When asked to choose one high-tech gadget or device that they'd recommend above all others, these athletic trainers offered up the following selections -- backed by personal experience. Gadgets and machines have become as embedded in the fitness culture as sneakers and sweats. Although it's possible to get a decent workout with nothing more than a couple of dumbbells and a jump rope, high-tech contraptions help exercisers work smarter, not harder. We asked three trainers for their must-have selection and the best ways to incorporate it into a fitness program. Pete McCall, a San Diego-based trainer and exercise physiologist with the American Council on Exercise, chose a heart rate monitor. Gina Lombardi, a Los Angeles-based personal trainer, selected a vibration plate. And Ramona Braganza, a Los Angeles-based personal trainer and member of the Gold's Gym Fitness Institute, opted for a pedometer. Pete McCall Recommendation: Heart rate monitor Heart rate monitors are good for someone just starting to exercise, because it helps them be much more effective with time. And they're pretty user-friendly. If you're training to improve your base level and build endurance, you want to train at a lower level and not overtrain. To make sure you're working at an aerobic level, do a talk test -- exercise at a fast pace, and say something relatively short, like the Pledge of Allegiance. When you can no longer say it effectively, note what your heart rate is. That would be the crossover point from working at an aerobic level to an anaerobic level, or from burning fat as a fuel source to burning carbs. Let's say your crossover point is 120. Once you establish that, you know where the high end of your aerobic level is. When you want to do interval training to improve cardiovascular function, you can do two minutes in your anaerobic zone and then two minutes in your aerobic zone. Using the heart rate monitor you can gauge your intensity much better. It always amazes me -- you see people working as hard as they can going crazy, making themselves breathless, but elite-level athletes like cyclists and runners spend about 70 percent to 80 percent of their time in their aerobic zone to build endurance. I started using heart rate monitors when I started to teach spinning classes because they can monitor your training intensity in class. I always laugh when students say the class wasn't that hard, and I tell them they're right -- but they'll be able to work out tomorrow. If you overtrain, it can disrupt sleep patterns and put stress on the body. Having a heart rate monitor allows people to listen to their body. Gina LombardiRecommendation: Vibration plate I'll ask someone to keep their legs straight and touch their toes and they can't do it, but they'll get on the vibration plate for 30 seconds and they'll be able to do it. Most people are inflexible in their hamstrings and lower back. I've also had people get on there and do fairly easy yoga poses and it tremendously increases their flexibility. I recommend using it just twice a week to start and beginning on a low frequency -- don't do it with every workout, because you have to get used to it. Ideally you should first try it with a trainer who knows how to use the machine. The most obvious improvement people usually see is in flexibility. Second is strength. I had one female client who couldn't do one regular push-up after weight training for a couple months. After I put her on the platform, she could do 10 push-ups after one week. Women are always the underdogs when it comes to upper-body strength, so it's nice to get the upper edge. Studies have shown that people who used the plate increased their power output and their strength. That's huge, and it can apply to the average Joe who goes into the gym and wants to get more flexible and strong. Just by doing a few 30- to 60-second intervals on the platform they're able to increase their strength and power, and it gives them that instant gratification that everyone wants. Ramona Braganza Recommendation: Pedometer Pedometers are great -- they not only track your steps, but some also log your miles and have an auto reset and will count your steps for seven days. I think they work so well for losing weight and getting in shape because if you wear it all day long, from the minute you get up, you'll probably reach your goals. And if you don't, it will motivate you to walk your dog in the evening to get in some extra steps. They're very easy to use and they're not at all intimidating. Some reset at zero in the morning, and that's about as easy as it gets. I've been using one for about a year and a half. I'm a little older now, and my activity level started to suffer. It made me realize that running around every day in a normal fashion is exercise. I also take it on my hikes because I like to see how far I've gone. When I walk for exercise, I like to make it more like a power workout. You can do interval training, walking fast and then slow, and adding some hills, mixing it up. 