So use your range. Stick to middle-low range mostly, and if you feel you've "earned" a few calories by being more active, go up in the range.
The thing is, Spark doesn't do that for two reasons. Firstly, your body isn't a 24 hour clock. If you have a big workout day today you might want more calories today - and also tomorrow. But you didn't 'earn' them tomorrow, you earned them today. So it doesn't make sense to just give yourself more calories on the one day you actually did the work.
Secondly, thinking "I exercised so I can eat more" is a bad habit that in many people can lead to a disordered behaviour towards eating and exercising.
Deb, in New Zealand