Simon,
The design is nice and crisp, and reflects well on the site's area of interest - making folks lean. Navigation seems a bit slow, but that may be related to some of the issues already mentioned. It was't terrible compared to other site's I've visited, though, but it woud benefit from the tune-ups suggested.
I was able to ping the site, just a quick 10 count result:
Pinging www.workoutbox.com [216.177.71.9] with 32 bytes of data:
Reply from 216.177.71.9: bytes=32 time=68ms TTL=114
Reply from 216.177.71.9: bytes=32 time=73ms TTL=114
Reply from 216.177.71.9: bytes=32 time=67ms TTL=114
Reply from 216.177.71.9: bytes=32 time=70ms TTL=114
Reply from 216.177.71.9: bytes=32 time=81ms TTL=114
Reply from 216.177.71.9: bytes=32 time=73ms TTL=114
Reply from 216.177.71.9: bytes=32 time=66ms TTL=114
Reply from 216.177.71.9: bytes=32 time=68ms TTL=114
Reply from 216.177.71.9: bytes=32 time=68ms TTL=114
Reply from 216.177.71.9: bytes=32 time=67ms TTL=114
Ping statistics for 216.177.71.9:
Packets: Sent = 10, Received = 10, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 66ms, Maximum = 81ms, Average = 70ms
So, it's a bit better state side than from the UK, but I would expect that considering you are hosted in the USA.
Now, all of that being said, I really shouldn't have looked at your side while at lunch, eating my fried tenderloin, and fried onion rings. Now, I'm going to have to get to your site at home, and start with the rookie program. I think it's a nice looking site, and folks will find it beneficial. Good job!
Phil - Mission, KS, USA