I used both methods with my cross country team and had good results. Beginning runners shaved about 2 min. off their 2 mile time and advanced runners showed steady improvement. Some days we'd go straight sprints/mid distance with rest and on other days we'd go 400m/push up, sit up, squat, lunge, 400m, repeat.
These methods mixed in with an LSD day once a week prepped our runners for meets. I was also asked to train our 7th grade soccer team due to their lack of fitness to go 30 minutes per half without rest. The first time the soccer kids trained with us was the last time they tried. My slowest (and I mean SLOWEST) runner beat most of the soccer team in a training session that included 800m runs with 4 bodyweight exercises in between runs.
As a side note, combining running with bodyweight exercises allows the athlete to use the exercises as active rest and builds some mental toughness. The athlete actually looks forward to squats and lunges during the run.
Hope I answered the question.