After several months away from sim racing, I found myself much slower than used to be in LFS and I practise quite a lot these days to regain speed.

The problem is, very long hours of practising makes me feel dizzy. In less than an hour my eyesight gets blurry. If I try to take a break on the long straight line it'll be difficult to re-focus on the screen. After two or three hours of continues practising, I can hardly recognize what I'm doing at the moment, and driving gradually becomes a kind of "unconscious" reaction. What happened at the last chicane ? I can't remember.

The fastest laps usually occur during the first hour. After that I do feel I continue to learn more about the track but the reality is I gradually become slower and slower. Finally, I'll have to slow down significantly on purpose to avoid a crash because concentration gets lost easily.

I'm wondering if those relatively slow laps really help. Do those tiring laps improve my skills in some way, or I'm only spending my time doing something pointless ?

ur spending ur time pointless imo

1hour races or practice improves you more. after that take a brake or smth

thats right.
do it in little steps.
will help much more than playing long time at once.

I do have the same problem, but I found out that it always happens when my focus switch from perfect trajectories to lap time...greediness is what makes us push more than necessary and we end up over driving the car and ourselves. So the key for me is to forget about splits and lap time and get back to drawing trajectories the best I can.

But of course we are all different, so I agree with DMT's comment, in general it is better to train inside our concentration's limits.

The main thing in trying to learn how to drive fast is finding just how fast you can drive into a corner and how early can you accelerate. If you lose focus and do not try to find the best lines and instead just drive safely and slowly you aren't getting faster. In order to learn the driving lines right you have to drive in the limit. When learning the speed it's not really about how much you drive, it's about how hard you try to find the lines. Driving 2 hours slow is worse than driving 1/2 hours driving in the limit

When learning a new track or trying to remember an old one I usually first check lfsworld and the basic lines, gears etc. Then start driving a few laps easy just to remember each corner. Once you can remember each corner you start pushing. Go harder and harder into the corner. If at first you go just a bit wide most of the time it means you're on the right track. If you're not driving out or crashing once in every 5 laps you're way off in your driving style.

And remember the main thing in learning how to drive fast is comparing your time in lfsworld with the best. In lfsworld you see where you lose time.

I've just had 3 days of extreme training to make up ground on guys that started training a lot earlier. That means I was driving around 4 hours a day all in one pace rather than braking it up in four parts an hour. Of course I took brakes here and there 5 or 10 minutes long just to catch my breath and those short brakes really help you a lot.

One thing that happens to me with long practice is that I get too eager to push more and more all the time as I've just learned something the last lap, it's never enough, so I end up almost always failing to complete the lap to set new PB, get frustrated and decide I'll go and do the PB even if I have to forget everything I just learned and new PB comes, but still a mistake has to be somewhere in process and in process I discover new things again.

My tip would be just push forward for as long as your body is not in real pain

maybe you should get reading glasses

For me those "symptoms" sound similar to what I experience when I haven't had good night sleep or there is some other reason for being tired.

If I haven't got enough sleep the night before it's hard to concentrate and driving becomes somewhat sleep like. I may be able to drive somewhat competitively for an hour but the performance isn't good as it should and I tend to easily make mistakes. But when I'm not tired and I'm in the right driving mood I can keep racing for pretty much endless amount of hours without any problems. I may start to feel a bit tired at some point but it's different and doesn't make me loose my concentration.

Are you sure you just simply are sleeping enough at nights? Driving sims usually require huge amounts of concentration and at least for me I really need the good amount of sleep per night to be able to concentrate properly.

You race as you practice...

So, you really better practice on the edge/limit.
Otherwise, you're just conditioning yourself to race as fast or as slow as you practice.

There's really no way around it.

Don't sacrifice your real life and health to become better at a video game.

Quote from degraaff :

Don't sacrifice your real life and health to become better at a video game.

True, true but is advisable to have a hobby man