Reading a few threads in here...man there some guys my age who are bad asses. Most have trained for far longer than me and got strong before they got older, but....wow.
Anyway, with my schedule, I work every other Friday. And since I use our corporate gym for just about everything, I use those Fridays (of late) to get some Concept 2 rower sprints in. Wednesday I did 100m sprints followed by 90sec rests for 9 intervals. I decided that wasn't enough time to get the heart rate to peak, so I upped the sprints to 125m, same 90sec rest. Kicked the crap out of me. I've read some guys hitting 1:15/500m splits doing that. I'm still a beginner, but that's a long way off for me. Doing 100m sprints, I was able to get to 1:25/500m splits, but that speed was not possible for me to do when the sprints went up to 125m. It was closer to 1:33/500m. I'm going to stay at that level and work on improving times.
So....for today's result:
5:00 warmup
9 x 125m sprint with 90 second rest between each.
3:00 cool down
Stagger back to the locker room.
By the way, most of the folks in the gym doing their 2.5 mph treadmill cardio turn around with dazed looks at the Old Dude who every couple of minutes starts raising a ruckus for a short time. I'm guessing they have less than zero idea why anyone would do it this way.