Most people who lift also want a working heart and lungs, and the health guidelines ask for both. The question is how to fit them together: cardio first or last, the same day or another, and whether it eats into the gains from lifting. The research has good answers to all three.

The short answer

If strength or muscle is your priority, lift first and do the cardio after, or on another day. Two meta-analyses found more lower-body strength when the weights came first, while muscle growth and aerobic fitness did not depend on the order. Combining the two costs little: a 2022 review of 43 studies found no loss of muscle or maximal strength, only of explosive power when both shared a session. Aim for the guidelines: 150 to 300 minutes of moderate cardio a week, plus strength training on two or more days.

Does cardio cost gains?

Not much, and less than its reputation says.

  • Muscle and maximal strength hold. A 2022 meta-analysis of 43 studies compared strength training alone with the same strength training plus aerobic work: no difference in muscle growth or maximal strength. Explosive strength, the kind a jump or a sprint needs, gained less, mostly when the two were done in the same session, and not when they were at least three hours apart.
  • The amount matters. An earlier meta-analysis of 21 studies found that the more often and the longer people did endurance training, the smaller their gains in muscle, strength and power tended to be. In that analysis running cost more than cycling, although the 2022 review found no difference between the two.
  • The position stand is cautious. The American College of Sports Medicine’s 2026 position stand found too little data to say how aerobic work in the same session changes strength.

Before or after, in one session

  • Lifting first builds more leg strength. A 2018 meta-analysis found a lower-body one-rep maximum about 4 kg (9 lb) higher when strength came before endurance, with no effect of the order on aerobic capacity. A second 2018 meta-analysis of 10 studies found about 7 percent more lower-body strength with lifting first, and no effect of the order on muscle growth, aerobic capacity or body fat.
  • Close together is the real cost. The 2022 review found no effect of the order itself once the studies were pooled: what hurt explosive strength was doing both close together.
Your priority Plan it this way
Strength or muscle Lift first, cardio after or on another day
Endurance, such as a race Cardio first, or on a day of its own
Health, both alike Either order; aerobic fitness and body fat did not depend on it
Jumping or sprinting power Separate sessions, at least three hours apart

How much cardio

The WHO guidelines ask adults for 150 to 300 minutes of moderate aerobic activity a week, or 75 to 150 of vigorous, plus muscle-strengthening activity for all major muscle groups on two or more days. Moderate means an effort of about 5 or 6 on a scale of 0 to 10; walking, cycling, swimming and running all count. A lifting week can hold it in several ways: three sessions of 50 minutes, five of 30, or short finishers after lifting plus longer sessions on the days between.

What it means for your week

Fat Loss Strength and Cardio, 4 days is built the lift-first way. Each of its four days starts with the lifting and ends with a short finisher: 10 minutes on the Rowing Erg, three 2-minute rounds of the Jump Rope, three sets of the Burpee, or the Walking Lunge and 40-second Mountain Climbers. By our count those finishers add about 20 minutes of cardio a week, a top-up rather than the whole guideline, so the rest belongs on the days in between.

Full-Body Conditioning Circuit, 3 days takes the other route and mixes both in one round: kettlebell swings, push-ups and squats run straight into two minutes of rope. That puts fitness first, which is what the program is for. How many days to lift, and where the cardio days fit around them, is in How Many Days a Week Should You Work Out?

How to apply it

  1. Decide the priority. Lifting first for strength and muscle; cardio first only when endurance matters more.
  2. Keep the finisher short after a lifting session: 10 to 20 minutes.
  3. Put longer cardio on other days, or at least a few hours after lifting.
  4. Keep hard intervals away from the day before heavy squats.
  5. Count the week, not the session: 150 minutes of moderate cardio, two or more lifting days.

Trenno logs cardio beside the lifting: the Rowing Erg takes its time and distance and works out the pace, and an interval such as the Jump Rope takes its minutes. On Apple Watch the heart rate stays on screen through the session, and the summary shows its average and maximum. With the Health options on, a run or a ride logged in another app adds its share to Trenno’s recovery estimate.

Mistakes and myths

  • “Cardio kills your gains.” In 43 studies it did not cost muscle or maximal strength.
  • “Cardio first burns more fat.” The order made no difference to body fat.
  • A hard run right before squats. Leg strength gained less when endurance came first.
  • Only finishers. Ten minutes after lifting is a start, not the 150 the guidelines ask for.

FAQ

Should I do cardio on rest days?

Yes, at an easy or moderate effort. It keeps the lifting days for lifting and puts hours between the two.

Does cardio before lifting count as a warm-up?

Five easy minutes, yes. A hard 20 minutes is a workout of its own, and over months, cardio before lifting cost leg strength in the studies above; Warm-Up Sets covers the warm-up that prepares the lifts.

Is cycling better than running for lifters?

One meta-analysis found running cost more strength and muscle than cycling; the 2022 review found no difference. Pick the one you will keep doing, and keep hard runs away from leg days.

How long should cardio after weights be?

Short. Our fat-loss program’s finishers run from about 2 to 10 minutes of work; keep it under 20, and put longer sessions on days of their own.

Sources