Stairmaster intervals provide possibly the most efficient and intense cardio exercise. Your heart rate jumps up to max immediately.
You can do 30 seconds of high-speed anaerobic intervals then slow down for 60 seconds, and repeat at the speeds that work for you. If you can do two steps at a time on the higher speeds, so much the better. Another approach which I am using now is to do 3-minute stairs at the highest speed I can handle for that long, then get off and do a one-minute plank and another minute to breathe, then back on. Thus a 20-min cardio work-out which also beats the hell out of your quads.
What is it good for? It's for intense cardio training, lower body endurance, core stress. It doesn't build strength per se the way squats and deadlifts do, but it does work for lower body "toning" at the least.
Because it is very low-impact, about the same as walking, it is also a cardio recommendation for people with bad knees, hips, and lower back.
(Readers know that we believe that two 20-30 minute cardio stress sessions weekly is enough cardio, if combined with the other weight and calisthenics routines.)
Five hours or less per week of weights, calis, and cardio is all it takes for general Fitness for Life. Then throw in some sports or hiking or yoga or golf or swims or whatever for fun, plus some Cokes or beers as rewards, and you've been a darn good steward of your body, which is your most important real estate. Anybody can find time for that. Just avoid any distance running or you will regret it.
