I mean for those 60? in the long Z1, should I consider 10-15 minutes of warm up and 5 minutes of cool down?
I’d say for Z1 sessions, yes since it’s mostly volume centric and recovery. But for Z2 sessions, I’d do my best to keep the 60′ in Z2 with the warm up/cool down in addition to the 60′ (so…75-80min total for Z2 sessions).
it is better to do more workouts with less time rather than few workouts with more time
Your workout lengths need to be long enough to illicit a training effect. If they are too short you won’t be demanding enough of your body to challenge/train it. An extreme example would be imagine doing 180 workouts, each workout being 1 min long (180 minutes cumulative = 3 hours). Probably not too effective.
If you’re just starting out using a formal training program, follow a similar model as what Scott has in his post (short-medium length workout sessions, dispersed across the week with rest days incorporated within the week). This will give your body a more gradual transition (aerobically and physically).
Pay attention to how you feel and adjust accordingly.
If you’re familiar with training programs and have some aerobic/physical base, you can have 1 “longer” aerobic session in the week (~1-2hr).
Over time it will come down to a matter of how much time a person can dedicate to training (i.e. volume). If we have a large objective/goal that requires a lot of training time/volume…the only real solution is to spend more time training or change your objective/goal to something that can be achieved based on the amount of time you can dedicate to training.