A recent study from NPD shows that one in five consumers want a fitness device that they can hook up to their PC. Today’s question is “will people have more incentive to actually buy these devices if they can use them with friends”.

Striiv, a smart pedometer that caters to casual exercisers who like rewards, thinks that collaboration with a friend is going to increase the likelihood of using your device effectively. Last year the company introduced a pedometer that allowed the user to either win game play or make a donation to charity upon meeting goals.

The new version released this week adds the “friend” element. You can now see your goals and progress side by side with others in your group. Dan Wang, the company CEO calls it the “social pedometer” where the motivation comes from games, rewards, friends and charity.

Other devices like BodyMedia, Fitbit, and Jawbone focus on data analysis – tracking your movements. Fitbit keeps a record of caloric intake, BodyMedia does that plus tracks sleep. Jawbone now lets users post a food photo diary to share with others, and offers online incentives.

More serious athletes turn to devices from Polar and Garmin. Polar offers built-in coaching as well as endurance and recovery time training in their devices. Garmin offers special devices for runners, cyclists and even golfers.

The benefits of using technology to monitor your workouts have become nearly undisputed. But is monitoring yourself with friends more effective than going solo? 

Research presented in the Economist gives examples of group training being more effective (the secret is endorphins). And the Telegraph in the UK found similar results. Women in particular do better exercising with friends, says a Motley Fool advice column. On average, their article finds a women will lose 10 pounds more if they exercise and diet with a female friend, and that 20% of women that exercise alone do not lose any weight at all.

So which type of fitness buff are you? The lone Rocky Balboa or the grab a buddy and go?