My Running Pace Getting Slower? – 13 Reasons Why

Those just getting into running can usually expect a positive trend in their running pace if they are able to run consistently over time, and the same can be said for seasoned runners as well.

However, some may be experiencing that their usual running pace is trending downward, which can mean a variety of things — but not always bad. 

It’s perfectly common for a runner’s pace to shift throughout their training cycle for a myriad of reasons including recovery, rest, adaptation, overtraining, and undertraining. You need to listen to your body and respect what it is trying to tell you.

This deserves a deeper dive to further explain the nuances involved in someone’s training, so let’s dive into these topics.

Why is My Running Pace Getting Slower - 13 Reasons

13 Reasons You’re Running Slower

Factors that can affect running performance include:

  • Failure to replace worn-out shoes
  • Excessive stress levels
  • Inadequate calorie or carbohydrate intake
  • Changes in weather conditions
  • Poor sleep quality or inadequate sleep
  • Lack of variation in pace
  • Overtraining syndrome: excessive mileage
  • Lack of mental stimulation or engagement
  • Insufficient overall mileage
  • Inadequate long-distance runs
  • Iron deficiency
  • Weight gain
  • Insufficient or improper recovery practices
Why is My Running Pace Getting Slower – 4 Reasons Why

1. Gradual Slow Down from Variation in Training Paces

It’s quite normal and natural for your body’s physiology to train at different paces through the weeks, months, and years of running. This includes slowing down from time to time in order to rest your body and build back better in the future.

Although we’d prefer not to believe it, our bodies cannot infinitely improve. It needs time to build, perform, rest, and repeat.

This cycle usually means that all of your training paces (easy runs, tempo runs, interval runs, etc.) will shift — and even slow down — naturally from time to time which will impact your race time. 

This could probably be the most common reason for most runners’ slower paces, and it’s something you should expect. It just goes to show how much we have to let fitness come to us instead of trying to force it. 

2. Under Training

It’s common for runners to come off of a down period of training break running slower paces as well.

This can feel discouraging for many runners, as they hope to jump right back into their usual pace and routine that they had before taking a break. Unfortunately, this is not the case. 

In far rarer circumstances, undertrained athletes may also just not be working hard enough, in their runs, which means they are actually losing fitness little by little over time gradually decreasing their race times.

Perhaps you are skipping days, workouts, or recovery sessions consistently when you are scheduled to run. 

We all have busy lives and there are plenty of valid reasons that your running fitness may be getting slower, but it’s worth looking back at your training log to see if you fall into this camp. 

Under training does have a benefit, it means you are giving your body a chance to recover, but you will only be building a stronger self if you are also putting in the good training runs and workouts over time too. Under training is tricky, how much could it impact your performance on race day? A lot. 

-Did you pick the right training plan? I have 10 different plans that are suitable for different level runners. 

3. Overtraining

Because runners are usually motivated athletes, it is more common to see athletes overtraining than undertraining. This means that you are running harder or longer than your body can recover from. 

Training is fairly simple, it is a constant ebb and flow between breakdown and recovery, which leads to proper adaptations.

You need a good balance of both aspects to be improving in your running, but for most runners, it’s easier to “put in the work” during your runs, but then not give your body the chance to recover from the breakdown. 

Recovery is where your body is actually making improvements, the hard running is what breaks you down, so if you are breaking yourself down faster and harder than you are recovering, then you can actually regress in your training, meaning you will begin running slower, and the even worse trend towards injury or burnout

Hard running can also impact your race performance, meaning that regression will happen. 

If you find yourself in this camp, then consider taking a couple of days to cross-train, run extremely easy, or even just take some days off altogether.

Unless you’ve dug yourself a huge hole, your running performace should be returning to normal within a week or so. Just remember not to fall into the same habit that made you start running slower in the first place. Take the necessary time to recover. 

Along those lines, you can supplement your recovery by fueling properly with good nutrition and hydration, getting 7-9 hours of quality sleep each night, and running your easy days easily. I will get to sleep a little more in the next section. 

4. Rest, Recovery, and Adaptation Horizons

We touched upon this earlier, but if your pace is getting slower, then consider the usual recovery horizon that you give your body between harder bouts of running.

Do you really allow your body enough time to recover and adapt between workouts?

Take a look at your training longs and see how many easy days you get between your workouts. Most runners will have one or two easy days between harder efforts because that’s just the way they’ve learned to train. 

Think outside the box and consider that your body is far more than a training schedule on paper. Training plans are easy, but real life is messy. 

Too Much Stress

Perhaps you’ve had an extremely stressful or restless week due to work or family obligations. Maybe you went out and had a couple of too many drinks with your friends. Training to run your best race does not exist in a vacuum, running is a 24-hour sport. 

This is not to say you must avoid all of those stressful weeks, or not go out with your friends and family, but rather take it into account with your training because it absolutely has an effect on your recovery horizon.

If you are not recovering, your pace will probably get slower. It’s just that simple. 

-You might be interested in: How to Manage Pre-Race Anxiety

Sleep & Nutrition

If you did not get a full 7-9 hours of sleep or you didn’t fuel up properly after your run, then that needs to be factored into the recovery timeline and can dramatically impact your running performance.

Making sure you get enough sleep is very important as you train. If you need some extra rest days, then take them, and don’t beat yourself up too bad because it’s not worth it.

Sometimes you are too tired to even run, let alone take on a hard workout effort. You are still allowed your days off or your rest days, so stick to what you need and focus on getting back into running easily as soon as possible.

The key thing to remember is that everyone has setbacks every now and then in their training, but if they occur often enough, you will be sacrificing your long-term potential for short-term gains because the quality of your training will begin to suffer instead of improving with time. 

Tracking your sleep is important. I have this basic Garmin Forerunner 35 watch. It's not the most eye-catching as far as colors go but it does track my runs AND my sleep. 

Garmin 010-01689-00 Forerunner 35; Easy-to-Use GPS Running Watch, Black
14,984 Reviews
Garmin 010-01689-00 Forerunner 35; Easy-to-Use GPS Running Watch, Black
  • Easy-to use GPS running watch tracks how far, how fast and where you run.Special Feature:Bluetooth.Water Resistant: Yes
  • Estimates heart rate at the wrist, all day and night, using Garmin elevate wrist heart rate technology
  • Connected features: Smart notifications, automatic uploads to Garmin Connect, live tracking and music controls (when paired with a compatible smartphone)
  • All-day activity tracking estimates steps, calories and intensity minutes and reminds you when to move
  • Automatically uploads your data to Garmin Connect, our free online fitness community where you can join challenges, receive insights and share your progress as you meet your goals

Nutrition is the other half of the equation. Making sure you fuel up after your running sessions is paramount to recovery. Your body needs carbohydrates and protein in order to recover, so be sure you are getting enough to give your muscles what they need to rebuild stronger than before.

Recovery doesn’t always have to be days off, but it could mean that. Be smart with your training and you will reap the rewards later on down the road, just like everyone else who takes care of themselves properly during their running career always does. 

How to Know Why Your Pace is Slowing Down

So we covered the most common reasons why your pace may be getting slower and there are plenty of others too, but how can you know exactly which reason is responsible for you slowing down?

Well, it is possible you already intrinsically know. If not, then reflect on your training log and life schedule. Are you skipping a lot of runs? Are you running your easy days too hard? If you are preparing for a race, that's bad news. 

Are you not getting enough quality sleep?

Have you been going out a little bit more than usual? Are you coming down with an illness or are deficient in vitamins like iron or B12? 

Reflecting on these circumstances will help you identify why your running pace is getting slower. Knowing what is wrong is the first step to implementing the proper solution. 


It can be hard to look at your life and be critical, but it's how we grow and improve ourselves over time. Finding weaker links in our training and lifestyle then correcting them slowly can have a tremendously positive impact on our running. 

Make sure you are logging your training and following an intelligent plan, make sure you are sleeping well and generally eating nutrient-dense foods, and listen to what your body is telling you, as there is a good chance it subconsciously lets you know its needs. 

Do not be afraid to talk to a trusted coach, friend, or training mentor to better understand what training and life qualities you can add or subtract from your lifestyle. Be kind to yourself, trust your process, and your running performance will be trending upwards in no time.

Hi, Jeremy Here, 

I am the the guy behind Train for a 5K. On this site, I share everything that learned along my running journey. The content I create is the running training I wish I had before we started this journeyAbout Jeremy. 

I have run over 250 races including the California International Marathon, Clarksburg Country Run, and various other 5K & 10K races throughout the United States. I am a former Athletics department employee at University of the Pacific and Shoe Consultant with Dicks Sporting Goods

Other Great Running Tips

Last update on 2023-09-25 / Affiliate links / Images from Amazon Product Advertising API