayed at an altitude between 2500m and 3000m... The climbs were hard even if I had been staying in Colombia for 2 weeks but on the flatish and downhill portions I was flying! Bike was a racing bike 1 or 2 sizes too small for me (so my position was very "aggressive") with "semi deep" rims and geared for "tough Colombian legs".

I can't make up my mind, was it me (unlikely ;-) ), the euphoria of enjoying Colombian roads for the first time, the bike or the air thinner due to altitude ? Has anybody experienced "flying conditions due to altitude" before ?

[Mr Larrington]

Yes, Eddy Merckx 

[philip]

Yes, thinner air is faster. Your ability to produce power goes down, due to limited oxygen, that makes you slower. Your aerodynamic drag also goes down, due to thinner air, that makes you faster. Which one of these dominates depends on how long and hard an effort you are making and how fast you are going. The world hour record was set at a moderate altitude of a few hundred metres, the world 1km record (less than a minute) was set at high altitude. Temperature also has an effect as warmer air is thinner.

[Mr Larrington]

TV's Nice C Boardman noted a couple of years ago that instead of going to $HIGH_ALTITUDE for track record attempts it's cheaper and simpler to go to Manchester and crank the heating up.

[T42]

Altitude builds up your haematocrit. It's why Boulder, CO is a great cycling centre.  When I was up at the Great Divide, at 4350 metres - higher than the summit of Mont Blanc -  there were cyclists arriving every few minutes.

[Lightning Phil]

Altitude builds up your haematocrit. It's why Boulder, CO is a great cycling centre.  When I was up at the Great Divide, at 4350 metres - higher than the summit of Mont Blanc -  there were cyclists arriving every few minutes.

That is somewhat lower than the height of Mont Blanc

[T42]

Altitude builds up your haematocrit. It's why Boulder, CO is a great cycling centre.  When I was up at the Great Divide, at 4350 metres - higher than the summit of Mont Blanc -  there were cyclists arriving every few minutes.

That is somewhat lower than the height of Mont Blanc

Right enough, I was shifting the 8 one notch to the right. Still pretty high for cycling, though.

[Cudzoziemiec]

Thinner air makes you faster, as do thinner tyres, thinner bodies – but for some reason not thinner hair???

[Lightning Phil]

Thinner air makes you faster, as do thinner tyres, thinner bodies – but for some reason not thinner hair???

Thinner hair makes you more aero

[yoav]

You have to spend some time at altitude for it to have an effect on your haemoglobin, at least several weeks, ideally, your whole life. But, there’s always a but, this raised haematocrit is only really useful at sea level. This is because the partial pressure of oxygen in the air is lower at altitude meaning there is less oxygen for your body to absorb. Haemoglobin saturation, as measured with a pulse oximeter would be lower than at sea level. However, at altitude the body produces more of something called 2,3 DPG which allows haemoglobin to release more oxygen to the muscles. But this disappears when you return to sea level. So you win some and lose some.
Here endeth the physiology lesson. 😉

[IanDG]

Yes, Eddy Merckx 

...and Moser.

[Panoramix]

Thanks all, this is what I thought.

I could definitely feel the difference...

As for the lack of oxygen, the climbs were definitely harder, I had to walk some very steep bits that I might have just managed at sea level.

[bhoot]

TV's Nice C Boardman noted a couple of years ago that instead of going to $HIGH_ALTITUDE for track record attempts it's cheaper and simpler to go to Manchester and crank the heating up.

Several years ago I went to an interesting talk about designing a fast (record breaking) velodrome (the London one) where one of the engineering team explained all about getting the temperature high for the elite events but not bothering for other general usage of the place.

[Panoramix]

TV's Nice C Boardman noted a couple of years ago that instead of going to $HIGH_ALTITUDE for track record attempts it's cheaper and simpler to go to Manchester and crank the heating up.

Several years ago I went to an interesting talk about designing a fast (record breaking) velodrome (the London one) where one of the engineering team explained all about getting the temperature high for the elite events but not bothering for other general usage of the place.

Somewhere high under the equator must be pretty fast then (heat + altitude! )....

[rogerzilla]

Yes, Eddy Merckx 

...and Moser.

Moser had some extra "training aids", as did Merckx (probably to a lesser extent).

[PaulF]

Yes, Eddy Merckx 

...and Moser.

Moser had some extra "training aids", as did Merckx (probably to a lesser extent).

Just a different sort of high

[Mr Larrington]

TV's Nice C Boardman noted a couple of years ago that instead of going to $HIGH_ALTITUDE for track record attempts it's cheaper and simpler to go to Manchester and crank the heating up.

Several years ago I went to an interesting talk about designing a fast (record breaking) velodrome (the London one) where one of the engineering team explained all about getting the temperature high for the elite events but not bothering for other general usage of the place.

Somewhere high under the equator must be pretty fast then (heat + altitude! )....

A few track records have been set in La Paz, Bolivia.

[LittleWheelsandBig]

Pilots will tell you that hot, high and humid conditions don’t give much lift. The same conditions mean less wind resistance for cyclists.

[Lightning Phil]

Acclimatisation period is roughly 11 x altitude in kilo metres.  Thus at 4,000 metres it’d take you approx 44 days for your output vs. internal effort to match anything you could do at sea level before heading there.

[Asterix, the former Gaul.]

I went to school with someone who came from a very high altitude South American country. He looked odd in Surrey because he had a barrel-like chest.