U.S. hospitals treated almost 1 million training-related injuries between 1990 and 2007, according to findings from an 18-year study published three years ago in The American Journal of Sports Medicine. What’s more, most of these people were injured while doing exercises with free weights.

Beth Shephard, MS, a certified wellness coach and an American Council on Exercise expert, notes that unless you’ve been properly trained, it’s easy to get weight training form and technique wrong.

To reduce your chances of getting injured and making mistakes, always warm up first. Get the blood flowing with some light calisthenics, such as jumping jacks or running in place. When you start strength training, use light to moderate weights. Once these become easy to lift, increase the weight or raise the number of repetitions you perform.

Finally, once in a while be sure to mix up your routine with new exercises.