Exercise technique

Something I have been doing that has improved my endurance during my training is so simple that I'm wondering if it's actually helping or merely a placebo effect. Calf raises! I don't do them with weights but I do it on an uneven platform. I take the cushions off my couch and stand on it so its very shaky so I have to work on my balance as well as doing the exercise and I swear so far it has helped greatly. Anyone else tried doing exercises like this but not in a routine way?

 

I think any kind of exercise, not necessarily using weights, can increase the stamina. It is a matter of your body getting used to the rigors of exercise whether it is a simple bending and stretching or the sit-ups and the push-ups. For me, what's important is the duration of the exercise. My friend who is a gym manager told me that there are many ways of strengthening the legs and one simple way is to use the stairs.. up and down, up and down until you trip due to fatigue (the trip is a jest).