Opportunistic Training (OT) is the training type that is closest to your typical “gym workout time” and refers to those occasions where you do have time to train for more than 10 mins in an uninterrupted block of time. What you don’t have, and what distinguishes OT from normal structured training, is the possibility to plan exactly when and where you’re going to train.
OT is a form of dedicated training time in the sense that you know you can dedicate your attention to training, mostly uninterrupted, for the next 15 mins at least. This means you can plan your session with some structure in it: some warm-up, then exercises combinations you actually design for maximum training efficiency.
OT doesn’t have to be totally, 100% time that you dedicate to training, so long as you can plan your session with the benefit of knowing you can most probably use the next 15 mins to train.
For me, I get OT sessions when I go to the playground with my 3 kids, or when I go pick up my daughter at school. But it always depends on the situation. Some days all 3 kids in the playground play by themselves happily, and I get to do some moves; other days, I have to be really hands-on and while I can get some training done, it’s Interstices Training more than Opportunistic Training.
Same at school pick-up: if my daughter wants to play outside with her friends and we have time, then I can take 15 mins to train while keeping an eye on her. But if she’s feeling tired after school or something in her day went wrong and she wants to talk, then it’s my priority. I only find out when I pick her up though.