Mistake: You Go From Zero to 60
If you're late for class and start lifting and hoisting weights without easing into it, you can wreak havoc on your system, says Dr. Higgins. "The physiological and chemical changes that normally happen with exercise can be more pronounced when you jump into an aggressive routine." A release of inflammatory chemicals occurs, including thyroid hormones and cytokines (inflammatory proteins), which impact the immune system and make it more difficult to recover, says Dr. Higgins.
The fix: Ease into a routine for 5 to 10 minutes of easy lifting or moderate cardio before going all out. If 10 minutes is all you have, try one of these 10-minute toners created by Prevention fitness expert Chris Freytag.
More: 15 Minutes to a Better Body
Mistake: You Only Use Machines
If you hop on machines for your entire resistance training program, you should add a dumbbell move or two for a greater anti-aging impact, says Holland. "It comes down to functionality and strength for everyday life activities." Machines lock you into place and stabilize your body, which is fine for beginners, but it doesn't require working in all planes of motion or using stabilizing core muscles, says Holland. "Free weights enable you to be as strong and fit as you can be and strengthen you optimally." In addition, free weights require balance, an ability that diminishes with age.
The fix: Alternate free weights one day and then machines the next time you work that same body part. For example, on a machine day, use the chest fly machine, but then swap in dumbbell chest presses at your next workout. Or, when working your back, use the seated row machine one day and dumbbell rows the next time.
More: 4 Dumbbell Exercises to Build Fast Muscle
Mistake: You Don't Include Power Moves
Professional athletes aren't the only ones who need power. Defined as the ability to exert force in a short amount of time, we use power to get out of the way of a swinging door, dodge a hole in the sidewalk, and to make it across the street before the light turns red, says Holland. "Problem is, we do fewer of these activities as we age, which results in a loss of fast-twitch muscle fibers over time. We lose the ability to react quickly."
The fix: Simply adding a power move to your regular workout helps: Perform a squat by lowering normally and then quickly standing up and rising up onto your toes; or lower yourself into a lunge at a moderate tempo and explosively return to your starting position.
More: Interval Workout to Boost Performance
Mistake: You Stick With Low-Impact Workouts
Biking, the elliptical, and low-impact aerobic classes are great cardio workouts, but they don't do much for your bone density. To stave off osteoporosis, you'll need some impact, says Andrews. "Impact is an integral part in maintaining bone health: The impact travels up the leg and is absorbed at the hip, thus helping prevent hip fracture after menopause." In fact, a recent study published in the journal Medicine and Science in Sport and Exercise showed that running significantly reduced osteoarthritis and hip replacement risk.
The fix: Add impact to your routine with jogging, sprinting, and jumping rope. (Not a runner yet? Here's a stress-free way to become one in just 6 weeks.)
More: Skip Away the Pounds: 10-Minute Jump Rope Workout
Mistake: You Buy Bargain Sports Shoes
Who doesn't love a good sale? But it's one thing to buy that bargain purse, and another to cut corners on fitness shoes. "Cheap shoes that aren't biomechanically correct or suited for specific activities will potentially create imbalances in your lower legs and could lead to back injury," says Holland. Tennis shoes, for example, are designed to support your foot side to side as well as back and forth, whereas running shoes are designed to help you move forward. "The wrong shoes could also cause you to roll your ankle," Holland says.
The fix: Find the best shoes for your workout with our ultimate 2013 Sneaker Guide.
More: How to Pick the Right Shoes for You
Stay in shape in a fitness class.