The aerobics program Get Fit With Jenni was used for almost entirely non-aerobic purposes Tuesday, when Seattle-area 15-year-old Brian Elkins vigorously engaged in a low-impact cardiovascular workout while watching the TV show. Elkins performed his semi-aerobic routine while watching 22-year-old host Jenni Raye, clad in a spandex bikini-top and form-fitting lycra shorts, do hamstring-toning leg lifts while bent over on all fours. 'We have determined that Brian's heart rate increased by about 35 percent during his semi-strenuous nine-minute regimen,' said Elkins family physician Dr. Edward Farber. 'His breathing rate likewise increased, and several large and small muscle groups received a modicum of aerobic movement and stretching.' Elkins, who woke up with minor soreness the next day, said he 'could really feel it working.' 