I'm kind of terrified/intrigued about what 'quantified self' might mean for sex (and maybe, online dating).

Imagine a dating site (for short term "dating" like Grindr, or longer term dating in the sense of auditions for a relationship) where "key performance indicators" were measured and attested by the site. Rather than just going by photos (although, standardized photos would be a win), stuff like weight, bodyfat, various health markers, and perhaps "aerobic performance stats", in the context of sex.

"I love you long time!" would have a whole new meaning.

Would probably be too easy to fake. Though you could use reputations.

There are probably ways to get authenticated data/ ensure provenance of data. In person screening centers?

also would be fun to have a second life /mmo type game where characters had substantially the same stats and skills as the players.

"Then the scientists sent the couples home, instructing them to complete at least one sex act a week for a month while wearing the armbands" - so weekly sex and being paid to do it, there should be more tests like these everywhere.

Reminds me that I should probably get some exercise. Or sex for that matter.

"Ninety-eight percent of Karelis’s volunteers reported that sex felt more fun than jogging. The other 2 percent, I suspect, will be back in the dating market soon."

My infrequent 30 minutes jogging = 270 cal, which would translate in one hour + 7 minutes of sex. TL;DR: Wife won't agree to make this a routine.

You must be doing it wrong?

21 couples, 98% said sex is more fun than jogging. So .. 42 persons makes the 2% exactly one individual. Talking about 'percentage' seems misleading.

In addition: What, other than the word 'sex' in the title, is interesting about this article? It seems superficial and .. lacking?

Their procedure seemed a little lacking too. They measured jogging on a treadmill in the lab, then fitted them with 'unobtrusive armband' monitors. Does that measure the same thing as the lab equipment? Why not just use the armbands when on the treadmill, to get a comparable measurement?

Also, people doing Anything while others are watching, do it more deliberately than when private. So they only have conclusions about the activity level when wearing an armband, and while planning what to write in your journal afterward.

"When the researchers analyzed all of the resulting data, it was clear, Karelis said, that sex qualified as “moderate exercise"

Surprise, surprise!