two options for me :
1. walking every day from 30 up to 60 minutes
2. ive read, and have done it myself, to keep up what you have achieved conditioning wise, keep the intensity of your conditioning session but cut volume significatly, i.e if you normally do 20 hill sprints after workout, do 8-10 and call it a day, besides if you do them 4 times a week do them only twice and as far apart as possible. That way you will rest and deload without compromising your conditioning levels.
edit: this is based on :
" Hickson,R.C.et al. (1985) REduced training intensities and loss of aerobic power,endurance and cardiac growth " + reduced training duration effects on aerobic power endurance and cardiac growth"