Why runners should lift weights

Runners of all levels limit their performance by avoiding the gym
Ian Locke
Ian Locke
Nov 22, 2020

Whether you run to race, manage your weight or look after your health, did you know that weight training can improve running performance, aid fat loss, reduce the incidence of pain and injury and improve the general health of runners, regardless of age and ability?


We know that runners can run faster by losing weight – 20 seconds per mile faster for every 10lbs lost – but there’s only so much weight people can lose. Let’s look at three areas where weight training can directly affect running performance without needing to slim down.


Runners improve their running with weights

Runners run faster and harder with weight training

Simply running more frequently will only help you run faster up to a point. If your nutrition is spot on, your physiology is working perfectly and your technique is great, then you may think you’ve hit your best possible running performance.

Cue weight training.

Done correctly, you’ll increase leg strength, your ability to utilise oxygen, and will be able to transport oxygen and other nutrients to your muscles more effectively – vitally important for endurance sports. Being fuelled for longer, your muscles will tire less quickly. You’ll also get better coordination and neural drive, making your movements more efficient (5% more efficient in studies).

Muscles are made up of slow-twitch fibres (endurance), fast-twitch fibres (power) and other muscle fibres which can behave like either of the other types. Whilst endurance training relies predominantly on slow-twitch fibres, fast-twitch fibres will give you the power to kick off the ground harder for longer.

It’s these fast-twitch muscle fibres which help you run faster and further. They are best trained through weight training with heavy weights and few repetitions.


Runners can develop a stoop where their shoulders roll forwards and their body weight shifts forwards, placing unnecessary stress on the spine. You see it happen to runners part way through a long race when their postural muscles tire and they struggle to hold good form.

It’s possible to prevent (or at least delay) this by strengthening your core, reducing your risk of suffering lower back pain. Before you start doing planks or endless sit-ups, know that those are not very effective and will not materially improve your running performance.

Hitting the squat rack, learning to love deadlifts or working at any other compound multi-joint exercise in the weight room will work your core more in line with what it is designed for – providing stability when moving and lifting.

And don’t forget your upper body. Weighted rowing exercises are great at retracting the shoulders and developing strength in upper back muscles, making it easier to maintain form and delaying any unconscious stooping.

Muscle growth and strength

Getting stronger leads to improved performance for all distances. In studies, running economy increased by 5-10%, time at maximal speed rose 20% and speed/time trial performance improved 5-8% through weight training. The improvements come from greater engagement of fast-twitch muscles, better coordination between brain and muscles and greater neural drive.

Weak lower abdominal muscles can negatively impact running form, leading to back pain. These are the muscles below your waistband and may be weak if your hips are rotated forward and your bum is pushed back. Check out our training video aimed at correcting this anterior pelvic tilt.  It’s designed from our own experience of removing crippling back pain.

If you’re concerned about putting on too much muscle, don’t be. It’s actually quite hard for endurance athletes to gain large amounts of muscle given that endurance training breaks down muscle for fuel.

Fat loss

Overweight people with little or no exercise routine will lose fat by running. However, as running encourages our bodies to become efficient at how they use energy, this only works to a point.

If fat loss is your goal, it’s better for your body to be inefficient at burning energy – you want to burn more energy performing the same amount of exercise.

Weight training supports long-term fat loss as it forces your muscles to grow and burn more calories. In tests, cyclists who weight trained regularly decreased their body fat percentage by significantly more than those who only trained for endurance.

Pain or injury prevention

Runners are prone to injury. Then there are all the aches, pains and niggles they just live with. Weight training has its own risks, aches and pains, but a well-constructed personalised training programme delivered by someone who knows the importance of good form and working at the right intensity can mitigate many of those risks, as well as help to eliminate regular aches and pains, help correct posture and improve movement patterns.

For example:

  • Strengthening your calves may reduce the incidence of shin splints.
  • Single leg work helps equalise muscles on each side of the body, making strides more symmetrical and equally powerful from both legs.
  • Strengthening the posterior chain (back of the body from the ankle to the neck) and stretching the front of the body is likely to be beneficial to runners suffering from tight hip flexors and weak glutes and core.

Running-specific studies on the benefit of resistance training for injury prevention are hard to find, but a meta study published in the BMJ in 2013 looked at sports generally and concluded that “strength training reduced sports injuries to less than one third and overuse injuries could be almost halved”.

Age is also a factor in injury risk, particularly as bone mineral density naturally decreases after 35 years, increasing the risk of fractures. The good news is that weight training has been shown to help reverse the decline in bone mineral density due to the increased stress placed on our skeletal structure. Maximum benefits are achieved by moving joints through full ranges of motion under resistance (which will also help defer age-related mobility issues and reduce the incidence of osteoarthritis).

If you don’t think pain or injury prevention is important for you, ask yourself the following questions:

  • How often do you take ibuprofen or other anti-inflammatory drugs to reduce pain?
  • How often do you decide to miss a training run due to aches and pains?
  • How much do you spend on corrective physiotherapy?

I’m not claiming that weight training will avoid all of this, but investing time in the gym should save you money and keep you running.


Being active is important for our health, but regular long runs (more than an hour) will take their toll. Using some of your exercise minutes weight training each week will help counteract the negative effects of running and improve overall your health.

Blood pooling

Endurance athletes can develop a large left ventricle in their heart relative to the thickness of their heart muscle. The larger chamber is necessary to deliver the high volume of oxygenated blood needed to fuel activity levels. However, the disproportionate size of the chamber can lead to blood pooling in the extremities.

A minor symptom is dizziness when standing up as the heart and vascular system are not strong enough to pump that much blood continuously.

The heart is a muscle and responds to weight training. Strengthening the walls of the heart and increasing its ability to circulate blood throughout the whole body more effectively will help to prevent blood pooling.

Better insulin health

Insulin helps control the amount of glucose in our bloodstream, but if we regularly produce a lot of insulin (e.g. through eating excessive sugary foods), we can become resistant to it and this can lead to type 2 diabetes.

Weight training has been shown to increase the release of a hormone called irisin that improves insulin management and helps ensure cells remain highly sensitive to insulin (a good thing for runners who regularly carb load before long runs).

Antioxidant improvements

Any exercise that increases your breathing rate also increases the number of free radicals in your body. Free radicals contribute to muscle fatigue and we rely on antioxidants (including vitamins A, C & E) to reduce them. Weight training has been shown to increase the number of antioxidants in the body, though the better trained you are, the better your body becomes at dealing with free radicals.

Better reproductive health

All those free radicals from endurance exercise can mess with your sex hormones, leading to poor reproductive health and reduced fertility. Weight training helps as it reduces the impact of free radicals and improves hormone balance.

Weight training for runners

Here are Thrive’s top tips for integrating weight training into a runner’s training programme:

  • Even recreational runners need an off-season. Give your body a 3-month break from running and use the time to create a stronger base for the next season in the gym.
  • Training programmes should be progressive and support your overall objectives. That means working through muscle growth, strength and power phases.
  • Focus on large, compound, multi-joint exercises (squats, deadlifts, presses, rows, pull-ups, jumping, etc.), mixing up one- and two-legged exercises.
  • Don’t forget about your upper body as this is important for posture as well as powering through the arms.
  • Once back in your running season, continue weight training at a lower intensity, focussing more on upper body.
  • If you’re new to weight training, get a personal trainer to make sure you train appropriately and safely.

Have we convinced you?

Weight training not only builds muscle, strength and power for running, but it can improve all aspects of your life: mobility, health, depression, sleep, body confidence, body composition, sports performance, diabetes, effects of ageing, and posture.

It’ll also help you shovel snow, rescue kittens from trees and look good naked.

Are you ready to thrive?

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