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Limited evidenceMyth check

Cardio kills your gains

Doing cardio alongside lifting does not, in general, cost you muscle or maximal strength. The largest meta-analysis to date found no loss of hypertrophy or 1RM strength from adding aerobic training; the one real cost is a modest blunting of explosive power, mostly when both are done in the same session. Large amounts of running are where interference shows up most.

What the science says

  • Adding cardio reduces muscle growth and maximal strength Limited evidence

    Schumann's 2022 meta-analysis of 43 studies compared concurrent aerobic plus strength training with the identical strength program alone. The pooled effect on muscle hypertrophy was essentially zero (SMD -0.01) and on maximal strength was small and not significant (SMD -0.06), regardless of cardio type (running or cycling), weekly frequency, training status or age.

  • Explosive strength can be blunted Moderate evidence

    The same meta-analysis found a small but significant reduction in explosive strength (SMD -0.28), which was more pronounced when cardio and lifting were done in the same session than when they were separated by at least 3 hours. If jumping, sprinting or power sports matter to you, this is the part of the myth with some truth.

  • Lots of running interferes more than moderate cycling Moderate evidence

    Wilson's 2012 meta-analysis of 21 studies found that concurrent training produced smaller gains in hypertrophy, strength and power than lifting alone, with running (not cycling) linked to lower hypertrophy and strength, and interference growing with the frequency and duration of endurance work. This older analysis is why the myth exists; the newer, larger one suggests that at typical recreational doses the effect on muscle is negligible.

What to do instead

Keep doing cardio for your heart and fitness; manage the dose and spacing so it does not compete with your lifting.

Cardio for most lifters2-3 sessions per week of 20-40 minutes is compatible with muscle and strength gains
Separate the sessionsAt least 3 hours between cardio and lifting, or different days, if power matters
Modality near leg daysPrefer cycling or rowing over long runs when legs are the priority
Same sessionLift first, then cardio (see the exercise-order myth)
Keep the lifting constantDo not cut your weekly hard sets to make room for cardio

Who should be careful

These ranges are for healthy adults. Very high combined training loads raise fatigue and overuse risk; build cardio volume gradually and check with a physician before starting vigorous exercise if you have heart disease or symptoms such as chest pain.

Frequently asked questions

Will cardio make me lose muscle?

Not at usual doses. A 2022 meta-analysis of 43 studies found no loss of muscle growth or maximal strength when aerobic training was added to an identical lifting program.

Is there any downside to combining them?

Explosive strength (jumping, sprinting) gains may be somewhat smaller, especially when both are done in the same session; separating them by at least 3 hours reduced this.

Is running worse than cycling?

An older 2012 meta-analysis found running interfered more than cycling, and that interference grew with how often and how long people did endurance work. The 2022 analysis found no difference by modality.

Scientific references

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