Just out of curiosity, what kind of strength exercises are you doing?
mostly body weight things.
core: tuck-ups, flutter-kicks, front/side/back planks, seated medicine ball twists (usually without ball). ~8mins total.
legs + t-rex-style arms: 1-legged squats, lunges, calf raises, leg curls/extensions (on machine), sideways leg lifts, pushups, pullups, sometimes bench dips. ~8mins per set, up to 3.
the leg stuff in particular sometimes makes me sore or tight, which also causes lower-quality sleep as a result. so I often do less than 3 sets depending on races, motivation, time, or other excuse-making.