Why would you be unable to run forever without your muscles giving
out?

Well The body converts glucose to energy which produces lactic acid as a by-product. As that builds up in the muscles, it begins causing cramps and fatigue as a signal to stop. So you have to stop when you reach the lactate threshold. And Over the course of a sustained run at half-marathon pace or faster, the amount of energy (and thus oxygen) needed to maintain that pace gradually inches upward. Over the course of 10-20 minutes, your oxygen consumption can drift upward by as much as 25 per cent, making it progressively harder for you to Hold up.

I Hope this Helps! May I Have brainliest? <3

answer-

the statement that f(x) = |x+a| + b has exactly one x-intercept is sometimes correct.

solution-

it solely depends on b, whether the function will have one or two or zero x intercept.

this plot of the given function, f(x) = |x+a| + b will be the basic absolute value graph i.e v shape, with vertex translated to (-a, b), instead of origin.

1-   if b is zero, the graph will have exactly one x-intercept, at x= -a

2- if b is positive, the whole graph will be above the x-axis, hence it will have no x-intercepts.

3- if b is negative, the graph will be below the x-axis, hence it will have two x-intercepts.

∴ the statement is sometimes true.