Yeah, but that’s not what the OP asked. He talked about maintaining strength while not training at all for 6 months or so.
Strength is mostly a factor of muscle size and nervous system efficiency. If you lose either one of those you will lose strength. If you lose both, you obviously lose strength faster.
If you take an extended layoff away from all training (strength or hypertrophy) you will lose muscle. You can do things to slow down muscle loss like doing sprints, hill sprints, pull-ups, push-ups, handstand push-ups but if you have been lifting seriously, you will still lose muscle during a layoff. Now, the speed at which you are losing your muscle is not correlated with the speed at which you built it. But rather by HOW LONG you’ve had the added muscle mass. Someone who has been muscular for 20 years will maintain more muscle than someone who has been muscular for 5 years.
So except for training experience, there is little you can do training-wise to have a slower muscle loss pace.
Neurological adaptations are somewhat similar. The longer your nervous system has been efficient, the less likely you are to lose that efficiency. You will still lose some if you stop training for an extended period of time but if you have been neurally efficient for a long time, you will maintain a greater percentage of it.
A friend of mine was a former national champion in weightlifting. His best clean & jerk was 192.5kg. He was still doing a 180kg clean at 38 years of age. At which point he stopped training for 7 years. The first time he got back to lifting he cleaned 165kg. The guy had been lifting non-stop since he was 12… he had 26 years of hard training behind his belt when he took a break. He also always trained as an olympic lifter, doing mostly neurological work. After 26 years of this his nervous system adaptations when really solid. So he maintained a lot of strength. In fact after a month of training, at 45, after not training for 7 years, he squatted 500 x 5.
So the same rule applies for strength (even more so in fact) as it does for muscle: the longer you’ve had the strength, the longer you will keep it and the faster it will come back.
As for which type of training facilitates a slower strength loss when you stop training for a while, that’s hard to say. I would say that those who used a higher frequency (hitting the main lift several times per week) using a strength-sill approach might maintain strength better. But an argument could also be made for having a lot of muscle mass helping slow down the losing process.
But besides experience and having been strong/muscular for a long time, nothing will really prevent the strength loss.
That having been said, you don’t need much to maintain your strength. Doing one workout a week where you do the squat, bench, deadlift for something like 3 x 3 @ 87-92% should allow you to maintain your strength while you are taking a break.