/**
  * Set activityID if empty
  * Floor must be used because we don't save seconds for activities (historical)
  */
 private function setActivityID()
 {
     if (!$this->TrainingObject->hasActivityId()) {
         $this->TrainingObject->setActivityId((int) floor($this->TrainingObject->getTimestamp() / 60) * 60);
     }
 }