Whatever your pace is Costa Rica can match it. Go hard and hike volcanoes, surf famous waves, snorkel/scuba is crystal clear water, river raft through the rapids of the Pacuare, kayak at night through bioluminescent algae, or jump off waterfalls. When you want to take it slower just stop to listen and watch for birds, frogs, iguanas, monkeys, and of course sloths.