Try and work them 3 times a week, every other day is ideal cause your muscles need 48 hours to recover properly.
Its hard to say, its not an exact science, there a lot of things that contribute, also it just depends on what state there in at the minute I guess, but do sets of 15-20 reps/crunches if you can manage, make sure you breath out as you crunch and in as you lower back down, SLOWLY, do as many sets as you can, 3 min, 5 is great.
It takes a while to see a big difference, but you should feel firmer afer a couple of weeks, if you keep it up for 5, with a good diet and other exercise, you should notice a fair difference, and feel a lot better as well.
Same with dumbells, every other day, depending on how heavey they are, try and do at least 3 sets of 15 reps, for your shoulders and arms.
Good luck!
Its hard to say, its not an exact science, there a lot of things that contribute, also it just depends on what state there in at the minute I guess, but do sets of 15-20 reps/crunches if you can manage, make sure you breath out as you crunch and in as you lower back down, SLOWLY, do as many sets as you can, 3 min, 5 is great.
It takes a while to see a big difference, but you should feel firmer afer a couple of weeks, if you keep it up for 5, with a good diet and other exercise, you should notice a fair difference, and feel a lot better as well.
Same with dumbells, every other day, depending on how heavey they are, try and do at least 3 sets of 15 reps, for your shoulders and arms.
Good luck!