Among other changes, recent Training update added an important detail: unlike before, no injuries can happen in the training now.

We've also increased the % of recovery every 3h to 6%, that means players gain 8% more condition every day than before (1% every 3h more). In fact, they recover 48% condition every day.

And about rests, the need for rests is not that high, and if you see yourself struggling for that, maybe you need to do some changes in your daily activities / training.

In my personal case, I like to train after all daily matches have already been played, on late evening, before going to sleep. I know everyone will gain 18%-24% condition the next time I open the game, in the morning, and because no injuries can happen, I train as much as I want, to reach 10% on each bonus (defensive, offensive, condition and possession. I know they will be reduced by 2% by next day, but then I will be 8% on each and really close to be max again.

The only thing I consider is the upcoming match. If I have a match at 13h next day, I want to be sure they will be fully rested more than 3h before that match, so I can do a quick training in the morning (with 6% condition recover) that will reach me to all 10% bonus again. As this is usually not enough, what I do is overtrain all players I have who never/rarely play, substitutes and others, so I can effectively reach this 10% (sometimes is not possible, but in these cases I get 8%'s and 10%'s mixed).

So I end up with a fully recovered team with (almost) all training bonuses at 10% (maybe not, but having full 8% it's also very good). Then if you have 3 matches on a specific day, your players will actually be recovering faster than before -I already explained why- so the situation will be better than it was before the new training came up.

I may have used the option to give +6% to all team for 8-9 rests a couple of times in the whole season. I've only been recently knocked out from Cup, so it's a good example. In fact, I have more rests than I was able to accumulate before.

Of course if you are trying to reach from 0% to 10% bonus in the morning BEFORE all your matches happen, you will end up needing a lot of extra rests. Don't do that, be smart and train after that, take advantage of the long periods that you won't connect at all (for many reasons, mainly because you need to sleep, work, etc).

That's the way I do it, works for me. Maybe it won't work as good on other teams, but give it a try