What happens if you don't warm up before a run?

Woman running wearing road shoes
(Image credit: Getty)

Running is simple to do and very accessible to so many people, but there are also many 'extras' to think about. We are all told to ensure we do a warm up before a run, then a cool down after a run, as well as taking proper rest and recovery, plus adding in regular strength sessions

It’s no wonder then that runners ask what happens if you don't warm up before a run? We spoke to the experts about whether runners really need to do a warm up before a run.

Keoghan Bellew, a personal trainer at Fitness Superstore,  says that it depends on what you have being doing before you start to run that is important. 

He says: “If you have been moving about a lot in the day, perhaps walking, rather than sitting at a desk, it might be that your muscles are already slightly warmed up. However, the chances are it will improve your run if you do a warm up first.”

Person sprinting on pavement

Experts recommend a warm up to avoid injury while running (Image credit: Getty)

Warm up first to avoid injury 

A key issue of running without a warm up first is the potential for injury. Jack Hinks, head of sports therapy at CoreClinics.co.uk, says: “If you start to run – especially at a faster pace – when your muscles aren't warmed up, you increase your risk of injury, such as muscle tears and pulls. 

“Warming up takes your muscles from a shortened and stiff resting state to a more pliable and flexible state where they can better withstand the strain of exercise.”

Hinks also makes the point that even if you are a runner who doesn’t end up injured because they don’t warm up, the chances are the run will not be as flowing or comfortable. 

“Although you won't necessarily injure yourself if you don't warm up, it's still likely that your run will be less successful because your muscles will take a while before they are at peak performance," he says.

“In the meantime, you're likely to find that your stride is shorter and less fluid, while your power output is reduced and, therefore, your pace is slower and you'll get tired more quickly.” 

Abbas Kanani, a pharmacist at Chemist Click, says that a warm up is also key for the body's circulatory and respiratory systems. He explains: “It’s important to prepare the body's circulatory and respiratory systems for high intensity movement and to activate the muscles and nerves that assist with flexibility and movement while running.

“An increase in blood flow is particularly important. The movement from warm up exercises boosts blood flow, which causes blood vessels to dilate, putting less stress on the heart.

“It also improves muscle elasticity which reduces the risk of serious acute injury, such as rips, tears and twists. 

“In addition, a good supply of oxygen to the blood aids waste products, which are produced during exercise, to be removed so you're less likely to feel pain associated with high intensity activity.”

Woman hill running

A jog is a great way to warm up for a run (Image credit: Getty)

Do I need to warm up before a run? Yes, if you want to enjoy it

Bellew says that a warm up before a run is likely to lead to a happier outing. "Giving your muscles the opportunity to warm up and become more flexible not only prevents injury, but also makes running more enjoyable and allows you to perform to your best much more easily.”

Carrying out a warmup also has benefits for your cardiovascular system. “Warming up helps to gradually increase your heart rate and breathing to the level that your body will need to perform in your workout," says Bellew.

“Just like preparing your muscles, preparing your breathing is crucial because if you begin exercising at a strenuous level straight away, you will place unnecessary stress on both your lungs and heart.”

What exercises to do to warm-up before a run

Bellew says that to maximize your running warm-up, you should include some dynamic stretching before a run. “Doing movements like these that are based on the movements you’ll need for running prepares your body for what’s ahead," he says. "This should allow you to enjoy the running session without strain.” 

Keoghan says that a good protocol for a warm up is a RAMP:

  • Raise your heart rate
  • Activate your muscles
  • Mobilize your joints
  • Potentiate for the chosen exercise (that is, slowly increasing the intensity from walk to jog to run)

Woman stretching against a railing

Many runners ask whether they need to warm up before a run (Image credit: Getty)

Try a jog before a run

Kanani says that a slower pre-run jog for five to 10 minutes is a good warm up. “By starting slowly and building up the pace, you’ll help to raise your body temperature causing oxygen to become more obtainable to muscles," he explains. This helps with tightening and relaxation of muscles facilitating a more comfortable run.

“Further to this, it helps with prevention of overheating aiding the body to cool off efficiently," he adds.

What happens if you don't warm up before a run?

Some runners will tell you that they never do a warm up and they are always fine, but many people find that a warm up is crucial for avoiding injury and for improving their running efficiency, pace and ability. 

We are all different, but in answer to the question, do I really need to warm up before a run? Our experts all say: “Yes.”

Fiona Russell
Outdoor writer

Fiona Russell is a widely published adventure journalist and blogger, better known as Fiona Outdoors. She is based in Scotland and is an all-round outdoors enthusiast with favorite activities including trail running, mountain walking, mountain biking, road cycling, triathlon and skiing (both downhill and backcountry). Aside from her own adventures, Fiona's biggest aim is to inspire others to enjoy getting outside and exploring, especially through her writing. She is also rarely seen without a running skort! Find out more at Fiona Outdoors.