If given a choice between spending more time outdoors and doing pushups or planks, I would invariably choose running outdoors. As I start to increase mileage, pain in my back serves as a reminder that the state of my core does not match the distance I run. You could say strength training is obviously important. Yet I fail to appreciate this until I experience the negative effects of not doing it. I guess this is another example of why doing the things you do not like is important: this is how you grow. Doing pushups is so easy to overlook: no special place or equipment is required. You can do this anywhere and any time of day. How good it feels to stand up from the desk and do some pushups for a change. It gives you a different angle at whatever problem you are trying to solve at that moment.