The number of people running on a regular basis has risen by more than a third since 2005, Sport England says. Who are they?
Every week close to two million people are spending at least 30 minutes running to keep fit. The numbers are up 75,000 in the past six months alone, Sport England says.
So who are the people pulling on their trainers and going for a jog?
The classic club runner
Catherine Jones, from Altrincham, did no sport at school and started running at 25 - 12 years ago. She uses club runs to motivate her to train and covers 16 miles a week. Personal bests - 5km in 22.22, 10km in 45.32, half-marathon in 1hr 42mins, with an aim to beat this next March.
Running is my "me time" and I couldn't be without it. I work full-time and have a one-year-old and a two-year-old, so running is a way I get a few minutes' peace and clear my head.
What started as a bit of jogging to keep fit has now become an essential part of my life and I even ran 150 miles across the Atacama Desert [in South America] with my husband for our honeymoon.
I ran through both my pregnancies and am currently trying to get back to fitness properly after having children. The support from my fellow club members has been fantastic and there are plenty of women there setting great examples of how it's possible to include running in family life.
Quite simply, I wouldn't be able to motivate myself to train as hard if I ran on my own - it's great having other people to push you along. At this stage, just getting out of the house to the start line of a race feels like an achievement but my times are really improving again.
I've actually broken both my 5km and 10km personal bests since having kids, so perhaps it's the case that sleep deprivation gives you more endurance.
The weight loss runner
Mathew Warr, from Yeovil, started 11 months ago. Runs three to five times a week and covers 20 to 30 miles, including 10 on a Sunday. Training runs on an empty stomach, with a meal afterwards. Personal best - 5km in 25.32, 10km in 56.03 and half marathon in 1.59.52.
For me, running started as a way to shift some pounds. I've not got your classic "runner's physique". I'm just a normal bloke who likes a beer and a takeaway and, when I started running, I used to be really self conscious.
But I soon realised that it doesn't matter how I look, or how fast I run - I'm still quicker than those on their backsides, in their cars, or on the sofa.
My competitive nature started shining through and I soon wanted to beat my times. Then I set my sights on distances and week by week, month by month, the sense of accomplishment and personal satisfaction simply drove me to want to run further and faster. Over a period of months running went from chore, to challenge, to pleasure, to passion.
The things I love about running are that it's free - all you need are a pair of shorts, T-shirt and trainers - you can run anywhere and everywhere, it is totally inclusive and is a great way to spend time with friends and family.
My first half marathon was run for Macmillan Cancer Support, who helped my brother through his Hodgkin's Lymphoma treatment - I raised over £500.
Now I don't fundraise as it's not as much of a challenge for me anymore and I don't think I have the right to ask people for money to do something I already enjoy.
Rory Coleman, from Cardiff, started running 20 years ago. Runs an average of 60 miles a week - including one or two marathons - and covered 196 miles one week in 2013. Prepares with "good wholesome unprocessed food". Personal best - marathon in 3hrs 24 mins.
I didn't set out to run hundreds of marathons, set nine Guinness World Records and run the Marathon des Sables [a 150-mile race through the Sahara] 10 times.
I just went for a very short run on 5 January 1994, to help me lose weight when I gave up smoking and drinking. It proved to be an amazing life transformation and, as I became fitter and lighter, my training runs got longer and I wondered just how far I could run.
The 1995 London Marathon provided a suitable goal as it had always been something I'd been in awe of, but never fit enough to contemplate running.
I enjoyed it so much I ran another marathon the following weekend and I've been running marathons most weekends ever since.
Long-distance running gives me an immense feeling of satisfaction and I now make my living teaching other people of all abilities how to run and achieve their dreams.
It's such a positive thing to do and I've been to some amazing places and met incredible people over the years. My dream now is to complete my 1000th marathon and keep running for as long as I can.
The mood-boosting runner
Laura Williams, from Birmingham, runs up to three miles - three or four times a week. Prepares with a banana, or porridge. Personal best - "too early to say, but training for next year's Birmingham half marathon".
Rewind to Christmas 2011. I stood on my sister's scales to see a staggering 15st 5lb (97.5kg).
I was bloated and desperately depressed, in constant physical pain and could barely walk. I saw endless doctors and was finally diagnosed with fibromyalgia. A few years earlier I had been diagnosed with rapid cycling bipolar disorder, so I was already on a lot of medication. Combine the two and, at times, I was like a zombie.
The following September work as an English teacher head of department became really stressful and I was doing 15 hour days, eating junk food, suffering from insomnia and hadn't been to the gym in weeks. My weight went up to a nightmare 14st 8lb (92.5kg).
By the end of September I decided to step down from my job, as the stress was having a huge impact upon my mental health. With an improvement in my state of mind I returned to the gym.
I still haven't lost any weight, but I have started to feel a little fitter and much more positive. I am now running outside and can just about do 20 minutes solid before I have to "walk/run".
I am at the very start of my running journey and I feel completely out of my depth. So far it has been pretty painful and I constantly have to keep bribing myself to actually get out there and do it, but when I do, bizarrely, I love it.
The awareness-raising runner
Mark Maddox, from Liverpool, has been running all his life. After being diagnosed with motor neurone disease, he has run marathons to raise both money and awareness of the condition. He runs for the Motor Neurone Disease Association. Personal best - marathon in 6hrs 20mins.
I've run and generally kept fit all my life. I played football at semi-pro level, so that was essential. Since being diagnosed with motor neurone disease (MND) I've run two marathons - the first person to do so with MND.
I plan to run a third and fourth in the new year - London in April and Liverpool in May.
I did my first one in Liverpool and got such a great reaction, and such a lot of attention for my condition, that I decided to run London because I thought that would get even more.
Around 95% of people with MND can't do what I do, so I feel obliged to do it and raise as much awareness as possible. Hopefully a billionaire will see what I am doing and give us some money to find a cure.
I still get a kick out of putting on my headphones and going out for a run - twice a week. I love my music and running, though it is more like a walk now. It allows me to lose myself and forget about the fact I have this deadly condition. It's a massive part of how I cope with it.
The barefoot runner
Ken Bob Saxton, from Orange County California, runs between 10 and 20 miles each week and walks another 20 to 30 miles, all barefoot. He's been running "pretty much since [he] could walk". Personal best - marathon in 3hrs 19mins.
I don't have the addictive personality to run through pain, run every day, or heedlessly pound my feet into the ground. I'm not tough, but challenging terrain under my bare soles serve as a stimulating reminder to figure out how to run and walk more gently.
This "dance" translates into an ever-improving technique which is focused on propelling my body forward, with less wasted up and down pounding.
I love running alone for the time to reflect. I love running with others for the thoughtful conversations and mindless humour shared.
Running, especially barefoot, reminds me that I am natural (especially in the city), centres my mind and body, and when done gently, for reasonable distances, refreshes me.
My feet take me most anywhere I want to go, even if only for a walk or run. Running and walking are simple forms of transportation, yet also sophisticated and elegant.
The early morning runner
Gary Bradwell, from Elland, West Yorkshire, has been running for 20 years (since he was 13). Runs three times a week, averaging 30 miles, including a half marathon. Prepares with porridge and honey, crumpets and jam. Personal bests - 5km in 19.12, half marathon in 1hr 37mins.
Running was once a matter of routine and necessity while serving in the Royal Marines. But I continued it into civilian life, where I have found it to be one of the very few moments when I find time for myself and am able to think most clearly.
As an early morning runner it's where I get to witness nature at its most entertaining and get to experience and enjoy the diversity of the Pennines where I live and the city where I work.
More recently it has become a medium in which I have been able to raise several thousand pounds for charity.
That all contributed to added satisfaction and focus in life, beyond just work and family.
In 2012 I was able to raise £900 for Martins House Children's Hospice and, in 2013, £3,000 for the Make a Wish Foundation. In December I'm running 40 miles for a terminally ill boy and have currently raised £1,500.
The retired professional
Mara Yamauchi, from London, is a former professional marathon runner. She now runs six days a week, covering 60 miles, and chooses "healthy, nutritious" Japanese food. Personal bests - 10km in 31.43, half marathon in 68.29, marathon in 2.23.12 (second fastest British woman of all time).
When I was 11 years old I was mesmerised by the Los Angeles Olympics and decided I was going to be an Olympian.
I had no idea what, where, or how I was going to do it, but fast forward 24 years and I was lining up in the women's marathon at the 2008 Beijing Olympics.
A competitive streak, and the sheer joy of running freely outside in nature is what motivated me to train and compete at the highest level.
After running for TeamGB at the historic 2012 London Olympics, I decided it was time to retire from elite competition, so now I run for fun and to stay healthy, which I just love - all the fun with no pressure.
I often find myself having to subdue my competitiveness, or my older body won't like it.
Humans are evolved to run long distances - to me it's the most natural thing in the world to do.
The fell runner
Roger Ashby, 70, from Hale in Greater Manchester, runs one to three times a week - depending on whether he is racing - covering nine to 25 miles. Powered by a "solid breakfast" and high energy food. Personal best - "not relevant", as it depends on weather and underfoot conditions.
I've been a competitive runner most of my life, running and racing variously over distances from 400m track races to road marathons and ultra trail runs.
I graduated to serious fell running at 61 in 2004, when I joined the Fell Runners Association (FRA) and have been doing it ever since. Increased traffic had stifled the appeal of running on the roads - and I was getting slower.
Nowadays, I'm an active member of Pennine Fell Runners, training for and taking part in races throughout the year.
These range from English Championship races at venues such as the Lakes and further afield, to club handicaps locally - with the odd mountain marathon event thrown in for variety.
Why do I still do it? I still enjoy a challenge and both the terrain and the weather can be significant factors. I can still do it, dodgy knees notwithstanding.
Fell runners are an independent-minded and welcoming bunch. It's a comparatively small world and you soon get to know your rivals who quickly become friends.
You'll encounter some superb and relatively remote hill country scenery that is entirely different to road running.
The lapsed runner
Laura Street, from London, ran for two years, covering up to 10 miles a week. Ran home from work, along canals and in her local park. Personal best: 10km in 59mins.
After years of not doing regular exercise, I started running after a break-up with a long-term boyfriend - just to feel a bit healthier and happier. I'd never fancied the idea of the gym - lycra scared me - and thought running would be an inexpensive way of getting fit and getting some fresh air.
At the time I was working long hours, so just being outside a few times a week was a positive change. I didn't run fast but started being able to go longer distances - running the five miles home from work (without stopping) was a triumph, and I loved discovering new parts of London through running on a weekend.
Last spring, a group of us from work entered a 10km, to show support for a colleague and his wife, through raising money for a cancer charity.
Training together before the race and the feeling of finishing (along with going to the pub afterwards) was a brilliant experience and we raised lots of money for a great cause.
Despite the camaraderie on the day, I found the race really tough and definitely didn't enjoy the feeling of being overtaken at the start by the majority of other competitors.
After that, I think I felt that I'd reached the pinnacle of my running career, and I'm ashamed to admit that my running shoes have been in retirement ever since.
Maybe when the nights start getting longer I'll dig them out from the back of the cupboard.
Additional reporting by Duncan Walker and Alex Hudson.