- *When doing weights you should do 2 or 3 times 8 or 12 repetitions. If you cannot get to 8 repetitions you are lifting too much. By the last one or two repetitions it should be getting *really* hard
*When doing muscle toneing exercise like swiss ball, stomach crunches etc. most people can do three more repetitions after they get to the 'oh my god I *must* stop' stage. You get heaps of benefit out of pushing through those extra 3.
*On cardio machines using the random and hill settings burns more kilojoules than staying at the same resistance.