For me 5km 17:58, 10km 39:23
I set my 10km last year, and feel that I would be at least 1min faster today.
My recent 5k run was an Avg HR of 167, however, after first 5mins it was 172-174bom, according to Garmin, my Threshold Rate is 169bpm. In theory I should be able to hold roughly this pace for one hour, so would expect my 10km pace to be only slightly lower
yes, not the difference between 5 and 10km PBās themselves. although I see I missed your lower number and only remembered the much higher one before you ālearntā, so youāre not an outlier.
@JibberJim I think mine is down to my weakness being muscular rather than cardiovascular
The muscles give up waaaaay before my CV system is feeling the same kind of strain
That test report I posted about further up had a comment along the same lines saying I only hit 4mmol at 93% of peak power on the bike.
ā lactate first starts to increase (328W or 139 bpm) and the anaerobic threshold where the change in lactate increases sharply, often corresponding to a lactate concentration of 4mmol/litre of blood (377W and 150bpm). The anaerobic threshold is known to be the best predictor of cycling performance in many cycling events therefore any training to improve this value will provide the greatest cycling performance improvements. To better understand threshold powers they can be expressed as a percentage of your peak power with LT ideally occurring at 50-60% PP and AT 70-80% PP. Currently, LT is 81% PP and AT 93.5% PPā
To me that reads as I can trundle along quite happily/powerfully/quickly right up until a point.
I hit that point and then suddenly it all gets very painful very quickly.
The question then is, is that a good thing for long distance triathlon or not?
Had a couple of runs since I last updated, a capped half mara on Sunday & todayās 10k. With the weather turning bitingly cold the last couple of days - & half an eye on a FTP test tomo 
- Iāve become a bit of a negative ninny & had to have a word with myself to get out today.
Anyway
28/02 50:29 @ 127 100mtrs climb & 49:58 @ 137 75mtrs climb, cold initially then pretty nice
02/03 48:25 @ 139 cold wind & stymied a bit at road crossings
Having done an ultra yesterday, went for a 16km recovery run today (My wife organises a ālongā run on 1st Sunday of the month). 4:57 average pace, Avg HR 127bpm. Getting clost to @funkster
I find when I run again after a big run when massively fatigued, my HR remains very low. I have barely got it above 120 for an hour, this is whilst doing a pace where it is normally around 130.
So this could be a red herring. (Donāt want to burst your bubble btw and great run 
)
Thanks, I am also aware of this, and definately see the same. Normally after a big day, my HR refuses to come up, and I feel like I am in treacle: On Sunday, it took around 3km to shake the stifness out, but felt pretty good running, certainly no treacle. However, I am sure that my HR was low because of the run on Saturday
I did a fartlek session on Monday, so Iām down to one flat, capped 10k run a week & it was today. First time under 48mins although I think I could get nearer to 45 if I ran closer to the calculated cap of 147bpm.
11/03 47:49 @ 142 flat, circular course with windy conditions
I would need to get a chest HRM for this, otherwise the numbers would be worthless (far too high with wrist HR). Since the world went to pot and Iāve not been training specifically for events, Iāve not bothered replacing my last one.
From my run on Tuesday, I did a 44:06 10km (within a 60 min run) with an overall Av HR of 132 (75% is 140) 
Another data point - is it really a month since my last one?
| date | time | pace | av hr | max hr | cad | str |
|---|---|---|---|---|---|---|
| 14-Jan | 41:25 | 04:09 | 137 | 148 | 160 | 1.51 |
| 28-Jan | 43:38 | 04:22 | 128 | 142 | 158 | 1.45 |
| 05-Feb | 43:25 | 04:20 | 129 | 142 | 158 | 1.46 |
| 12-Feb | 43:29 | 04:21 | 129 | 136 | 159 | 1.45 |
| 12-Mar | 42:33 | 04:15 | 132 | 142 | 159 | 1.49 |
Struggled to keep the HR down today, too much effort in to the headwind. So decided to pick my feet up a bit and keep the effort a bit higher on the downhills. Also, slightly different route meant I hit 10K at a net downhill so the pace is a little generous.
Must get over the the 5K thread soon for another benchmark. Will wait for the wind to subside a bit first.
What?!?!
Net downhill with a tailwind, surely?
Did you get to the toilet in time?
Had a poor couple of weeks, felt wiped. Although my HR ceiling for this thread is 149, Iāve been trying to cap much nearer 140. Today I said āFuck itā & ran closer to the 149. Started & ended with a headache.
18/03 45:53 @ 146 flat, circular course with a bit of wind
Bit longer than 10k. Did a sub 1h30m HM today. Never would have thought that a sub 1:30HM would feel easy
@gingerbongo did the same!
Seemed like the day for it!
I seem to be coming back to life a little bit on the running front. Didnāt initially go out with any plan, other than an easy 30 mins or so. But once i got going decided to keep to a zone 2 effort around 160bpm. Made me think about this thread and, low and behold, my calc was 160.
Avg HR for my run today was only 150, though that included a wonky first km (strap gave me a 106 average, but it wouldāve been more like 145), so iād say 155 as the total average bpm.
Anyway, ran 7km with about 70m elevation at 4.23 pace. Assuming a bit of HR drift and me finding some more flat kms (there arenāt any) that would likely have extrapolated up to about 160 i would guess.
So pretty happy with that. No wind and truly flat, i reckon iāll be nearing sub 4.20 pace. Might pop over to Exmouth and try that theory out on the seafront over the next week or so.
1st time 10km under 45mins AND under 130bpm, (70% of my MHR). This is a bit of an personal milestone
Have neglected this for a while. Frankly Iāve neglected running for a while unless you count pre-breakfast, still half asleep plodding. So I dug the 4% out from the back of the cupboard for the 1st time since my marathon last January, just for something different. No wow factor like I remember, either rose tinting or they have lost their edge, and for some reason my HR was way up despite feeling fairly comfortable.
| date | time | pace | av hr | max hr | cad | str |
|---|---|---|---|---|---|---|
| 14-Jan | 41:25 | 04:09 | 137 | 148 | 160 | 1.51 |
| 28-Jan | 43:38 | 04:22 | 128 | 142 | 158 | 1.45 |
| 05-Feb | 43:25 | 04:20 | 129 | 142 | 158 | 1.46 |
| 12-Feb | 43:29 | 04:21 | 129 | 136 | 159 | 1.45 |
| 12-Mar | 42:33 | 04:15 | 132 | 142 | 159 | 1.49 |
| 09-Apr | 41:50 | 04:11 | 141 | 156 | 160 | 1.50 |
Hopefully I can get back to more regular runs and closer to the 130 ceiling as I felt it was helping.
Interesting run yesterday, running group Half Marathon. Started off nice and easy just having a chat while running. After 6km, upped the pace and ran the rest of the HM around 4:02m/km (apparently my fastest ever 15km). Never felt that I was really pushing, Avg HR for this 15km was 147bpm, so still Zone 2.
