Might sound like a crazy question but it came up in conversation with friends last night.
For me it would have to be the ‘Can Can’! 10 of us performed it in a show when I was still dancing. Great fun to dance but the whole thing is very long, very energetic, and we had to do two encores! Can still do a high kick - but would probably have a heart attack if I tried to do the whole thing now!!
Rowing bow in a coxed 8. This was many years ago when I was a member of a Thames based rowing club and although training and racing was exhausting, it was also exhilarating and thoroughly rewarding. Being ambidextrous, I decided on being the bow oarsman as being right at the front, I would not be constantly down wind from the rest of the sweaty crew 
Exercising at the gym, with other members, oh boy did we have some fun, we were in stitches a lot of the time, I used to love out running some of the youngsters on the treadmill,
I never forget trying to out run a gentleman who was in his 80s I was told, he out ran me, …he’d been running since a lad.
I walked up Whernside in the Yorkshire Dales with members of my keep fit group a couple of years ago. It was a very hard walk for me - I’m used to walking on flatter surfaces - but it was such fun and exhilarating when we reached the summit. I was also able to raise some money for the Crohn’s Society due to being sponsored by friends and family to do the walk. The drinks in the pub at the end of the walk were a bonus!
A caving trip with a few friends. It is not a cave open to just anyone, as it is a SSSI (Site of Special Scientific Interest.) And it’s a reasonably tough system, so you have to show you have the capability to do it & do it as a club.
The cave is in south Wales & if I remember correctly. The deepest in the UK. There were some great sumps, that is 100% underwater sections & it’s hours of hard, wet exercise. And if I remember correctly we spent around 13 hours down there & saw just a fraction of the 10’s of miles of passages.
Oh wow, I would have loved to have a go at that, what a fun memory 
Are you ever tempted to have a little go again in private?
I think that’s brave, I’m far too claustrophobic to do that
My most recent exhausting thing was o have a go at paddle boarding
I’ve always wanted to try it so I got over the being too old thing and had a go, even though most of the rest of the class were a third of my age
The hardest thing was getting from kneeling to standing because if you’re anything like me you need to grab hold of something to pull yourself up and on a paddle board there isn’t anything We got over that by using the paddle to push down on the board
And though it doesn’t look exhausting it really is because you have to use your core muscles to keep your balance, a bit like a Pilates exercise ball
My tummy muscles were so sore the next day! But so worth it, I loved it
I’d have said riding on Dartmoor, but not really as the horse does most of it.
Dartmoor letter boxing was exhausting though, but great fun. Tramping for hours across the wildest parts of the moor searching for letter boxes, with clues to find the boxes, map, compass & food/drink with us in the height of Summer . One day we, the group, were out there & the 10 Tors was also going on & a helicopter must have thought we were part of it, so they flew low over us, realised we weren’t & sped off again. No GPS & other gadgets in those days, we did it ourselves, no mobile phones either, we had walkie talkies in case.
Once, on Bear Down, we searched high & low over an area we knew the letter box was, siting on the ground, our leader smirking at us, we were all looking everywhere. Then one clever member of the group twigged, ‘he’s sitting on it,’ He said. Yes, that’s exactly what he was doing, we really told him what we thought, he was laughing so hard he couldn’t get up, so we pulled him up & pushed him over so we could unearth it.
I’ve seen more of Dartmoor & the really wild parts, with that group than I ever would have if I’d not taken up letter boxing. I was also pretty fit in those days, with that & the horse riding.
Definitely sailing. Dart 18. It’s fun but requires concentration!
Yes, great fun. I was lucky a few years ago & spent a weekend sailing a Wherry on the Broads.
24hr cycling in torrential rain at times .
I think I have to agree with you about Dartmoor Letterboxing. Boy did we all get exhausted trekking all over, up and down tors, crossing streams.
I remember my daughter once, aged about 9, running across some boulders in the River Errme, to escape a herd of cows which were advancing angrily on us. It was so funny, she got to the middle of the river and had no idea how she’d managed it, then was too scared to make her way back so I had to go and help her back. We never did work out what the cows had against us, but we had to give them a very wide berth - they absolutely would not let us past them.
Exhausting, yes, but so exhilarating when we crested the top of a particularly high or difficult tor, and just sat, listening to the silence and gazing out over miles and miles of moorland. Pure bliss.
Great someone else did it too. Did you go with an organised group or on you own with friends etc? We did it with both at different times. Our leader was ‘The Letterboxer’.
It was just our family, Mr B and I and our 2 children. Sometimes if friends or family were visiting we’d take them out to find a few easy boxes, or one of our own.
We took out eldest grandson over to Pew Tor when he was about 6 and he absolutely loved it. That area is littered with them, so he found several.
I couldn’t manage it at all now. I really struggle with difficult terrain.
