In the off season I do three sessions a week but generally keep them quite short and mix it up.
So, for eg this morning was 5 mins pull ups, 5 mins press ups and 5 mins squats with 1 min recovery and includes a run to and from the park (where the equipment is) as warm up and cool down. Whole session 30 mins
Mon will be 3 x 6 clean and jerk using the Olympic bar followed by lunges and squats. Whole thing will take around 15 mins.
A third session might be a 30 min kettlebell session.