Recently, the Hideout and Crafting skills were added. The Hideout skill in particular is what I am gonna be talking about. Right away I understood what it meant. When that skill was implemented I was around 620 raids total, level 8 strength and level 22 endurance. I decided right there and then to keep an FP-100 filter in permanently. It took me roughly 180 or so raids to reach my goal.
The way the multiplier works is fairly simple. You get 1% per level of hideout skill of your total increased physical skill boost. So at max you're getting an additional 20% for a total of 60% boost. I only got to level 22 hideout before I maxed strength and endurance.
My strategy: Keep a FP-100 filter in always, bring an insured Tank battery in your back pack. Sprint out your full stamina bar upon spawn. Dump your battery in a bush or somewhere that you think is safe to get returned in insurance. Play your raid out as you see fit. 7-8 minutes later your Diminishing returns will reset on strength and you can get another chunk of points.
My average was 14 points per stamina bar. Sometimes more, sometimes only 8. The most I got for 1 bar was 31 points. What decides this I have no clue. By using this method you can expect to get a minimum of 20 points per raid but up to 70 and beyond if done correctly.
Notes: I noticed that the red % icon that shows the diminishing returns were not resetting correctly. So after some tests I just decided to go off my phones stop watch on exactly when 8 minutes had passed.