In: Training

Why runners should lift weights

Whether you run to race, manage your weight or look after your health, you might be surprised to learn that weight training can not only build muscle and strength, but can improve running performance, aid fat loss, reduce the incidence of pain and injury and improve the general health of runners (and most other endurance athletes) of any age and ability.

Running shoe


Runners can run faster by losing weight (20 seconds per mile faster for every 10lbs of weight lost), but there’s only so much weight they can lose.  Let’s look at three areas where weight training can directly affect running performance.


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 for you and your technique is great, then you may think you’ve hit your best possible running performance.  Cue weight training.  You’ll get improved leg strength and improved ability to utilise oxygen and transport it to the muscles.  As they are 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 so you can run faster and further.  Fast twitch muscle fibres are only trained through weight training and they generally respond best with heavier weights and fewer repetitions than you would expect for endurance benefits.


Runners can develop a stoop where their shoulders roll forwards and their body weight shifts, 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 can’t hold good form any longer without real conscious effort.  Having a stronger core means you are less likely to stoop, suffer from lower back pain and your posture will improve for running and life generally.

Training your core through planks or endless sit-ups is not very effective and will not improve running performance materially.  Hitting the squat rack, getting to love deadlifts or working at any other compound multi-joint exercise in the weight room will work your core more in tune 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 waist band and may be weak if your hips are rotated forward and your bum is pushed back.  Try lying on floor on your back with your feet up and knees bent 90 degrees.  Keeping your head and shoulders on the floor and your hands out of the way, try to raise your hips off the floor.  Your hips don’t need to move far, but if they don’t move at all, you could benefit from strengthening your lower abdominal muscles.

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.  And if you do gain too much, just reduce the amount of time in the gym.

Fat loss

Done properly, weight training supports fat loss as it forces your muscles to grow, and bigger muscles burn more calories, leading to a decrease in the fat stores that you lug around with you when you run. In tests, cyclists who weight trained regularly decreased their body fat percentage by significantly more than those who only trained for endurance.

In addition, long term fat loss becomes more sustainable when muscle mass increases.  It’s easier to eat a normalised (rather than restricted) diet when you have the metabolic advantages of greater muscle mass under your belt.

Running for fat loss

Overweight people with little or no exercise routine will lose fat by running, but as running trains our bodies to become efficient at how it uses energy, there comes a point when this is no longer the case.  It’s better for your body to be inefficient at burning energy – that way, you burn more energy performing the same amount of exercise.

Replace some of your runs with high intensity sprint sessions – you can burn up to nine times more calories per minute of exercise this way.

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 as we pass 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.


Non-steroidal anti-inflammatory drugs (NSAIDs) such as Ibuprofen mask pain but do not heal. Whilst occasional use is fine for most people, regular use is neither normal nor without risks, including:

  • Cartilage degeneration
  • Bone destruction
  • Gut issues (constipation, diarrhoea, stomach bleeding, ulceration)
  • Kidney failure
  • Liver failure
  • Cardiovascular risks (heart failure, heart attack)
  • Stroke

Risks increase the longer that NSAIDs are used, but can occur in the first weeks of use, whether or not you have any heart disease factors present.


Activity levels are related to health, but note that regular long runs (more than an hour) take their toll.  Weight training should form part of your tool kit to counteract negative effects and improve overall health.

Blood pooling

Without weight training, an endurance athlete 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 necessary to fuel high activity levels, however the disproportionate size of the chamber can lead to blood pooling in the extremities if the heart and vascular system are not strong enough to pump that much blood.  One symptom is dizziness when standing up.

Weight training with sufficient intensity will strength the walls of the heart, increasing its ability to circulate blood throughout the whole body more effectively.

Better insulin health

Insulin controls 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 another hormone called irisin that improves insulin management and helps ensures cells remain highly sensitive to insulin (a good thing, particularly for runners who regularly carb load before long runs).

Antioxidant improvements

Any exercise that increases your breathing rate 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 my top tips for integrating weight training into a runner’s training programme:

  • Even recreational runners need an off-season.  Give your body a break from running and use the time to create a stronger base for the next season in the gym.  I suggest at least three months where you focus on weight training and reduce running volume significantly.
  • Training programmes should be progressive and support your overall objectives.  That means working through muscle hypertrophy, strength and power phases with each phase having different exercises, sets, repetitions and intensities.
  • 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 to your running season, you should continue weight training, but lower the intensity of leg training and focus more on upper body.
  • If you’re new to weight training, get a personal trainer to make sure you train appropriate and safely.

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

Are you ready to thrive?