One of the best ways to do a dynamic warm-up is to do the same exercise you are planning to do but at a slower pace. Suppose you are taking a spin class. To warm up, cycle slowly on your bike for 5 to 10 minutes. Once you are warmed up, you can increase your speed. If you are strength training, you’ll still want to warm up with some mild aerobic activity. You could march in place for 5 to 10 minutes. Swing your arms back and forth to warm up your arm muscles as well. If you have any health issues or haven’t been active in a while, make sure to talk with your doctor before starting any new exercise routine.