This is true. But once you've gotten in the groove of exercising, then a 10 minute jog/run to the gym from cold should not be a problem if there's no underlying problems.
If all your doing at the gym is weights, then that jog/run is most of the warmup you'll need. Just throw up some stretching to deal with any kinks and a warmup set and you're good.
If all your doing at the gym is weights, then that jog/run is most of the warmup you'll need. Just throw up some stretching to deal with any kinks and a warmup set and you're good.