Bicycling: physiological differences between women and men?

[zut]

My wife and I went out mountain-biking last weekend. When I bike, I tend to shift gears a lot to get the right power match for going up hills and so forth. My wife, on the other hand, tends to stay in the same gear, or at least do a lot less shifting. When I mentioned this difference, she says she thinks that a woman's pelvic tilt makes it easier for her to transmit more power to the pedals while leaning forward (like going up a steep hill). A man doesn't have that advantage. How much truth is there to this?

[CookingWithGas]

Although there is a difference in hip geometry I think that doesn't offer a benefit to women. In fact, according to Trek engineers, the opposite is true:

There are several major differences in how men and women sit on a bike. The most obvious and most discussed is pelvic structure. A woman’s hips are wider, and the bony protuberances we all sit on, called ischial tuberosities, are also wider apart.

In addition, a man’s pelvic structure allows him to roll his pelvis forward on the saddle and lean forward aggressively. On a woman, this hurts. The result is that a woman sits on a bike seat with her pelvis in a more upright position, making it difficult to lean forward.

I would say that your wife would still ride more efficiently by shifting gears more, regardless of any baseline differences offered by hip geometry.

Footnote: In doing a Google search for this topic the #3 hit on "man woman hips bicycle" was an ad for the Love Swing. <blush>

[mack]

I've never heard of that. Which doesn't mean anything, by the way.

Shifting-wise the two of you could just have different styles. You might be more into maintaining a cadence while she might just want to power up the hill.

I ride road bikes with my sister sometimes. She has a triple chainring and a 9-speed cassette while I have a double chainring and a 7-speed cassette and downtube shifters. I tend to find an optimum gear for whatever we're doing and stay there as long as I can. She shifts a lot more often.

[Kiting Illini]

I am with mack on this one. I own a bicycle shop and know lots of cyclists. According to the hearsay evidence I have, the primary physiological factor dealing with pedal cadence is musculature. IANAD so I don't have all the technical terms, but humans tend either to 'fast twitch' or 'slow twitch' musculatures.

Those with 'slow twitch' are generally stronger in terms of peak output for short periods of time, and tend to prefer higher gears and 'grinding' up hills. 'Fast twitchers' tend to be stronger in terms of overall stamina and prefer to gear down and spin.

[casdave]

I think in this case it comes down to cadence timing flexibility.

Whenever you make a pedal stroke at a steady speed, you put power in at certain times during the revolution, do it right and you wind up being extremely efficient.

When the going gets a little harder, your timing goes out just a smidgeon, so you end up putting power in at a less optimum time(generally too soon and much closer to top dead centre where there is no useful work carried out), usually you need to delay the timing a bit and put the power down for slightly longer.

As the going gets easier you make your pedal effort slightly later, but this is much easier to correct.

You might think that by being able to move your pedal effort to suit the terrain would actually be more useful, but unfortunately we are not built that way, although there is some flexibility in our ability to produce produce power.

Humans are endurance animals, which means lots of repetitions at fairly low power.When we work in this way we go go on for ever, but if we go on to use power and strength then endurance drops off very rapidly as the load increases.

Cyclists who ride seriously tend to spin the gears at a certain speed if possible, changing gears to maintain that cadence, which of course means that the speed then changes.
The idea is to keep your strength in reserve for the time when it really matters.

Riders who pedal along in one high gear for all occasions will rarely have much endurance(unless it's a good rider using fixed gears)

If you ride in a gear too low then you tend to tire yourself out too, it's a question of finding the best middle between pedalling furiously and grinding it out on huge chainrings.