Rachel Cosgrove on the Female Body: Start With Strength Training

Author and fitness pro Rachel Cosgrove says hours on the treadmill are not going to do much good.


When women say they need to do more exercise, they're usually thinking of aerobic activity: running, a spinning class, speed-walking. But making aerobic workouts the centerpiece of a fitness plan is not the best way to go, says Rachel Cosgrove, cofounder of Results Fitness in Southern California. In her new book, The Female Body Breakthrough, she instead advocates a focus on strength training, which she says is the real key to losing fat and looking better. U.S. News recently chatted with Cosgrove. Here are edited excerpts:

First, why is running at a steady pace not a great workout?

The bottom line is that our bodies adapt. If you do a mile run today, when you do the same mile run tomorrow and the next day you're going to burn fewer calories. But with strength training, you can increase weight, or add more sets, or do more reps. You should put in a new demand every single workout. But don't a lot of public-health recommendations, including those from the government, recommend 150 minutes a week of aerobic activity?

Well, your heart rate will also go up during my strength-training program because the rest periods are fairly short. Your heart still has to pump. In fact, doing strength-training exercises [in quick succession] raises your heart rate to a level beyond what you'd have in a steady-state workout. Say I like the idea of running for stress relief, if not for a better bod. Why is it not a great idea to go straight from the sofa to the streets?

If on Day 1 of your running routine you ran a mile, that would be about 1,500 steps. If you walked into the gym and we said, "Let's start with 1,500 plyometric jumps on one leg," it would be crazy. It's a route to getting injured, depressed, and discouraged. I'm not saying never run; doing an endurance event is a great way to challenge yourself and help you realize you can accomplish anything you want to. [Cosgrove has completed an Ironman triathlon.] But do some strength-training first; be sure you can handle those repetitive motions. [Check out Ready to Give Running a Try? Here's How.]

Why do women need a different strength-training workout than men?

They tend to be more quad-dominant than men [meaning they use the quadriceps more than the butt and hamstring muscles]. It's a real weakness for a lot of women; they have what I call "gluteal amnesia" because their brains aren't used to switching on their butt muscles. We also have wider hips, and our pelvis tips forward, which stretches the hamstrings and makes it harder to engage the glutes. By engaging the core, you can pull your pelvis under you and stretch out your hip flexors. You can do exercises that will switch on the butt muscles and hamstrings. And why is it so important to use weights that are relatively heavy?

In order for your body to change, you have to put demands on it that it's not used to. Women often use weights that don't challenge them. But the goal is to be strong and fit and toned, but feminine. You will have muscle definition, but you'll also get smaller. You say women should use free weights, not fixed machines. Why?

Well, one rule of thumb is that you don't go to the gym to sit on your butt! Most of us don't need to sit down any more than we already do. And by standing on your own two feet, using your core muscles and your whole body, you'll get more out of it. With free weights, using your whole body, you're doing motions that are present in real life, not that fixed plane of motion [you get in with a machine]. And machines switch off all your stabilizer muscles—they do the work for you. As [the big muscles you are targeting] get stronger and stronger and your stabilizers don't, that can create problems. How important is diet relative to exercise if your goal is to look better?

Diet and exercise really go together. I describe it as a three-legged stool: You need a good mind-set, good nutrition, and exercise. If you take one of those away, it's not going to work. [Read 10 Week Workout Routine: What About Diet?]

But you don't advocate counting calories; instead, you say to eat well 90 percent of the time and enjoy the other 10 percent.

That's a long-term approach, not a diet I'm going to do for 12 weeks only. You can definitely fit those splurges in; life is too short to be dieting and beating yourself up. The problem is if you get into the mind-set of, "Well, if I don't follow this 100 percent, I'm off the plan, and I may as well just blow it." [Check out a slide show of 6 stupid holiday diet tips you should ignore—and 1 you shouldn't.]