Should runners hit the weight room? Absolutely!
The amount of time, the type of exercises, and the number of repetitions spent utilizing weights all depends on the individual and their goals. Most runners that choose not to lift weights worry about building size that will decrease mobility and cause greater effort. With a proper training program designed for runners there’s no need to worry.
There are all sorts of health benefits to resistance training, but we’ll focus strictly on using weights to improve running performance and reduce the likelihood of injury.
The easiest way to describe the methods of resistance (weight) training is to break them down in to 3 separate categories. They are strength, hypertrophy, and endurance. While modern weight lifting is a blend of all three, you’ll find athletes will mostly lean toward the style of resistance training that fits their goals and lifestyle. As an example; a power lifter will focus on strength training, a bodybuilder will almost always train for hypertrophy (muscle growth), and a runner for endurance. These three methods are identified by their “rep ranges” and rest cycles.
In order to maximize the benefits of resistance training for an endurance athlete, we’ll train in a higher repetition range that improves muscular endurance without building muscle mass or strength. These are high rep sets, typically above 15 repetitions each or a sequence of exercises with little or no rest between movements (circuit training). This means choosing a weight that is light enough to perform the prescribed number of repetitions to reach the endurance training zone. Just about all endurance runners can benefit from this type of resistance training without worrying about decreasing mobility or running efficiency. Actually quite the opposite is true! A proper endurance training program will help raise your V02 MAX while giving your lower body endurance to sprint off the start, finish strong, or push through those hills.
If training strictly to improve your running performance then stick to two full body resistance workouts per week. Focus on major muscle groups, performing 2-3 sets per exercise and about 15-25 repetitions each.