Walking vs strength training for weight loss: which is better?

Key takeaways - In an 8-month trial, aerobic exercise reduced body weight and fat more than strength training, while strength training added lean mass. - In older adults who were dieting, combining aerobic and strength exercise improved physical function the most and limited muscle loss. - More daily steps are linked with lower risk of early death, with benefits levelling off at around 6,000 to 10,000 steps depending on age. - The WHO recommends 150 to 300 minutes of moderate activity a week plus strength exercise on at least two days. Most people do best with both.

If you are trying to lose weight, you have probably wondered where to spend your limited time: walking, cardio or lifting weights. The honest answer is that each does a different job, and the best plan for most people uses both.

This guide compares walking and strength training using the main trials, explains what each does for weight, fat and muscle, and gives you a realistic weekly plan you can adapt to your fitness and time.

What each type of exercise does

Walking, cycling, swimming and jogging are aerobic exercise: they keep your heart rate up for a sustained period. Strength training, also called resistance training, works muscles against a load: weights, machines, resistance bands or your own body weight.

	Walking and aerobic exercise	Strength training
Energy used per session	Higher for the same time	Lower, but adds up over the week
Effect on body weight	Modest reduction	Little change on the scale
Effect on fat mass	Reduces fat	Small reduction
Effect on muscle	Little or none	Maintains or builds muscle
Heart and lung fitness	Strong improvement	Some improvement
Bone, strength and balance	Some benefit	Strong benefit
Ease of starting	Very easy, no equipment	Needs some instruction to start safely

Neither column is "better". They answer different questions. Aerobic exercise helps you use more energy and improves heart health. Strength training protects the muscle that keeps you strong, mobile and metabolically healthy while you lose weight.

What the trials found

Aerobic vs resistance training

The clearest head-to-head comparison is a trial by Willis and colleagues. Sedentary adults with overweight or obesity were randomly assigned to aerobic training, resistance training or both for 8 months. They were not asked to diet.

The aerobic and combined groups lost more body weight and fat mass than the resistance group. The resistance and combined groups gained lean mass, which the aerobic group did not. The combined group got both benefits, but it also needed about twice the training time.

The authors concluded that if the aim is to reduce weight and fat, aerobic exercise uses time most efficiently, while resistance training is needed to increase lean mass. The changes in weight were modest in all groups, which is typical when exercise is used without changes to eating.

Combining both while dieting

Most people trying to lose weight change what they eat as well. A trial in the NEJM by Villareal and colleagues tested this in 160 adults aged 65 and over living with obesity. All three exercise groups followed a weight-loss diet and did aerobic exercise, resistance exercise or both for 6 months.

Weight fell by around 9% on average in each exercise group, so the type of exercise did not change how much weight was lost. What it changed was the quality of that loss:

• Physical function improved most in the combined group.
• Lean mass and hip bone density fell less in the groups that included resistance training than in the aerobic-only group.
• Aerobic fitness improved most in the groups that included aerobic exercise.

These results come from older adults, who lose muscle and bone more easily, but the principle applies widely: when you lose weight, strength training helps make sure more of it comes from fat. Our guide on protecting muscle during weight loss goes into this in detail.

How many steps do you need?

Step counts are a simple way to track walking. A meta-analysis of 15 cohorts including about 47,000 adults found that more daily steps were linked with a progressively lower risk of death from any cause. The benefit levelled off at around 6,000 to 8,000 steps a day for adults aged 60 and over, and 8,000 to 10,000 steps a day for younger adults.

Two caveats are important. This study looked at long-term health, not weight loss, and it was observational, so it shows an association rather than proof. Still, it suggests you do not need to hit an exact target for walking to be worthwhile. If you currently walk 3,000 steps a day, getting to 5,000 or 6,000 is already a meaningful step.

As a rough guide, 30 minutes of brisk walking uses around 120 to 180 kcal for someone weighing 70 to 90 kg, more if you weigh more or walk uphill. The TDEE calculator can estimate how your activity level changes your daily energy needs, though any figure is only a starting point.

What the guidelines recommend

The WHO guidelines on physical activity recommend that adults:

• Do 150 to 300 minutes of moderate aerobic activity a week (such as brisk walking), or 75 to 150 minutes of vigorous activity, or a mix.
• Do muscle-strengthening activity on two or more days a week, working the major muscle groups.
• Reduce time spent sitting, replacing it with any activity.
• For adults aged 65 and over, add activities that challenge balance and strength on three or more days a week to help prevent falls.

The WHO also stresses that some activity is better than none. If 150 minutes sounds a long way off, start with what you can do and build up.

A combined weekly plan

This plan suits most adults starting from low activity. Adjust it to your fitness, joints and timetable, and check with a doctor first if you have heart disease, chest pain on exertion, uncontrolled blood pressure or another condition that limits exercise.

Day	Activity	Time
Monday	Strength session (full body)	30-40 min
Tuesday	Brisk walk	30 min
Wednesday	Brisk walk, or cycling or swimming	30 min
Thursday	Strength session (full body)	30-40 min
Friday	Brisk walk	30 min
Saturday	Longer walk, hike or active outing	60 min
Sunday	Rest or gentle stretching	As you like

This gives about 150 minutes of aerobic activity and two strength sessions, which meets the minimum WHO recommendation. Longer walks or an extra session take you further into the 150 to 300 minute range.

Building the strength sessions

• Choose 5 to 6 exercises covering legs, hips, back, chest and arms: squats or sit-to-stand from a chair, lunges or step-ups, a row with a band or dumbbell, wall or knee press-ups, a hip bridge and a plank.
• Do 2 to 3 sets of 8 to 12 repetitions. The last two reps of each set should feel hard but controlled.
• Progress slowly. Add a rep, a set or a little weight every week or two.
• Learn good form first. A session or two with a qualified trainer, or a reputable beginner programme, makes a big difference.

Make walking part of daily life

• Walk to the shops, get off the bus a stop early or take a 10-minute walk after meals.
• Use a phone or watch to track your daily average and raise it gradually, about 500 to 1,000 steps a week.
• Walking with someone else, or with a podcast, makes it easier to keep going. A short walk is also a useful way to reset when stress builds, as our article on emotional eating and stress explains.

Support it with protein

Strength training works best with enough protein. A meta-analysis by Morton and colleagues found that extra protein increased gains in muscle from resistance training, with little further benefit above about 1.6 g per kilo of body weight a day. If you have kidney disease, check your protein target with your doctor.

What exercise can and cannot do for weight

Exercise on its own usually leads to modest weight loss, because the body partly compensates by increasing appetite, and the energy used in a session is easy to replace with food. That does not make it less important. Regular activity is one of the habits most strongly linked with keeping weight off, and it improves heart health, blood sugar, mood, sleep and strength whatever the scale says.

If your weight has stalled even though you are active, that is common. Our guide to weight-loss plateaus covers what to check.

How Docalo can help

Docalo is an online medical service focused only on weight loss. Your €49/month membership covers a doctor consultation, a personal plan and follow-up with the medical team, including an activity plan that fits your health, fitness and timetable.

A licensed doctor reviews your health questionnaire and decides whether treatment is appropriate for you. If they prescribe medication, it is paid separately at the pharmacy. If you want help building activity into a realistic plan, you can start your consultation.