Water weight after strength training?

Yes.
Go ahead and walk. Don't lift weights today. Do it tomorrow.
look up 'foam rolling'

Its from the build up of lactic acid in your muscles - using a foam roller after your workouts and even spending time in the sauna if your gym offers one. Follow up with protein shortly after your workouts to help heal muscles - I usually follow workouts with a protein shake that includes l-gluatmine. You should take a day of rest from weight training between sessions.

I heard that after working out, your muscles get all pissed off and retain water.

lol i love that. true. you will retain water weight. get used to the lovely cycle of that, with an extra layer of annoyance added when you get your period.

yes.. you are not eating enough. and i second the recovery protein post workout. i use ARM ( a max muscle product) it works great and taste failry decent -strawberry and watermelon. it does help with feel less sore... but to be honest if you just strated this new workout rotuine.. you will be sore. and somethign to keep in mind is dont stop moving.. it only makes the pain worse. on your 'off' days take a walk.. swimm...dance.. something. I've noticed that the pain only gets worse if i sit the entire next day.

This explains so much. I would lift weights then suddenly feel like I am doing something wrong even though everything seemed right. Good to know.

I have been training for years and I always a bit sore the day after. Eventually, the soreness gets less and less. Lifting weights for 2 days would not account for 4lbs of weight gain. That could be water weight. It also depends on what time of the day you weighed yourself the first time and the second time. Try to do this at a consistant time of day and in cloths with similar weight. You would be surprised what a difference a morning weight and a late day weight can be.

You can, and should walk. Your muscles build up lactic acid and light paced excersise like walking burns off that acid which helps burn fat and build muscle. Just don't over do it. Eat low fat foods with high amounts of protein and low amounts of sugar. Stay away from processed sugars.

At your weight, don't expect to see a lot of weight lose very quicly. Those ads that say loose 10lbs in 2 weeks are for people who weigh over 200lbs. Unless you are 2'7" tall, you are most likely in the average range for body fat and weight. Stick with it. You will get there.

Lastly, take measurements besides weight. Measure your waist, hips, chest, neckt, upper thighs, upper arms. Muscle weighs more then fat, it is more dense. You can add weight and loose inches in certain areas where fat gets stored. I once weighed 220 and had a 40in waist. I lost 50 lbs and had a 34 in waiste. After weightlifting for a number of years and eating differently I weigh 185 and have a 33 in waist.

Good Luck

Could I use a rolled up yoga mat?

I'm having the same issue. Just started strength training this weekend, so far have got in 4 days (split body) and I'm up 2.2 lbs? I weigh in the morning too, after peeing. Cardio didn't do this to me, so I am hoping against hope that it's water weight. Weigh in is on Friday for me, and I really, really, really don't want to be up, especially since I'm doing everything right.

How long does this extra water bloat last? Is it something that just happens at the beginning of weight training and every time weights are increased? Or is it just permanent until I stop weight training for a few days? Not that I will, since I am tired of being weak. Just want to know if this is my 'new' set point to go off of.

about 8 days after lifting I am up 6 pounds-WTH?

I don't have a foam roller.......would a rolling pin work? hahaha

Check your gym, they may have some in the stretching area. Foam roller, not a rolling pin.

The only reason I would say a rolling pin wouldn't work is because it would just roll with your body. You want some firm that you can use your body weight on the item to apply pressure to the pressure point, a baseball works just as well.