What the research actually shows
A 2018 meta-analysis published in JAMA Psychiatry examined 33 randomised controlled trials covering over 1,800 participants. It found that resistance training significantly reduced anxiety symptoms across a wide range of populations, including people with and without diagnosed anxiety disorders.
The effect was meaningful. Participants who trained regularly showed roughly a 20% reduction in anxiety symptoms compared to control groups. Crucially, this held regardless of training intensity: low-to-moderate intensity programmes were as effective as high-intensity ones for anxiety outcomes.
Source: Gordon BR et al. Association of Efficacy of Resistance Exercise Training With Depressive Symptoms. JAMA Psychiatry, 2018.Why does lifting reduce anxiety?
The mechanisms are not fully settled, but several are well supported:
- HPA axis regulation. Resistance training reduces cortisol reactivity over time, meaning your stress response system becomes less sensitive to triggers. You produce less cortisol in response to the same stressors after a period of consistent training.
- Increased GABA activity. Exercise increases activity of gamma-aminobutyric acid, the primary inhibitory neurotransmitter in the brain. Low GABA activity is associated with anxiety disorders. Lifting appears to upregulate GABA pathways.
- Improved sleep quality. Resistance training consistently improves sleep onset and quality in research trials. Sleep deprivation and disruption are major amplifiers of anxiety, so anything that improves sleep has a secondary anxiety benefit.
- Self-efficacy. Lifting something heavier than you could last month produces a concrete, measurable sense of capability. This generalises. People who train consistently report feeling more capable of handling difficulty outside the gym as well.
How long until effects appear? Research suggests mood improvements after a single bout of resistance exercise can last up to 12 hours. Cumulative effects on baseline anxiety tend to appear within 4 to 6 weeks of consistent training, 2 to 3 sessions per week.
Source: Ensari I et al. Meta-analysis of acute exercise effects on state anxiety. Clinical Psychology Review, 2015.Resistance training vs. aerobic exercise for anxiety
Both work. The research does not clearly show one is superior to the other for anxiety outcomes. What matters more than the type of exercise is consistency and effort. If you find resistance training more engaging or sustainable than running, that is the better choice for your mental health, because you will do it.
If you are already doing aerobic exercise and still experiencing anxiety, adding resistance training two to three times per week may compound the benefit through different physiological pathways.
How much do you need to do?
The good news from the JAMA Psychiatry meta-analysis is that even low volumes of training produced meaningful anxiety reductions. You do not need to train like an athlete. Two to three sessions of 30 to 45 minutes per week appears to be sufficient to generate the mental health effects.
Higher volumes and intensities did not consistently produce greater anxiety benefits than moderate training. This means that if your goal is mental health, not physique or performance, you have more flexibility about how hard you push.
What to focus on if mental health is your primary goal
Given that the anxiety benefit does not require maximum intensity, prioritise the factors that make training sustainable:
- Choose exercises you find at least tolerable, ideally ones you like
- Train at a time of day when you are most likely to actually show up
- Keep sessions short enough that they feel manageable, 30 to 45 minutes
- Focus on consistency over months, not perfect sessions each week
The research is clear that the mental health benefits of resistance training come from sustained practice, not from any single intense session. A 35-minute session done consistently twice a week produces far more benefit than occasional intense sessions followed by long gaps.
A note on using exercise alongside other support
Resistance training is a genuine evidence-based tool for managing anxiety. It is not a replacement for therapy or medication when those are indicated. For many people, exercise works best as part of a broader approach rather than as the only strategy. If your anxiety is significantly affecting your daily life, speaking with a healthcare provider is the right first step, not instead of exercise but alongside it.