Is playing traditional jazz hard work?
It depends what you mean by 'hard work'. Sometimes it doesn't feel like work at all. If you have a really good gig, where everything gels and both the band and the audience have a great time, you end up on a high.
But there IS a lot of hard work, both at the gigs and before them. The work involves mastering and storing a lot of music and related information inside your head and also keeping the relevant muscles in shape (fingers, lips, whatever). This becomes increasingly difficult as we age. Obviously a lot of practice is important.
Haven't you noticed too that you can feel very tired after a long gig? That's when you know hard work has been involved.
And don't you find that long gigs leave you feeling very hungry? They drain your resources. My old tuba-playing buddy Peter Jenns (who died in August 2006) always used to say he was starving after a gig and, no matter how late he arrived home, he always had a couple of toasted peanut-butter sandwiches before he went to bed!