Should you do cardio while bulking? What meta-analyses say about the interference effect, the best type and amount of cardio, and when to do it.
Yes, you can do cardio while bulking. A 2022 meta-analysis of 43 studies found that adding aerobic training to strength training did not reduce muscle growth or maximal strength. Keep it moderate: 2 to 3 sessions a week, favor cycling or walking over lots of running, do it after lifting or on separate days, and eat a little more to cover the extra calories.
You are eating more to build muscle, and you have heard that cardio "kills gains." At the same time, you do not want to lose your fitness or feel out of breath walking up stairs by the end of a bulk.
The good news is that the research on combining cardio and lifting, called concurrent training, is more reassuring than gym lore suggests. The details matter, though: the type, amount, and timing of your cardio all play a part.
Yes. Moderate cardio while bulking does not appear to hold back muscle growth, and it keeps your heart and lungs in shape. A 2022 meta-analysis by Schumann and colleagues pooled 43 studies comparing strength training alone with the same strength training plus aerobic training. Muscle growth and maximal strength were no different between the two, with standardized mean differences of -0.01 and -0.06.
The one thing that did suffer was explosive strength, such as jump and sprint power. That matters for athletes more than for lifters chasing muscle size.
| Question | What the research says |
|---|---|
| Does cardio reduce muscle growth? | Not on average (Schumann 2022, 43 studies) |
| Does cardio reduce max strength? | Not on average (Schumann 2022) |
| Is cycling or running better? | Cycling showed less interference in two meta-analyses (Wilson 2012; Lundberg 2022) |
| Does HIIT hurt muscle growth? | No difference in hypertrophy (Sabag 2018) |
| Lift or cardio first? | Lifting first gave about 4 kg more lower-body 1RM (Murlasits 2018) |
No, not in normal amounts. The idea comes from older research on the "interference effect." A 2012 meta-analysis by Wilson and colleagues pooled 21 studies and found a smaller effect size for muscle growth with concurrent training, 0.85, than with strength training alone, 1.23. Interference grew with the frequency and duration of the endurance training.
Newer and larger analyses are more reassuring. A 2016 review by Murach and Bagley argued that the evidence for an interference effect on muscle growth in humans is not as strong as long believed. Schumann 2022, with twice as many studies as Wilson, found no difference in whole-muscle growth.
There is one caveat. A 2022 meta-analysis by Lundberg and colleagues looked at muscle fiber size in 15 studies and found a small negative effect of concurrent training, with a standardized mean difference of -0.23. So very large amounts of cardio may cost a little growth at the fiber level, even if whole-muscle size looks the same.
Cycling, walking, and other low-impact cardio are the safest choices while bulking. In Wilson 2012, running combined with lifting led to significant drops in muscle growth and strength, while cycling did not. Lundberg 2022 found a similar pattern at the fiber level: the negative effect on type I fibers showed up with running but not cycling.
Schumann 2022 found no difference between cycling and running for whole-muscle growth, so a few runs a week are fine. If you love running, keep it, but keep the volume moderate.
No. High-intensity interval training (HIIT) does not appear to hurt muscle growth when combined with lifting. A 2018 meta-analysis by Sabag and colleagues found that HIIT plus resistance training led to similar muscle growth and upper-body strength gains as resistance training alone. Lower-body strength gains were slightly smaller, with an effect size of -0.248.
HIIT is time-efficient, but it is also hard on your legs. Keep hard intervals away from the day before a heavy leg session.
Two to three moderate sessions a week, or daily walking, is a sensible amount for most lifters on a bulk. The World Health Organization recommends at least 150 minutes of moderate-intensity physical activity per week for adults, which you can reach with brisk walks or easy bike rides.
Wilson 2012 found interference rose with the frequency and duration of endurance training, so the risk comes from doing a lot, not a little. If your lifts start stalling and your legs always feel heavy, cut the cardio back before you cut your lifting.
Do cardio after lifting, or on a different day. A 2018 meta-analysis by Murlasits and colleagues found that lower-body one-rep max improved by about 4 kg more when strength training came before endurance training in the same session. Aerobic fitness improved the same either way.
Schumann 2022 also found that explosive strength suffered more when both were done in the same session than when the sessions were at least 3 hours apart. If you can, put cardio on rest days, or lift in the morning and do cardio in the evening. A push/pull/legs split leaves easy room for cardio after upper-body days.
Yes. Cardio burns calories, so you need to eat a little more to keep gaining at the same rate. The simplest way to adjust is to watch your weekly average body weight instead of guessing how much each session burned.
If your weight stops rising for two weeks after adding cardio, add about 100 to 200 calories a day. Our guide on how many calories to eat to bulk explains how to set and adjust your surplus. If you struggle to eat enough as it is, keep cardio light, as covered in our guide on how to bulk up as a skinny guy.
Alexandros is an iPhone app that works like a personal lifting coach you talk to. You log your lifting sessions in plain English, like "squat 3x8 at 205, last set hard," rate how each set felt, and it tells you what to lift next time using double progression. If adding cardio starts eating into your lifting and a lift stays flat for three sessions in a row, it plans a deload, and you can ask how your squat is trending to see charts computed from your own log.
It also remembers your schedule and preferences, like "I cycle on Tuesdays and Thursdays," and lists that memory in Settings where you can edit it. Alexandros is in early access; its terms say certain features require a paid subscription through the App Store.
Not in moderate amounts. A 2022 meta-analysis by Schumann and colleagues found no difference in muscle growth between strength training alone and strength training plus aerobic training.
For most lifters, yes. About 20 to 25 minutes of brisk walking a day gets you to the World Health Organization recommendation of at least 150 minutes of moderate activity per week.
Not in moderate amounts, but running has shown more interference than cycling in some meta-analyses, including Wilson 2012. Keep the volume moderate and away from heavy leg days.
Keep most sessions moderate in length. Wilson 2012 found that longer and more frequent endurance training was linked with more interference, so a few shorter sessions beat daily long ones.
Yes, rest days are a good time for easy cardio. Schumann 2022 found less interference with explosive strength when cardio and lifting were at least 3 hours apart.
