More from Prevention: Get Your Workout Motivation Back Kick up cardio workouts. After age 30, every additional birthday candle that you blow out increases your risk for muscle loss. Which means you’re burning fewer calories, because a pound of muscle naturally burns more calories than a pound of fat. One way to offset this: “Lengthen or boost the intensity of your cardio workouts,” says Austin. “You’ll burn more calories per sweat session.” Her favorite calorie-blaster: Interval walking. “I love it, and it’s really helped me keep off weight after hitting 50.” The best part is intervals are easy and all fitness levels can do them. “All you have to do is change the pace of your walk every two to four minutes, increasing your speed for a few minutes and then dropping back to a more moderate pace for a few minutes, and repeat that series for 30 minutes,” says Austin. “For the speed bursts, do a faster walk or break into a little jog. Just pump it out as best you can.”  More from Prevention: Get A Belly Fat-Blasting Walking Workout [pagebreak] Sneak in strength training. “I’m really into compound exercises because they allow you to double the workout in half the time,” says Austin. “If you’re doing moves that target the entire body, like a squat with an overhead press or a lunge with a bicep curl, you can tighten and tone all your muscles in only 7 minutes.” (Here, get the 5 Best Toning Moves For Your 5 Trouble Spots.) Adopt the 7-to-7 rule. “Another trick that really helps me stay on track is to only eat between 7 a.m. and 7 p.m., Sunday through Thursday,” says Austin, who’s more lax about eating later on the weekends. It’s really made a difference for me because it cuts out a lot of the extra noshing in the evening that can pack on pounds." Tempted to snack? Sip on lemon water or herbal tea. Go green. With your tea, that is. “I really believe that green tea is the key for all of us women who are gaining some weight around your middle,” says Austin, noting that research shows green tea extract may increase your calorie and fat burn. “I think that’s a big part of what’s helped me. I now drink one cup every day.” Plan a food splurge. “I think it really helps if you focus on losing weight one week at a time,” says Austin. “Aim to eat healthy six days out of the week, and then enjoy what I call a ‘super splurge’ on the seventh day. It helps you enjoy yourself and not feel so deprived, so you’re ready to recommit to healthy eating the following week.” Austin normally saves her super splurge for date night with her hubby. “I love to go out with my husband and a few friends on Friday or Saturday. Being from Southern California, Mexican food is my favorite, and I normally splurge on enchiladas and margaritas.” Yum! More from Prevention: The 25 BEST Diet Tips Of All Time!   Get all of Denise’s secrets to getting fit, healthy, and energetic for life in her book,Side Effect: Skinn y.