One of the very best ways to get more out of your workout is to wear a heart rate monitor. It's like bringing a tiny personal trainer along for the ride (or run, or skate), one who doesn't hesitate to let you know when you're either slacking off or pounding the pavement a little too enthusiastically. Who doesn't need that? Recently, I discovered two new monitors—each with an ingenious extra—that deserve a second look.

Sportline DUO 125

What's special about it: You can use it with or without a chest strap. Need constant feedback during a serious sweatfest? Use the strap. Prefer to go strapless and check your heart rate periodically during a less intense session? No problem: The watch acts as a fingertip monitor, so just touching a single finger anywhere along the edge of the face will give you a reading. It's a brilliant combo.

Other things to like: The watch indicates where you are in your chosen heart rate zone, and you can set an alarm to go off when you drop out of it (talk about motivation!). Plus, the under-$100 price is right.

What's not so great: Looks-wise, it's pretty utilitarian and a little clunky, but I've seen worse.

Suunto M4

What's special about it: Pick either fitness or weight loss as your goal, and the monitor will devise a plan to get you there. Each day, it tells you what your workout should look like in terms of length and intensity (it also provides a 7-day overview so you know what's coming up). If you get off-track—say, that 30-minute power walk ends after 10 minutes when you run into your super-chatty neighbor—it automatically recalculates, GPS-style, to create a new plan.

Other things to like: It's cute in a round, retro sort of way, with an easy-to-read oversize face. And if you're not in a goal mood, you can set the monitor to "free training" and just do your own thing.

What's not so great: It comes with just a bare-bones "quick guide"—you have to go online for the full instructions. That's easy enough, but a bit of a pain when all you want to do is get out the door for your morning run.

Products: Sportline DUO 1025 and Suunto M4

Category: Gear

Cost: $89.99 at; $149 at