woohoo another useless study that doesn't put markers on their results.
Know how long it takes? Well, if your balls are hot, then you are losing sperm. It takes a minimum of an hour and when your lap starts to get really hot, then take the comp. off your balls and you still have swimmers.
This reminds me of the whole saccharin (nutra-sweet). Remember it can cause cancer in lab mice!!! Only they fail to mention that the equatable amount to us eating it to obtain cancer is well over 50lbs. You will never eat that much fake sugar in your life. If you do, then cancer is not your worry, morbid obesity and heart failure are.
Most people don't put the laptop directly on their balls anyway. I know I put mine on my knees most of the time. Occasionally it sits on my balls, but not more than 5min because I don't like the weight on them
Don't worry about "studies." I actually am working on 2 clinical studies, and you can make them say whatever you want based on parameters and leaving small bits out.