How can you possibly do all necessary type of training (cardio, lactate, endurance) when your parental duties allow you to have only one quality session a week?
Necessity is the mother of all invention. My solution was a workout I called “progression run” that was recently described in RW as "boiling the frog". The idea is to gradually increase the pace to a level that otherwise would have been difficult (physically and mentally) to sustain right from the start.
That's how I "boil the frog", almost always on the treadmill: I run the first kilometer at 6:00 min/km pace. The next one at 5:30 followed by: 5:00, 4:30, 4:16, 4:06, 4:00, 3:55, 3:50, 3:45. Done. Two-minute break. Time to refuel and change a shirt. On a good day I can squeeze tree repeats. This workout is sort of 3-in-1 combo. With my target race pace of 4:10, the distance run at pace of around 4 min/km constitutes a tempo run, the sub-4 kilometers are mostly cardio, and the overall distance of 30km hopefully provides a benefit of a long run.
BTW. The photo was taken by Helen in the Museum of Nature here in Ottawa. The museum had a special exhibit featuring frogs. We just learned that some of them were the most poisonous creatures on the planet, even more venomous than snakes or spiders.
Lesson learned: be careful when "boiling the frog", it's easy to overdo it!
Run Strong,
RPB