The short answer
If your priority is strength or muscle, lift first and do cardio afterwards or on another day. Cardio does not prevent muscle gain: a 2022 meta-analysis found that combining it with strength training did not reduce muscle growth or maximal strength, though it slightly reduced gains in explosive strength. A short warm-up on the bike before lifting is fine.
The order depends on your priority
The exercise you do first gets your freshest energy. For strength and muscle, lift first. If you are training for a run or a race, put the cardio first.
Does cardio kill your gains?
Schumann and colleagues (2022) pooled the studies: adding endurance training to strength training did not reduce gains in muscle size or maximal strength. Only explosive strength progressed slightly less, especially when both were done in the same session.
Separate them when you can
Cardio on another day, or at least six hours apart, limits fatigue. If you do both in the same session, keep the cardio for the end.
Which cardio?
Cycling interferes less with leg training than running, because it has no impact. Walking, cycling and rowing are easy to recover from. Keep hard intervals away from your heavy leg days.
How much a week?
Health guidelines recommend at least 150 minutes of moderate activity a week. For example: three 30-minute bike sessions and daily walks alongside three strength sessions.
Put it into practice
About this guide
STARK editorial guide. Examples explain how to use the library and record training; they are not individual coaching.
Training principles: Schumann et al. (2022), Sports Medicine — concurrent aerobic and strength training.
The session examples come from the STARK program catalogue linked above.