I recently got a question from a new student about judo specific strength and conditioning, and I thought I would share my reply. I am not an expert on the question, but I know what works for me, and I can point you in the right direction for further study.
The best thing to do is get an appointment with Jeff Bott, the owner of Oakland Strength Factory and a top-level physical trainer. He can make a comprehensive evaluation of where you are now, and help you reach your goals. Jeff is one of my training partners and a brown belt in jiujitsu himself, so he understands grappling strength. Sensei Ivan, Jon, and a few other of our judokas have been training with him recently, and they all report much improved mobility, strength, and body mechanics. You can reach him at email@example.com or 510-227-8069. I trained with Jeff myself for a period last year and it definitely helped!
Currently I am using only body weight exercises such as push-ups, sit-ups, pull-ups, dips, etc. You can start with something manageable like 20-30 push-ups and sit-ups per day and then increase from there.
For cardio, I like to do sprints rather than long runs. Again, this is just me – distance runs of 3-5 miles 2-3x per week may be very beneficial, but I find sprints help me in a shorter amount of time. Lake Merritt or your local high school or college are great places to run, but anywhere without much traffic will do. Thorough warm-up with a 10-20 minute jog followed by stretching of the hamstrings, groin, hips and low back is important before you dive right into sprinting, otherwise you can give yourself an injury.
Once you are warm and loose, pick a goal like the next lamp post or wherever, and then just see how fast you can get there. From there it’s simply a matter of slowly increasing your reps. You can also vary the distance of your sprints, although sprints longer than 400 meters may not be as helpful – then you’re getting into a distance run where you have to moderate your pace.
I should mention that some good quality running shoes are very important!
There are also some public stairways around Oakland that you can use for sprints. Next to Lake Merritt off Lakeshore there is a set of stairs many people use for conditioning, but you may find them in many places in the hills, and of course at college or high school stadiums. Set yourself a goal of two or three sprints up the stairs and take your break as you come back down the stairs. On the way up, go as fast as you can! For variety you can try hitting every step, or skipping one or two steps, or even jumps with both feet at the same time. Again, warm up is crucial and good shoes are a must.
You can also try some online programs such as this one by Matt D’Aquino, an Australian judoka and former Olympian. I haven’t tried his system myself, but I have watched many of his videos and he seems to know what he’s doing.
Once you pick a program, whether it’s with Jeff, or one of your own design, stick with it and try to do it at least twice a week so you can see the results.