Why don't you try very very short sessions of interval training some days (e.g. a few sets of burpees) and short lifting (say with a kettlebell) or isometrics (

Why don't you try very very short sessions of interval training some days (e.g. a few sets of burpees) and short lifting (say with a kettlebell) or isometrics (e.g. with a rubber band) sets other days? This won't alter your lifestyle, and it may bring many health benefits with minimal effort. Plus you will experience mental benefits towards those long coding sessions.