how many inches of fat should i be able to pinch?

0 inches.

Jumping jacks don't do anything. Situps are good if you are doing them right.

If you want to lose weight and gain muscle:

- Run 30 minutes + each day

- Lift weights, dumbells or whatever is around your house

- EAT LESS.

You are 13 and at that age we all grew rapidly. There were times when my son seemed to be a little too chubby, and then suddenly he shot up and slimmed down. As far as the pinch test goes doe I know that in the military you could not pass if they were able to get more than 1/4 of an inch...I don't know if they still got that kind of thing going, that's how it was....

Sit ups will flatten your belly and jumping jacks are a pretty good cardiovascular exercise. However, if you really want to lose some weight without a diet, add running to it---running tracks burns a LOT of calories.....

uhhh what?!

well i dont understand completely..

but when u sit down and curve over u shoudl get about 3 inches of fat might seem like alot but its normal.

caus ei dontt wanna be to skinny/fat

ur age doesnt matter you can buy this thing that piches you and tell you how much fat you have on ur body.. and you have to be standing..