September 13, 2022

9 Mistakes Runners Make When Training For A Marathon

Don’t make these nine mistakes if you want to run injury free and achieve a personal best time in your next marathon.

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So, you’ve decided to run a marathon. That’s great.

The marathon is a demanding but satisfying distance to master, so you must get your preparation and race execution right.

To save you some pain and frustration, this article will share nine mistakes that runners regularly make when preparing for a marathon so that you can avoid them.

Mistake 1: Running Without A Plan

As Benjamin Franklin once said, failing to prepare is preparing to fail.

Running is a simple sport, but if you want to run well and remain injury free, there’s more complexity and a certain amount of planning you must do.

The sooner you realise this and apply some structure to your training and fuelling, the better. Your performances will improve, you’ll suffer fewer injuries, and you’ll enjoy running more.

A good plan is the bridge between your goal and your personal best.

Mistake 2: Doing 30k+ Long Runs Regardless Of The Time It Takes

So many runners think you must clock a certain percentage of the marathon distance in a long run. It’s not unusual to see runners doing 30k, 32k, or 36k runs, even if it takes four or five hours to complete.

This thinking is nonsense. 2h 45m is plenty, regardless of the distance covered.

The stride length is the main difference between a runner covering 35k in 2h 45min and one who covers just 21km. Good runners are more conditioned and, as a result, have a longer stride.

The number of steps between the two runners is not significantly different, and it’s the steps that put stress on your joints, muscles, and connective tissues.

Legendary running coach Jack Daniels expresses my thoughts on this well in this short video.

Mistake 3: Training Too Hard, Too Often

When you run a marathon, almost all of the energy required to run the distance comes from your aerobic metabolism. Unfortunately, too many runners train at a pace that is too hard to prepare this vital system properly and show up on race day ill-prepared.

Mistake 4: Not Using Training Zones

You need training zones to know whether you’re running aerobically or anaerobically.

Training zones are tagged to markers of metabolic activity like lactate, fuel utilisation, and VO2max. For this reason, you can feel confident that when you follow a plan and train in the correct zone, you are training optimally, improving your performance while keeping your injury risk low.

I recommend you do your aerobic runs to heart rate and your anaerobic runs to pace.

Mistake 5: Not Doing Any Strength Training

Runners suffer a high rate of injury. It’s not surprising because running is a very high-impact sport that stresses the joints, bones, muscles, and connective tissues.

What is surprising is that most runners neglect strength training in their programme. In my view, strength training for runners is non-negotiable.

Strength training helps to correct the biomechanical imbalances that lead to many running injuries and conditions your body to be more resilient to fatigue.

Mistake 6: Not Doing Any Secondary Races

Racing is a skill; like any skill, you must practice if you want to improve. Well-timed and suitable secondary races are excellent preparation for your A-Race.

Secondary races give you feedback about your current fitness level and provide a place to practice your pacing skill and fuelling under race conditions. These races allow you to test your gear choices and make mistakes when the stakes are low.


Cut Race Times, Not Corners.

Racing at your potential and enjoying training is easy when you’re following the right programme.

Mistake 7: Choosing Secondary Races That Are Not Complimentary

If you choose the wrong secondary races or do them at the wrong time, these races can do more harm than good.

For a marathon, a half marathon on similar terrain and conditions, four to six weeks before your marathon is best.  

Mistake 8: Last-Minute Equipment And Fuel Changes

Any experienced runner will tell you that you should never try anything new on race day.

Purchase all new gear and test it weeks in advance. Chafing, blisters, pain, and poor performance are the side effects of last-minute gear changes.

Likewise, start experimenting and testing your nutritional strategy early to avoid bloating, nausea, cramps, and poor performance on race day.

It’s a good idea to research and find out what is used on course in your race and practice with those brands.

Mistake 9: Thinking You Can Eat Whatever You Want

You’re mistaken if you’re a runner who thinks they can eat whatever they want. You may look lean, but your body is likely riddled with inflammation under the hood.

Inflammation is a serious roadblock to good health and will slow your recovery and limit your performance.

Eat wisely.

Choose minimally processed whole foods that are rich in vitamins and minerals. Avoid refined carbohydrates that spike blood sugar and raise insulin levels.

PB Your Next Marathon

Avoid these nine mistakes, and you’re well on your way to a personal best in your next marathon.

We’d love to work with you if you need help preparing for your next race.

Sign up for a 14-day free trial of our online coaching. We’ll set up a training plan for you and arrange a 15-minute Zoom Call to meet and discuss your goals and the plan.

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Ben Pulham

Ben Pulham is the founder of Coached, a personalised training programme that helps runners & triathletes optimise, track and enjoy their training.