Cardio vs strength training for women over 40: which comes first?

You need both, but if you only have time for one thing you're not doing yet, for most women over 40 it's strength training. The US guidelines ask for two muscle-strengthening days a week on top of 150 to 300 minutes of moderate cardio such as brisk walking. Far fewer women do the strength part, and it's the part that works on the muscle and bone that thin with age. Cardio does more for your heart and lungs, and in trials it took more fat mass off. Done together, they don't cancel each other out.

Below: what each one does, with the studies behind it, what the research doesn't show, how to fit both into a normal week with 15-minute sessions, and which cardio is easy on the knees.

The short answer, side by side

Every number in this table has its study below. They're averages across many people, not a promise of what will happen to you.

What the guidelines actually ask for

The US Physical Activity Guidelines ask adults for 150 to 300 minutes a week of moderate aerobic activity, or 75 to 150 minutes of vigorous activity, and muscle-strengthening activity of moderate or greater effort that works all major muscle groups on 2 or more days a week [HHS, 2018]. The World Health Organization's 2020 guidelines set the same aerobic range and also recommend regular muscle strengthening [WHO, 2020]. Both say some activity is better than none.

So the question isn't really "cardio or strength". The guidelines ask for both. The useful question is which one you're missing, and for most women it's strength.

The CDC's national survey shows how wide the gap is. In 2020, 20.4% of US women met both guidelines, against 28.3% of men, and the share fell with age: 22.7% of women aged 35 to 49, 17.6% at 50 to 64 and 10.8% at 65 and over [CDC NCHS, 2020]. Walking is the habit many women already have. Two short strength sessions are usually the missing half.

What strength training does that cardio doesn't

It keeps and builds muscle. Inactive adults lose an estimated 3 to 8% of muscle mass per decade [Westcott, 2012]. A review of 49 studies in adults 50 and over found resistance training added about 1.1 kg (2.4 lb) of lean mass on average [Peterson, 2011], and a review of 47 studies found strength gains of about 24 to 33% on common lifts [Peterson, 2010].

Cardio doesn't do the same job. In STRRIDE AT/RT, a Duke University trial, 119 sedentary, overweight adults were assigned for 8 months to aerobic training, resistance training or both. The two groups that lifted gained more lean mass than the aerobic-only group [Willis, 2012].

It loads bone. Bone responds to force, and lifting puts far more of it through the hips and spine than walking. In the LIFTMOR trial, 101 women past menopause with low bone mass did 8 months of supervised heavy lifting plus jumping, twice a week, and gained 2.9% bone density at the lower spine, while the comparison group on a light home program lost 1.2% [Watson, 2018]. Two cautions: those heavy loads were supervised and built up step by step, and the women already had low bone mass. Our guide on whether weight lifting helps bone density covers what that means at home.

It makes everyday moves easier. Stairs, carrying shopping, getting up from the floor: these are strength jobs. The LIFTMOR group also improved more on function tests such as standing up from a chair.

What cardio does that strength training doesn't

Heart and lung fitness. This is cardio's own job. In a trial of 160 older adults on a weight-loss program, peak oxygen use, a standard measure of fitness, rose more in the groups doing aerobic training than in the group doing resistance training alone [Villareal, 2017].

More fat mass off. In the same STRRIDE trial, the aerobic group and the combined group lost more body mass and fat mass than the resistance-only group, and the combined group didn't lose more than aerobic alone [Willis, 2012]. The authors' own summary: aerobic training was the better choice for fat mass, and a program including resistance training was needed for lean mass. We don't promise any weight change, and we're not selling one. It's worth knowing what each kind of exercise was measured to do.

Blood sugar, from both sides. A JAMA review of trials of 12 weeks or more in people with type 2 diabetes found HbA1c fell by 0.73 points with aerobic training, 0.57 with resistance training and 0.51 with the two combined, all compared with no exercise program [Umpierre, 2011]. Both help. If you take blood sugar medicine, tell your doctor before you start.

Both together: better than either

The strongest case is for doing both, and the studies point the same way:

• Everyday function. In the trial of 160 older adults, the score on a physical performance test rose 21% in the combined group against 14% in the aerobic-only and resistance-only groups [Villareal, 2017]. These were adults 65 and over with obesity on a diet program, so read it as a pattern, not a forecast for you.
• Diabetes and heart disease in women. The Women's Health Study followed 35,754 women, average age 62.6, for about 11 years. Women who did any strength training had a 30% lower rate of type 2 diabetes and 17% lower rate of cardiovascular disease than women who did none, after allowing for their other activity. Women who did both strength and aerobic activity had a lower risk again than women who did aerobic activity only [Shiroma, 2017].
• Long-term health. A review of 16 cohort studies linked muscle-strengthening activity to a 10 to 17% lower risk of dying early, heart disease, cancer and diabetes, with the biggest drop at about 30 to 60 minutes a week. People who did both muscle-strengthening and aerobic activity had a lower risk again [Momma, 2022].

The last two are observational: they watched people rather than assigning exercise, so women who train may differ in other ways too. They show a link, not proof.

Does cardio cancel out strength gains?

No, not at the levels most of us train. You may have read about an "interference effect", where cardio blunts the muscle you build from lifting. A 2022 review pooled 43 studies comparing strength training alone with strength training plus aerobic training. Adding cardio made no meaningful difference to muscle size or maximal strength. It did slow gains in explosive strength (speed and power), more so when both were done in the same session. Age (under or over 40), training status and the type of cardio didn't change the results [Schumann, 2022].

For a beginner doing two 15-minute strength sessions and some walking, the order and timing barely matter. Do what you'll actually keep doing. If you want a rule anyway: on a day you do both, do the strength session first, while you're fresh and your form is clean.

Which first if you only have a little time?

• You already walk most days, but don't lift: add two strength sessions. That's the half of the guidelines you're missing, and 15 minutes each is enough to start.
• You do neither yet: start with two strength sessions and a 10-minute walk on 3 other days. Build the walks toward 150 minutes a week over a couple of months.
• You lift but rarely raise your heart rate: add brisk walks or cycling. Strength doesn't replace cardio's work on your heart and lungs.
• Your knees or back limit you: both still work, with swaps. See the low-impact cardio list below and our guide to exercises for bad knees.

Is 15 minutes of strength really enough? The guidelines set no minimum session length, and two 15-minute full-body sessions make 30 minutes a week, the low end of the 30 to 60 minutes the cohort review linked with the lowest risk. Our guide is a 15-minute workout effective goes through the evidence.

A week with both, in about 2½ hours

This meets both guidelines. The strength days are 15 minutes; the rest is walking you can split up however you like.

That's 30 minutes of strength and 150 minutes of moderate cardio. Brisk means you can talk but not sing. Short on time? Three 10-minute walks count the same as one 30-minute walk under the current guidelines, which dropped the old 10-minute minimum [HHS, 2018]. For more strength days, see how often women over 40 should strength train.

Cardio that's easy on the knees

If your knees complain, keep the cardio and lower the impact:

• Walking on flat ground, in shoes with some cushioning. Start with shorter walks and add 5 minutes a week.
• Cycling, outdoors or on a stationary bike. Set the seat high enough that your knee is only slightly bent at the bottom of the stroke.
• Swimming or water walking. The water carries part of your weight.
• Marching in place or step-touches in the living room, for a rainy day.

Leave out jumping, running downhill and deep lunges until your knees are happy. Strength work helps here too: stronger thighs and hips take load off the knee. Our guides on knee-friendly leg exercises and squat alternatives for bad knees have the swaps. If you also leak a little when you jump, cough or lift, a few weeks of pelvic floor work for leaking when jumping can sit alongside this.

Start today: 15 minutes of strength

Four moves cover legs, hips, push and pull. Do one set of each in turn, then go round again: two rounds in your first week, three once that feels fine.

1. Warm-up, 2 minutes. March in place, 10 arm circles each way, 10 slow half-squats.
2. Sit-to-stand from a chair, 8 to 12 reps. Knee swap: a higher seat, or a glute bridge instead.
3. Counter push-up, 8 to 12 reps. Hands on the kitchen counter, body straight. Wrist swap: the wall.
4. One-arm row, 8 to 12 each arm. A dumbbell or a full water bottle, one hand on a chair. Back swap: a band on a door handle, standing tall.
5. Glute bridge, 10 to 12 reps. Feet flat, lift your hips until knees, hips and shoulders line up.
6. Balance, 1 minute. Heel to toe at the counter, 20 to 30 seconds each way.

Then a 10-minute walk, and you've done both halves today. Write down your reps; next time, add one or two. The beginner plan for women over 40 builds this into 8 weeks.

If you'd rather have it all laid out, our free 2-minute home strength quiz asks about your goal, your knees and back and the minutes you have, and builds a 12-week plan of 15-minute strength sessions with the swaps already picked. You can also read how our home strength plan for women over 40 works and what it costs first.

What the research doesn't promise

• Weight loss. Some pages promise that one kind of exercise "burns belly fat". The trials above measured averages over months. We don't promise any number on the scale.
• Hormones and menopause symptoms. None of the studies here measured hot flashes or hormone levels, and we make no claims about them. Ask your doctor.
• Your exact result. Starting point, sleep, food, health and how often you train all change it. Your own log is the real measure.

When to check with a doctor first

Talk to your doctor or a physical therapist before you start if you have a heart or lung condition, high blood pressure that isn't controlled, osteoporosis or a past fracture, a joint replacement or recent surgery, or you take medicine for blood sugar or blood pressure. Stop and get checked for chest pain, dizziness, sudden breathlessness, or a joint that swells, locks or gives way.

Questions people ask

Should I do cardio or weights first in the same session?

For a beginner it hardly matters: a review of 43 studies found adding cardio didn't blunt muscle or maximal strength gains. If you like a rule, lift first while you're fresh.

Is walking enough exercise for a woman over 40?

Walking covers the cardio half of the guidelines if it adds up to 150 minutes of brisk walking a week. It doesn't cover the muscle-strengthening half, which asks for 2 days a week working all major muscle groups.

Can strength training count as cardio?

A brisk circuit with short rests raises your heart rate, but the guidelines count the two separately, and in trials resistance training alone did less for fitness and fat mass than aerobic training. Keep some walking, cycling or swimming in your week.

How many days a week should I do each?

Strength on 2 or 3 non-consecutive days, and cardio spread across most days to reach 150 minutes. The week above is one way to fit it.

I'm 55 and have never lifted. Is it too late?

No. The reviews of strength and muscle gains above only included adults 50 and over. Start with the easy versions; our guide on starting strength training at 50 covers the first weeks.

More on starting out: what strength training does for women over 40, how much weight to lift, and all our home strength guides.

Sources: US Department of Health and Human Services, Physical Activity Guidelines for Americans, 2nd edition, executive summary, 2018. Bull F.C. et al., "World Health Organization 2020 guidelines on physical activity and sedentary behaviour", Br J Sports Med, 2020. CDC National Center for Health Statistics, "Physical activity among adults aged 18 and over: United States, 2020", NCHS Data Brief 443. Westcott W.L., "Resistance training is medicine", Curr Sports Med Rep, 2012. Peterson M.D. et al., "Resistance exercise for muscular strength in older adults: a meta-analysis", Ageing Res Rev, 2010. Peterson M.D. et al., "Influence of resistance exercise on lean body mass in aging adults", Med Sci Sports Exerc, 2011. Willis L.H. et al., "Effects of aerobic and/or resistance training on body mass and fat mass in overweight or obese adults", J Appl Physiol, 2012. Watson S.L. et al., "High-intensity resistance and impact training improves bone mineral density and physical function in postmenopausal women with osteopenia and osteoporosis: the LIFTMOR randomized controlled trial", J Bone Miner Res, 2018. Villareal D.T. et al., "Aerobic or resistance exercise, or both, in dieting obese older adults", N Engl J Med, 2017. Umpierre D. et al., "Physical activity advice only or structured exercise training and association with HbA1c levels in type 2 diabetes", JAMA, 2011. Shiroma E.J. et al., "Strength training and the risk of type 2 diabetes and cardiovascular disease", Med Sci Sports Exerc, 2017. Momma H. et al., "Muscle-strengthening activities are associated with lower risk and mortality in major non-communicable diseases", Br J Sports Med, 2022. Schumann M. et al., "Compatibility of concurrent aerobic and strength training for skeletal muscle size and function: an updated systematic review and meta-analysis", Sports Med, 2022.

This guide is general information about exercise, not medical advice. Last checked 2026-11-04.