https://cdn.discordapp.com/attachments/210531123183222784/546746377837740032/unknown.png
This image breaks down how effective leveling facilities are so you can figure out the % gain per day. It's doesn't work on a % increase system rather you get more energy points to spend in a day instead.
.)Training efficiency correlates with your players Energy. Between 75-90% seems to be the sweet spot.
.)Energy has a higher impact on your training efficiency than 1 Lvl of gaming Gear (prop even 2-3 lvls but didnt test that)
.)There seems to be a random espect on training efficiency since a player got diffrent stats on 2 days while having same training schedule and energy.
if you found out something I would be happy to hear it :)