Is it possible to give more than 100% ?

On December the 31st there was the annual "Innsbrucker Silvesterlauf". As far as my only official Running Event this year was the "Innsbrucker Stadtlauf" I decided to participate this run. 5.3 Kilometers is not much so I gave my best. The first look on my Heart-rate monitor was not good. Because of formula: 220 minus Age, I calculated a maximum heart rate of 192 bpm. My heart rate was on 96% capacity. 5 minutes later I looked again on my HR-Monitor --> 107%.
At this point I decided not to look again on my HR. After the race the HR-Monitor asked me, if I want to change my max. Heartfrequency from 192 up to 207.