Strength

Remember from the intensity page: Work is Mass x Distance, so if you want to move heavier mass you need to be stronger.  Power is work divided by time, so again the stronger you are the more work you can do, and if you can lift 100 pounds you could throw a 10 pound ball further than if you could only lift 50 pounds.

I will leave you with some quotes from Mark Rippetoe:

Strong people are harder to kill than weak people, and more useful in general.
— M. Rippetoe
The vast majority of women cannot get large, masculine muscles from barbell training. If it were that easy, I would have them.
— M. Rippetoe
Does a bigger motor slow the car down? No. But a bunch of junk in the trunk does.
— M. Rippetoe
Only people willing to work to the point of discomfort on a regular basis using effective means to produce that discomfort will actually look like they have been other-than-comfortable most of the time. You can thank the muscle magazines for these persistent misconceptions, along with the natural tendency of all normal humans to seek reasons to avoid hard physical exertion.
— M. Rippetoe