Increasing stamina....
Push yourself when running, cycling, swimming and try to break that barrier, Its like stretching your legs, you keep stretching to your limit then apply slight pressure beyond the limit. Each time it gets looser.
Abs...
I like working with a yoga exercise for the abs where you lay on your front, put your hands together under your chin with your elbows point out at 45deg. spread your legs shoudle width apart and then lift your wieght and hold it so your balacing on ur forearms and toes.
Hold for maybe 1 minute then lift one leg and hold, place leg down then lift other leg and hold, place back down and do the same for each arm.
After that cycle raise 1 leg and 1 arm e.g left leg and right arm and hold. then repeat with the others.
Try to breathe evenly and relax as much as you can. Determine the time by feeling how tired your muscles are getting.
