Should you lack the funds to attend a martial arts class (some local clubs are relatively inexpensive), you should still attempt to train on your own. You can do this through rounds of shadowboxing, above and beyond the Real Anime Training workouts, or you can practice any techniques or kata you have learned from martial arts classes you've attended. Plus, there's sparring, which is always a good choice.
Personally, I use shadowboxing as a way to train my martial arts skills when I can't attend class. I use 5 x 5 Minute Rounds and it works great for me, but you pursue whichever path you like.
I should have an Hajime no Ippo post up for you later tonight and maybe another workout. Till then, good luck and train hard!