As runners we can get a little too focused on, well, running. We know cross-training is important, but many forget strength training. Some even worry lifting weights will bulk them up, which simply doesn’t happen unless you’re taking extreme measures.

To get the most out of a strength training routine, aim for two workouts a week for at least 30 minutes. But even a half hour once a week is better than nothing.

To run your best, improve your race day performance and avoid injury you need to build up more than just the muscles you use to get your legs moving.

Here’s why runners need to add strength training:

Your glutes and core are key: These two muscle groups are the powerhouses of your runs, but – guess what – you don’t work them hard enough during your runs to improve them. Back and hip exercises are also important when you’re pounding the pavement day after day. Workouts focusing on these often-overlooked areas are sure to help you come race day.

You’ll reduce risk of injury: Strengthening the muscles that support your running legs can greatly reduce the risk of injury. In fact, if you do get injured and go to physical therapy, you’d be amazed at how many of the exercises they take you through are strengthening ones – there’s a reason for that. Stronger joints and muscles mean your body is more prepared for the pounding you take every time you hit the trail.

You’ll look and feel better: The old saying that muscle weighs less than fat is not correct. Put a pound of muscle on the scale next to a pound of fat, and they will both weigh … well, one pound. What is true is that muscle takes up less space than fat. That means reducing fat and building muscle will give you a leaner appearance and shrink your body measurements without necessarily a drop (and sometimes an increase, actually) on the scale. In addition, increasing your muscle mass will increase your metabolism.

You should still strengthen your legs: I know we kicked off this article saying you need to build up more than just your leg muscles, but you shouldn’t completely ignore them during a strength training session. Squats, deadlifts, lunges – these and other leg-based exercises are key to getting stronger and faster legs.

Don’t forget your upper body: No, you don’t run on your hands, but you also don’t run with your arms static at your side – that would just look silly. In fact, your swinging arms help drive you forward as you run and can help you out on tough hills or race courses, so strengthening them aids in your running form.

Combination exercises are great builders: You can work your upper body, core and lower body all at once by using combination exercises such as a lunge coupled with an overhead dumbbell press and knee lift. That’s not only improving three areas at once, it’s also a stability exercise because you’re balancing on one leg.

You won’t bulk up: Unless you’re pumping iron for hours a day every day or taking supplements, you will not be creating a body-builder frame. This is especially the case for women, who are the most likely to be afraid of becoming too muscular despite not having the testosterone levels of men.

It’s fun and challenging: You can run 10 miles no problem, but can you hold a plank for two minutes? Not only is strength training a test of your fitness (and way to build it), it’s also fun! Once you get started, you’ll notice improvements overt ime. That move that used to seem so hard a couple of months ago now feels easy. You used to only be able to do 10 reps of bicep curls at a given weight and now you can do 15. Your lat pulldowns were set at 55 pounds, now you can handle 70.

For more from Katharine Lackey visit Kat Runs D.C.