Out of curiosity, I compared two mp4 versions of your clip of Hannah Storm 5/18/12, from
WWoW via Hotfile and
Youtube.
Identical attributesDuration: 01:49.
Resolution: 1,280x720.
Frame rate: 29.97 fps.
Audio codec: mp4a.
Different attributes, original vs. YoutubeSize: 123 MB | 28.4 MB (4.33:1 ratio).
Video codec: mp4v | avc1.
Bit rate: 9,443 kbps | 2,028 kbps (4.66:1 ratio)...
aha.
So, Youtube's compression (along with the video codec change) seems to be the main reason for the large file size difference.
As long as there is no fast movement on screen... say, working out, dancing, leg crossing... 2,000-ish bit rate, combined with HD 720p, should be enough to do your sexy newsworthy subjects justice.