strenuous

I made a strenuous effort to reach the top of the mountain.

A strenuous task, but feasible, thanks to our relieving each other.

That would be a strenuous job for father, who was fat.

Many attempt to hike it in a single day, even though it is long and strenuous.

Strenuous exercise generates lactate—the molecule that makes overworked muscles burn.

Yeah. So first of all, limit your time outside — especially strenuous activities like exercise.

It's what allows you to perform strenuous physical tasks, like climbing a mountain.

Yoga and meditation. If strenuous exercise doesn't suit your mojo then we have an alternative.

Usually this shift is small, but if combined with beta-blockers or kidney issues, strenuous exercise can lead to hyperkalemia.

It was a long and strenuous walk in the heat and the humidity to get back.