I'm thinking of learning Brazilian Jujitsu but dont know how it will impact my running...anyone with experience?
Also should I forgoe the in class instruction of Brazilian jujitsu and just learn it by the book and by online videos?...because classes are too expensive for me right now.
I have been doing Judo for 10+ years, but took time off from it when I was competing xc/track in high school and college. Martial arts put an entirely different stress on your body, especially grappling ones. You will have bruises, your whole body will be sore, you will feel an entirely different aerobic stress, but it's worth it. You will definitely feel sore the next day on your run though. I currently am logging 50-60 mile weeks while training judo 3 days per week. I Plan on doing some road races soon so we'll see how I race. Depending on what your goals running are you probably will feel a bit more drained on runs. On the upside I feel and look more fit since I started doing both. As far as books and videos I'd say skip it unless you plan on using them along with classes. The atmosphere of a good dojo will put you in your place and you will learn proper technique.
I used to train martial arts in past, in my 20's. Now I'm 30's guy, and I just started running few years ago, after some years of doing literally nothing - just sitting in front of PC. What I can say? Karate lessons gave me huge impact on sprint speed, maybe 29 seconds 200m sounds like joke here, but I was always slowest guy in school, really doubt I could break 37 when I was 18. With my lifestyle and long distance training I should be somewhere near 40' for 200m. So yes, martial arts help alot, especially ones where you kick.
And no, you can't learn anything from online videos. If you can't afford lessons, just buy puncing bag - or even make one yourself.