The lung is a pretty simple movement that you've certainly carried out countless times before, but there are a few significant subtleties that you can consider in order to shield yourself from knee injuries further down the track.
1 mile Run 75 Air Squats 75 Russian Twists 74 Medicine Ball Lunges (20/14 lb) 800 meter run 50 Air Squats 50 Russian Twists 50 Medicine Ball Lunges (20/14 lb) 400 meter Run 25 Air Squats 25 Russian Twists 25 Medicine Ball Lunges (20/14 lb)
Then, 2 Rounds of: 10 Burpees 25 meter Bear Crawl 25 meter Crab Walk