previous data point (i.e., q->secs - p->secs), the duration to multiply
the wattage value by SHOULD NOT be. Instead, should multiply by
rec_int. (My ride from Jul 31, 2007 demonstrates the problem. I
started an interval with a 1-sec wattage of 773 after a ~48 second rest.
Using the old code, that gets credited as 773 watts for 48 secs!)