Such a fun day for the first group training session. Weather was cool, sun was out. The key focus early in training is to strengthen connective tissue, build muscle, and do some aerobic conditioning.
The aerobic system can be developed fundamentally by time on your feet. This can be done very effectively at 60% of HR Max. To maintain & develop your aerobic engine, the bulk of your training plan should be relatively easy in effort. In addition, at easy levels of effort, the strain on your connectivity tissue is reduced and recovery is substantially easier, which reduces overall injury risk.
Squats, lunges, planks & bridges introduce load to the musculature and connective tissue. Over a course of 4-6 weeks, consistent body weight strength work will make you a stronger and injury resistant athlete.
Combine 4 short, 10-min runs with multiple sets of strength work and now you have a formidable, time-efficient workout that works everything you need to begin to set your running base and improve your durability as an athlete.
Be efficient with your time, stay out of the gym at least for now, and enjoy the fall weather. Bask in the glory of being outside during the changing seasons with your friends.