Time to get technical for a little bit: let’s talk about muscles. Now it doesn’t matter if you’re into sports or weights or nothing at all (stupid sexy Flanders). You need muscles. To live. (And if you would prefer not to strain your eye muscles on sciencey mumbo-jumbo, feel free to skip to the TL;DR!)
Now there’s a few fields of thought with regards to muscle types and groups, and they call it different things and interpret the findings in weird and wonderful ways. Generally, what most people can agree on is that voluntary muscle (a.k.a. skeletal muscle) falls into two categories: slow twitch and fast twitch.
Slow twitch muscle is a very oxygen-rich muscle type and is rife with capillaries for profuse blood supply, hence it’s alternative name “red” muscle. This muscle type is aerobic in nature and thus carries lots of oxygen and can sustain activity for long periods of time.
Fast twitch muscle is the more anaerobic of the two, and it can generate quick and powerful bursts of energy at low oxygen costs (anaerobic kind of means without air). This means it requires a lower oxygen supply in the short term but it also fatigues rapidly. It has a paler hue compared to slow twitch, resulting in the name “white” muscle, although the actual colour of it is far from white. Little twitchy mammals, such as the epitome of twitchiness Mr. Squirrel, have a large proportion of fast twitch that gives them their lightning bursts of fidgety speed.
Right, I think that’s enough biology for one lifetime. You’re still here? Interesting. Now, how does all this tie in with relatively regular life as an athlete? If you’re into endurance sports such as marathon running, then chances are you’ve got a greater proportion of slow twitch muscle. On the other hand, if you bench regularly, then your upper body is going to be chock full of fast twitch muscle! Simple, right?
TL;DR – Slow twitch: aerobic & long-lasting; fast twitch: anaerobic & short bursts.
Don’t worry, I’m not here to expound on the goodness of either type of muscle, or even sell you some exercise regime for the low, low price of a dollar per minute per second per second (no wait, that’s too many derivatives). I’m here to talk about how working to achieve a certain ratio of fast to slow twitch muscle can help you focus towards getting to your goal.
The table above is a somewhat unverified (oh, am I not supposed to say that?) estimate of the amount of slow twitch muscle you will find in people who frequently perform a particular path of sport or exercise. I’m truly curious about how they measure the ratio of different muscle fibres in a living (I hope) person’s body.
Another comparison that I can’t put numbers to is the difference in muscle types between men and women. It is generalised that men tend to possess a larger proportion of white, anaerobic muscle in their bodies, while women have more red, aerobic muscles. This has been postulated as to why women tend to float better than men in water, due to their lower specific gravity. Perhaps their body shape plays a part too. Wink wink.
It would seem like I would be biased toward red muscle, since my favoured activities would desire and require a greater quantity of salubrious, aerobic muscle. However, it has been observed that white muscle fibres have a much better ability to grow and increase in mass compared to their leaner brethren. So if you’re aiming to bulk up them guns or want a shorter road to a firmer build, then focus on short burst exercises that target your anaerobic muscles. Activities like weight-lifting and resistance training should give you results a lot faster than cycling for long periods.
Of course, ultimately you have to work out for yourself which types of physical exercise are best suited for your needs, as certain things work better for some. And no money back guarantees, thank you very much.