Training

Strength training for women: five myths, checked against the research.

By Luigi · 4 min read

A lot of the advice about strength training for women was never based on research in the first place. It was based on magazine covers. Light pink dumbbells, "toning", and a quiet worry that picking up anything heavy will turn you into someone you didn't sign up to be. So I've taken the five myths I hear most often and checked each one against what the studies actually show.

A quick note on the evidence before we start. Women have been under-represented in exercise science for decades, so some of these questions have less data behind them than they should. Where it's thin, I'll say so.

Myth 1: "Lifting will make me bulky"

This is the big one, and it's mostly a misunderstanding of how slowly muscle grows. A 2025 meta-analysis pulled together 29 studies where men and women aged 18–45 did the same training programme^[1]. Men gained slightly more muscle in absolute terms, mainly in the upper body. But relative to where they started, the gains were similar between the sexes.

So the honest answer isn't "women can't build muscle" — they can, and that's the point. It's that muscle comes on slowly, for everyone, and only if you train hard, eat enough and keep going for months. Nobody accidentally ends up looking like a bodybuilder from two sessions a week. What people tend to notice first is that they look firmer and feel stronger. That's muscle, and it's exactly what "toned" means.

Myth 2: "Women don't respond to weights as well as men"

The opposite, if anything. An earlier meta-analysis compared men and women on identical programmes and found similar muscle growth and similar relative gains in lower-body strength^[2]. For upper-body strength, women actually improved more in relative terms. The authors are cautious about why, and most of the studies were short and in untrained people, so I wouldn't read too much into the size of that gap.

Honesty note: references 1 and 2 share an author, so they aren't fully independent. But they used different sets of studies and different methods, and landed in the same place.

Myth 3: "Stick to light weights and high reps to tone up"

Half true, which is why it hangs around. A network meta-analysis of 28 studies compared low loads (more than 15 reps), moderate loads (9–15) and heavy loads (8 or fewer), with every set taken to failure^[3]. Muscle growth was similar whichever load people used. Strength was a different story: moderate and heavy loads beat light ones clearly.

So light weights can build muscle — but only if the set is genuinely hard by the end, not 20 easy reps while chatting. And if you want to get stronger, which is what makes carrying the shopping, the kids and the suitcase easier, you need some heavier work too. In practice I use a mix, and the weights go up as you get stronger.

Myth 4: "I need to plan my training around my cycle"

This one has grown a whole industry of apps, so it's worth being careful. A large meta-analysis of 78 studies found that performance might be trivially lower in the early follicular phase (around your period) than at other times^[4]. The key word is trivial. The authors rated the evidence as low quality and concluded that general rules can't be drawn — they recommend a personal approach instead.

A later umbrella review, looking across the published reviews, went further: it said it's premature to conclude that cycle phase meaningfully affects strength or long-term gains from training^[5]. These two share an author, so read them as one strand of evidence rather than two.

What that means in practice: there's no need to rewrite your programme by the calendar. But if you feel rubbish on certain days, that's real for you and we adjust on the day. That's not a cycle-syncing plan. It's just good coaching.

Myth 5: "Weights are optional — cardio is what counts for health"

A meta-analysis of 16 prospective cohort studies found that adults who did muscle-strengthening activities had a 10–17% lower risk of dying early from any cause, and of heart disease, cancer and type 2 diabetes, independent of their aerobic exercise^[6]. The biggest benefit showed up at around 30–60 minutes a week, and doing both strength and cardio looked better than either alone.

Two caveats. That's observational data, so it shows a link, not proof. And it covered adults in general, not women specifically. But it's a strong reason to treat strength work as part of your health, not an optional extra for people who want to look a certain way. If you're weighing the two for fat loss, I've covered that in cardio or weights for fat loss, and why muscle matters more each decade in muscle after 50.

What I actually tell women starting strength training

• Train the same way men do. Squat, hinge, push, pull, carry. The programme is built around you, not your sex.
• Lift heavy enough that the last reps are hard. Whatever the weight, the final few reps should be a real effort.
• Let the weights go up. Strength gains are the clearest sign the plan is working. If the weights haven't moved in two months, the plan needs to change.
• Listen to your body, not an app. Bad days happen, for all sorts of reasons. We adjust on the day.
• Pregnant or postnatal? That needs its own approach — see my pre- and postnatal training page.