Many fitness programs assume 60-90 minute sessions. Effective workouts can be 30-45 minutes for most general fitness goals. Longer sessions often produce diminishing returns or actually worse adaptation due to extended cortisol elevation.
What 30-45 minutes accomplishes
Full compound lift program (3-4 lifts, 4-5 sets each). HIIT cardio session. Substantial yoga or mobility session. Adequate stimulus for most adaptation.
If time is the barrier to consistency, drop to 30-45 minute sessions. Better to train 4x weekly for 35 minutes than once weekly for 2 hours.