The Method Weight loss
Cardio or weights to lose weight?
Cardio moves the scale more. Lifting decides what the scale is made of. You want both.
StrongGood evidence, with a caveat worth knowing.
Updated . The Vanguard coaching team.
What most people miss
Asked as a contest, this question has a winner, and it is cardio. In an eight-month trial of 119 sedentary adults with overweight or obesity, the groups doing aerobic training lost more body weight and more fat than the group that only lifted.1
The same trial holds the part most people miss. The groups that lifted gained more lean mass than the group that only did cardio, and the group doing both trained about twice as long without losing any more fat than cardio alone.1 Lifting's job in a diet is not burning fat. It is keeping the muscle while the deficit does the losing.
The fear that cardio eats muscle does not hold up either. Across 43 studies, adding aerobic training to lifting changed muscle growth and maximal strength by effectively nothing.2 Its job is to widen the deficit, so you do not have to eat as little.
So the order of importance runs backwards from how most gyms sell it. The deficit does the losing, cardio makes the deficit easier to hold, and lifting protects what you want to keep.
The research
The papers behind the answer
Each one checked against the paper itself. The grade describes the strength of the evidence, never anyone's results.
Willis, Slentz, Bateman et al., 2012 · J Appl Physiol
Randomised trial, STRRIDE AT/RT · n = 119 sedentary adults with overweight or obesity · 8 months
Aerobic training, alone or with resistance training, cut body mass and fat mass more than resistance alone, and the two were no different from each other. Resistance, alone or combined, raised lean mass more than aerobic alone. The combined group trained about twice as long.
Read the paper by Willis, Slentz, Bateman et al., 2012 (opens in a new tab)Schumann, Feuerbacher, Sünkeler et al., 2022 · Sports Med
Meta-analysis · 43 studies
Adding aerobic training changed muscle growth and maximal strength by effectively nothing. Explosive strength dipped (−0.28), more when both shared a session. A second 2022 analysis found a small cost to fibre growth with running.
Read the paper by Schumann, Feuerbacher, Sünkeler et al., 2022 (opens in a new tab)
Research describes groups of people. Your coach will tell you how it applies to you.
From the floor
Conditioning in the app counts against the same weekly ceiling as the lifting, so adding cardio trims sets rather than stacking fatigue. An easy day has a ceiling it never crosses.
The Vanguard coaching team