Name: GAPMNN B ( GAP pacing data field )
Rating: 5 (1 reviews)
Author: Woodster

“GAPMNN” ( Grade-Adjusted Pacing Manager )

This app is free, but donations are more than welcome & encourage further development: https://buymeacoffee.com/woodster

Feel free to make any feature suggestions or if anything is broken do let me know!
66 devices supported – hopefully it works on yours 

Description
GAPMNN is a gradient-adjusted pacing app which uses your Garmin's barometer & built-in GPS to provide precision pacing guidance for undulating terrain. Works well for long-slight inclines and declines where you can bank marginal gains without burning out. Pace or speed shown is the average for the whole activity – ideally suited to racing 5k/10k/HM and more. You can pace directly off the race time without having to worry about pace per km then having to do maths whilst you’re running to multiply the pace by the total distance.

Note that there are two apps as listed below which can have their own configuration:
GAPMNN_A: pacing data field, saves GAP KPH to watch with 4 decimal places for precision pacing
GAPMNN_B: pacing data field - 2nd copy to allow you to view in different units so you can mix and match (save disabled)

How it works
Gradient is calculated every 5s – the first 5s will show “BARO STARTUP” as there is no data yet, after a few 100m the average pace will have settled down & you can start adjusting it according to your target.

So for running uphill it will show a higher speed than your real average speed & for downhill the opposite, so will show lower.  For perfect pacing you'd want to slow down for the up-hills and speed up for the downhills to maintain constant GAP. Note that some downhill gradients aren’t safe to sprint down so the GAP could get worse, but normally there’s some better terrain just round the corner to make up the difference!

Choosing the Paces
The default is kph which is shown to 4 decimal places & many others which can be accessed as shown below – starting from watch screen:
1. press START
2. select “Run” or any other profile which supports speed or pace*
3. press the UP button 
4. click on “Connect IQ fields”
5. move up/down to select either of GAPMNN_A or GAPMNN_B
6. long-press the UP button (MENU)
7. select the speed/paces you want/don’t want by clicking START to light them up green!

If more than one is selected the app will cycle between them. You may prefer to have GAPMNN_B installed & have one selected from each, then you can position both apps wherever you want!

Here’s the list of paces:
KPH (to 4 decimal places) – good if you’re used to treadmill speed or want to run max distance in an hour
MPH (ditto) 
KM Pace (with 1/100ths of a second e.g. 03:59.99)
Mile pace (ditto)
5k Pace – KM pace x 5 e.g. 5min/k gives 25:00.00
10k Pace e.g. 42:30.00
10mi Pace e.g. 75:00.00 for 1hr 15mins
HM (Half-Marathon) Pace – note minutes go up to 99:59 then it flips to HH:MM:SS (1hr 40mins upwards)
M (Marathon Pace)
50k Pace
100k Pace
100mi Pace
Bowstones! (6.8-mile pace) – a local running club favourite

You may wonder why you need 4 decimal places to 1/100ths of a second for pace, this is because it’s an overall average & when you’re well into your race you can make small adjustments as soon as you see the pace/speed drop below what you want, using the extra decimal places.

Screen Layout
You may like the 3-way horizontal layout as seen in images, but the data field will auto-size to any layout.
Note the top one is GAPMNN_A, middle one is GAPMNN_B (installed separately) & the bottom one is Garmin’s average speed.
