Josh T, one of our followers from Australia, seems to delight in recommending some pretty tough workouts for us to do. Here's the most recent one:
Lift a combined total of 30,000 kg using Pull Ups (your weight), Sandbag Back Squats and Sandbag High Pulls. Any weight allowed in the sandbag and you can break up the sets and exercises however you wish. But, you must lift a total of 10,000 kg for each exercise.
Something like this would be good:
5 Pull Ups,
10 50kg Sandbag Back Squats,
10 50kg Sandbag High Pulls.
Repeat for 20 rounds (or so).
Record your time.