Haven't used it in a few years, but I had an indoor sprint workout you might find interesting. I would pull up videos of sumo tournaments, which might have 13-14 matches per day. After a good warmup, I'd start the video and every time a match started, I'd do a max sprint for as long as the match lasted, then recover between matches. The matches might run from as short as 2-3 seconds, to sometimes well over a minute. Didn't matter, I would start at full sprint and hold max power for as long as the match lasted.
Another indoor workout I did for VO2 would be to watch a pro level boxing match and do VO2 efforts during the rounds, and recover in between. Didn't need to faff around with worrying about the timing of the intervals, no fiddling with the lap button, just hit the power when the bell rang, and shut it down at the end of the round. Lather, rinse, repeat.
Another indoor workout I did for VO2 would be to watch a pro level boxing match and do VO2 efforts during the rounds, and recover in between. Didn't need to faff around with worrying about the timing of the intervals, no fiddling with the lap button, just hit the power when the bell rang, and shut it down at the end of the round. Lather, rinse, repeat.