Task: Question Answering
Input (English): Context: The air is a bit thin , making exercise ( like climbing mountain passes ) a bit of a challenge . We entered the basin via the Grandview Trailhead , with a 4 mile hike back to Betsy Lake where we established camp . Here 's a map of the area : We reached the trailhead at about 11:00 , when the boys decided to have their lunch before hitting the trail . We ate and put the finishing touches on our packs and took off . 
Question: Why did the boys want to have lunch before continuing up the trail ?
Output (English): They wanted to get some fuel in before beginning the main hike.