There is nothing more frustrating than being midway through a training run or race, feeling smooth and consistent, and then your watch starts telling you to speed up. GPS issues can be down to dead spots because of dense trees or tall buildings, or because of outdated mapping data. If you run regularly in the same area, you might be able to spot when your pace data is going to be out of whack because the GPS is not being picked up correctly.
Tip: Canary Wharf along the London Marathon route is one area where your GPS won't work properly.
If you are relying on your watch to help keep your pacing in check then this can be off-putting. Here are some tips on what to do if your pace suddenly changes but you don't feel your effort or pace has:
Trust your pacing judgement
Training not only gets you fit for race day but it helps you to practice your pacing. It is important to try and learn how different paces feel so when it comes to race day you aren't relying solely on your GPS watch to get you round. In your training runs, once you have dialled into a pace, practice ignoring your watching and running to feel. It will feel strange and difficult to do at the start, but eventually, you'll be able to trust your pacing judgement and become less reliant on checking your watch every few hundred metres.
Write out your splits
You will know what 1km or 1 mile splits you are looking to run based on your target pace. For example, if you are aiming for a 1h 30min half marathon, you will be aiming for 4:16 for each km. It is also worth making a note of your 5k splits. For a 1h 30min half marathon, this would be:
5k = 21:20
10k = 42:40
15k = 1:04:00
20k = 1:25:20
Write these down on your hand or arm, and as you pass each 5k marker, check your overall time to see if you are on track. This is more reliable than your lap split and it will give you the reassurance that you are pacing it well or if you need to speed up to get back extra seconds!
Use the 'Lap Pace Average' function
When we run to pace we are running to the live pace. This is the pace that our watch thinks we are running at every second (this will vary amongst manufactures) 'getting the most out of your smartwatch articles. Another option is to use the 'Lap Pace Average' setting and this will give you the average pace for each lap. This setting is more accurate as it is taking your whole lap pace rather than relying on the live GPS.
While a smart watch is great for helping us pace our run towards our goal, it is best not to be overly reliant on this and practice pacing by learning what different efforts feel like. You can do this throughout your training in your interval, tempo and long run sessions. Using a combination of the watch and your own judgement, will help you run smoother towards your finishing target!