The Impact of Treadmills on Your Legs

Women running on treadmills working on their legs

By Simon Gould

When we walk or run the legs do most of the work. So when it comes to a treadmill, they’re fantastic for your legs. They get worked out in many different ways which is especially the case when you use the incline. This can make your workout particularly tough but beneficial. Here I’m going to go through exactly what the treadmill does for the legs and some workout routines to go with it.

The leg muscles a treadmill works

The entire legs and buttocks get a workout when we use a treadmill. By our very nature we are very efficient at walking and running. Our muscles have developed perfectly to help us do that. Our biggest muscles can be found in our legs and are crucial to help us move around. I’ll tell you the particular muscles activated depending on what activity we’re doing.

Walking – The front of the thighs help you lift your legs and move forward, these are the quadriceps. The back of the thighs enable you to move your legs back as you stride and are the hamstrings. The buttocks are very strong and help complete the backward movement and are the gluteal muscles. The calves help stretch the ankle and help our speed and are the gastrocnemius.

Those were the primary muscles involved. There are secondary ones too which are the front of the calves which hold our feet up so we can then land on our heels as we walk. The buttocks also give us support so we don’t topple over. As you can see it’s all very clever how our muscles work together in helping us get around. This is all done automatically and with little thought.

Walking on an incline – This is common on a treadmill and is often called power walking. It’s a great way of working out as it helps you enter the aerobic state which greatly enhances your cardiovascular health. The muscles worked are the same as in walking above except more intensely. The calves also get more of a workout too.

Running – Muscles used are as per walking except far more intensely. However, particularly the front and back of the thighs. The front to help lift your leg and propel your stride off the ground and forward. The back to accelerate, generate speed and move your legs backward to form your stride as you run. As we all know, this is far harder than walking.

Running on an incline – I would only do this for maximum of a few minutes per workout if you have to. You don’t find permanent hills in nature and you should run on an incline for 30 minutes on a treadmill. It’s not healthy for your joints especially the knees. If you want to make a run harder then go faster but my advice is to avoid the incline for long periods.

Will the size of our legs change?

Our muscles grow when we exercise and is our body’s way of adapting to the stress we’re putting it under. This is very much the case if you’ve never done much exercising or haven’t for a long time. Your legs are not going to get large like a body builder’s from walking or running. You’d have to do weight training for that to happen. Even then some people don’t develop big muscles.

The shape will change like our buttocks are less likely to sag. Our legs will look more aesthetically pleasing. We tend to lose muscle mass as we get older and exercise is good to help prevent this. It’s advised really for any age. Every time I see my regular doctor he asks if I still exercise and is pleased at what he hears!

Any treadmill exercise will strengthen your legs. You’ll start to find the exercise easier as the weeks go by and that’s why you can walk or run further than you used to. No one can do a marathon without training and it’s the difference in the legs over time that make it possible. It’s quite rewarding when you’ve reached a new milestone.

Slimming effects on the legs

Women tend to get fatty deposits around the upper thighs and buttocks. The size will definitely change with regular exercise and a good diet. You will lose some of the fat and have less cellulite. Exercise is one of the most recommended ways to get rid of cellulite. It’s good because your shape will change totally as your muscles grow and your legs tone.

Although a big bottom seems to be in fashion at the moment, exercise may reduce it’s size. You don’t get slim around the legs and butt because that’s the part of the body you’re exercising, that’s called spot reduction and it’s a myth. You get it due to the weight lost by doing your workouts and this occurs over your whole body. So your face, thighs and waist will all reduce in size.

Unfortunately these slimming effects won’t happen with the odd workout or even once a week. For visible results you need to exercise often and eat a sensible diet. If you have a treadmill at home then you have no excuse to make a change to your lifestyle if that is what’s needed. It is possible though and millions of people take that first step.

You get slim by burning more calories than you take in and treadmill exercise helps enormously. Aerobic exercise will help with weight loss which will result in the toning and shaping of your legs. Make sure not to over eat, avoid too much snacking and late night cravings. One thing to think about are the sugary drinks we have which make us gain weight and aren’t good for us.

How often you should exercise

I’ve seen some people take it to the extreme and exercise very often but you don’t have to do that. The World Health Organization says we should get 75 to 150 minutes of aerobic exercise per week. This means brisk or incline walking and running. I recommend 30 minutes, 3 times per week. This will give your legs a great workout.

A treadmill is so convenient for this. First you have the incline so you can power walk uphill for 30 minutes if you want. Walking on an incline for a long period is ok, don’t run on one. Second you have no one in the way like traffic or other people and the weather is always good at home! So remember the water bottle and get on your treadmill to workout.

2 Treadmill leg workouts

All treadmill workouts involve the legs as I discussed before but I thought I’d include some anyway to inspire you. These will all be 30 minutes and I’ll build you up to that amount in case you’re new or haven’t exercised in a while. Your legs will quickly get stronger and adapt as you do this over the weeks. There’s no need to go fast and you’ll see results soon.

On the following workouts I mention day 1, 2 and 3. This is the 3 times exercise and can be done on any days of the week. You can even do it 3 days in a row if that’s how you can fit in as long as you rest on the other days. The length of time increases every week till you reach 30 minutes and this is possible due to the rest days. Your muscles get stronger on the rest days.

1. Incline walking workout

Set your walking speed for 3 mph which is what nearly anyone can do. But we’ll have a good incline to make it tough. I recommend 4% but if this is too much or too little, feel free to change it for your own requirements. The same goes for the speed. Just make sure it’s a tough workout and drive your legs up the incline with every step.

  • All workouts 3 mph and 4% incline
  • Week 1 – Days 1, 2 and 3 for 10 minutes each
  • Week 2 – Days 1, 2 and 3 for 15 minutes each
  • Week 3 – Days 1, 2 and 3 for 20 minutes each
  • Week 4 – Days 1, 2 and 3 for 25 minutes each
  • Week 5+ – Days 1, 2 and 3 for 30 minutes each
  • Around 260 calories burned every 30 minutes

2. Jogging or running workout

The important aspect of this workout is the speed. To see results you don’t need to go fast at all. As long as you’re lifting your feet you’re running and that’s the important thing. Going fast won’t have you getting results much quicker and you’ll burn yourself out. I’ve built up slower for this one than the walking because running is harder.

  • All workouts 5 mph and 0% or flat incline
  • Week 1 – Days 1, 2 and 3 for 5 minutes each
  • Week 2 – Days 1, 2 and 3 for 10 minutes each
  • Week 3 – Days 1, 2 and 3 for 15 minutes each
  • Week 4 – Days 1, 2 and 3 for 20 minutes each
  • Week 5 – Days 1, 2 and 3 for 25 minutes each
  • Week 6+ – Days 1, 2 and 3 for 30 minutes each
  • Around 350 calories burned every 30 minutes

Workouts summary

If you reach 30 minutes per workout day quicker or slower then that’s ok. You’ll start feeling great when you exercise for that long, I know I do and I do 30 minutes at 5.2 mph. If you want to run and you need to build up slower, I have a walk run treadmill routine that will have you running 30 minutes in 9 weeks. It’s very gradual and is called the couch to 5k.

When you’ll start seeing results

As mentioned before the legs adapt and get stronger very quickly. This is evidenced by the fact that if you run 5 minutes, you’ll be able to do 10 the following week. The shape of your legs and toning should begin in around 2 weeks if you followed a workout above. In 2 weeks you’ll have done 6 workouts and although you start off slowly, you should have started losing weight.

It’s the weight loss that will give you toning and thinner thighs. If you weigh a lot to begin with, the results could be quite dramatic. Remember to think about your diet as well. The better muscle tone will really give your butt an uplift and a more pleasant shape. To get even better results all you have to do is keep working out. It sounds easy and it is if you make the time.


If you have your own treadmill at home then there’s no excuse not to give your legs a great workout. The World Health Organization recommend 2 strength days a week so you could enhance your legs even more. But for toning and shaping then the routines above are the way to go. I’ve noticed a change when I exercise frequently and you will too.

Exercise has many benefits and you’ll get these as a positive side effect of your workouts. If you don’t have your own treadmill then there are gyms everywhere these days. Some are very reasonable in price and may be worth using. I’ve used a gym before for treadmill workouts and some of them even have a spa. Whatever you choose to do you’ll notice your legs change positively with regular exercise.

Thinking of buying a treadmill? Here’s my favorite, I always recommend it when asked.

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