Wearable gadgets give rise to extreme tracking

San Diego

FROM the instant he wakes up each morning, through his workday and into the night, the essence of Larry Smarr is captured by a series of numbers: a resting heart rate of 40 beats per minute, a blood pressure of 130/70, a stress level of 2 per cent, 8,000 steps taken, 15 floors climbed, eight hours of sleep.

The astrophysicist and computer scientist could be the world's most self-measured man. For nearly 15 years, the University of California at San Diego professor has been obsessed with what he describes as the most complicated subject he has experimented on: his own body.