It’s one of the most common questions in any gym: should a workout start with weights or with cardio? The answer isn’t universal, and it depends largely on what a person is actually training for that day.

The general rule among trainers is to prioritize whichever goal matters most in that specific session. If building strength or muscle is the primary focus, lifting weights first makes the most sense. Strength training requires the nervous system to be fresh in order to lift with proper form and full effort, and starting with cardio can pre-fatigue the muscles needed for heavier lifts, reducing both performance and the quality of the strength stimulus.

On the other hand, if the main goal is building endurance or improving cardiovascular performance, whether that’s training for a race or simply improving overall stamina, cardio should typically come first. Doing a heavy strength session before a long run or bike ride can leave the legs fatigued and compromise both form and endurance output, since the body is being asked to perform a demanding cardio task on tired muscles.

There’s also a middle ground for people who want to do both in the same session without a specific event to train for. A short, light cardio warm-up, five to ten minutes at a low intensity, can help raise the heart rate and prepare the muscles for lifting without draining energy needed for strength work. Saving more intense cardio, like intervals or a longer run, for after the strength session preserves both the safety and effectiveness of the lifts.

Some research also suggests it’s worth separating the two entirely when possible. Training cardio and strength on different days, or at different times of the same day, allows for full effort and better recovery in both areas, since neither is being asked to perform on top of pre-existing fatigue.

Ultimately, the “right” order comes down to individual goals rather than a fixed rule. Someone chasing a personal best in the deadlift and someone training for their first 10K need very different approaches to structuring the same hour in the gym. Identifying the primary goal for each session, and building the order of the workout around that priority, is a far more effective strategy than following a one-size-fits-all rule.