nomadthethird
more issues than Time mag
definition of fast twitch muscle fibers
essentially - slow twitch muscles are for aerobic, fast twitch are for sprinting, lifting weights, anything requires short sharp bursts of intense activity, which is what most sports are, aside from distance running/cycling/etc.
as far as that bit about sodium, yeh I really dunno. the bit about muscles doesn't really explain why they'd have more (or more effective) fast twitch muscles, just that on average they do.
this I don't know about. surely there are detrimental effects of living under stress but I wouldn't be surprised if affluent people - at least in certain countries, like the States - actually have a higher rate of heart disease. overly rich diet, sedentary lifestyle, etc.
Interesting... so essentially some striated muscles are meant to respond more quickly on the electrochemical level--or twitch more frequently? Which means they can be useful for different tasks.
But it would explain why people with more muscles survived the ships--people with more muscle tissue would have had more protein to live on through the harsh conditions (because their body would've started eating their muscles), and this would have left them better off immune-wise and starvation-wise.
And yeah, there was a time when richer meant more heart disease, but these days its generally recognized that obesity and related problems hit impoverished people harder, because impoverished people are more likely to eat cheap, refined carbohydrates. Obesity is also more lethal in poorer folks, I'm pretty sure.
Edit: I forgot about cardiac muscle tissue, too. I was counting that as smooth but it's not.