very sore legs after my first race

Quoted message said:

The day after the (10 km) race I could hardly walk, and now my
quads and hamstrings still hurt. Is this normal ? Do people who
are correctly trained for the race also get such sore legs ?

No.

Quoted message said:

And do you have any tips to prevent this, if I decide to enter
another race ?

Train for the race, or jog it slow enough that you don't get sore.

Quoted message said:

I ran my first race (a 10K) last sunday. I didn't really train for
this, I just run once a week, but some friends talked me into entering
the race, and so I gave it a try. It was much fun, but it gave me very
sore legs ! The day after the race I could hardly walk, and now my
quads and hamstrings still hurt. Is this normal ?

This is expected if you only run once a week. Especially if you have
never run that distance or that pace or that combination of distance
and pace. Unusual trauma to the leg muscles will cause DOMS (delayed
onset muscle soreness).

Quoted message said:

Do people who are correctly trained for the race also get such sore legs ?

As Charlie said, no. However, despite proper training you may feel it
to a lesser degree, or maybe just dead legs. It certainly won't be
painful or to the point where you can hardly walk. Probably nowhere
near that bad. In training for a 10K most runners don't actually run a
10K at 10K race pace, but you do over-distance running (longer than 10K
at slower than race pace), and speed training (shorter intervals, but
at race pace or faster). So even someone that is properly trained may
feel some soreness because racing a 10K is a little bit different from
training for one. Of course you'd have to very gradually work up to
this sort of training program, especially if you're currently running
once a week.

Quoted message said:

And do you have any tips to prevent this, if I decide to enter another race ?
thank you for your advices.

There are lots of training programs out there. You should look for
something that fits the beginner category. Also, some more background
on you might be helpful. So far, all we know is that you run once a
week. Do you exercise in any other way? Any medical problems? What is
your age? Do you have any running history? Weight problems? Proper
running shoes?

--
Phil M.

I did something like this and ended up crippled for a year. Im just
getting back into running. im 42 so that is part of the problem. id be
very cautious. if it hurts, stop.

Quoted message said:

I did something like this and ended up crippled for a year. Im just
getting back into running. im 42 so that is part of the problem. id be
very cautious. if it hurts, stop.

At your age, you should be dead.