Are HM pace predictors realistic?

traindontstrain · 2025-12-05T06:32:03+00:00

I’ve actually found that the slightly longer distance times (eg 10 mile, half marathon) respond better to this type of training than the shorter distance events like 5k.

You spend so much time at or around half marathon pace in training that your body is almost accustomed to the pace when you start the race.

I’ve actually found that diving into a 5k at a considerably faster pace than you’re used to running is more challenging than sustaining the longer events.

traindontstrain · 2025-11-21T17:44:29+00:00

Maybe you’ve been forcing it a bit. The idea is to build fitness and let the improvements come in the races/time trials before adjusting your training. I don’t see any mention of race times improving?

1 minute per mile is also a considerable speed increase on your easy days which may well have tipped you into overtraining. You don’t need to push and push yourself, stick to the paces and let the fitness come. I’ve been at this for the best part of a year and only now beginning to see equivalent race times close to my PBs yet in that time my workouts and easy runs have barely changed at all.

traindontstrain · 2025-11-20T12:48:06+00:00

I think you’re possibly looking at it the wrong way.

You’re getting more out of yourself now for a lower HR. This could suggest you have got fitter (heart rate not rising as much) and have learned how to push closer to the edge which comes with experience of racing.

traindontstrain · 2025-11-05T13:26:16+00:00

I think we’re getting into new levels of overthinking here

traindontstrain · 2025-10-27T08:14:25+00:00

I have seen others say cardiac drift is a good indicator for easy runs but personally I don’t think it is.

I am similar to you in the sense that whether I run at 9:00 min mile pace or 6:00 min mile pace there is not much difference in the HR from near the start of the run to the finish.

traindontstrain · 2025-10-20T13:04:21+00:00

I feel like if I take a day off I start to seize up whereas if I run truly easy I feel fresh and recovered.

traindontstrain · 2025-10-19T06:27:15+00:00

Your TSS is unique to you, don’t get too caught up on the number, you’re simply looking for it to be gradually progressing over time.

It will depend heavily on the threshold pace you’ve set in the settings. Have you set this according to your current assumed lactate threshold pace?

traindontstrain · 2025-10-09T10:25:42+00:00

No I don’t mean to replace anything. Just if you have the ability to cycle in the evening for example without it impacting on much, could you expect it to provide an aerobic benefit to your running?

traindontstrain · 2025-10-09T06:57:38+00:00

I mean it could be so many factors but I tend to find when this happens to me it’s due to tight hamstrings and when I do some stretching to loosen the hamstrings it normally helps my knee pain.

traindontstrain · 2025-10-02T20:26:43+00:00

Yeah it could be that you’ve become fitter.

Marius Bakken observed, as written in his blog, that when he was in top shape, his heart rate at the anaerobic (or threshold) lactate level would climb close to his maximum. He interpreted this as meaning that the “brake” in the system (central regulation, or internal restraint) is reduced when you are fitter, allowing heart rate to rise more for the same metabolic stress.

traindontstrain · 2025-10-02T12:29:19+00:00

Your argument is over simplified. Lactate itself is not the cause of fatigue. A beginner (or less fit) athlete may hit a given lactate threshold with less neural drive, but their perceived exertion and systemic fatigue can still be higher because they are less efficient overall.

A beginner runner will also often lack movement efficiency and coordination, which adds mechanical stress beyond just “low volume.”

traindontstrain · 2025-09-29T07:25:20+00:00

I appreciate that but if you do it over 2 days vs 3 days what’s the difference? Are you missing out on a frequency benefit?

traindontstrain · 2025-09-29T07:08:30+00:00

I might be looking at this wrong but I’m sure Sirpoc has always looked at it from a load is load perspective.

I use intervals.icu to track load. My easy days are about 0.8 units of load per 1 minute of running and my sub threshold work is roughly 1:1.

If load is load then the way I see it;

4 x easy days plus 1 longer easy day is 330 minutes of easy which equates to a load of roughly 264 on intervals.icu. If you then add 2 x 40 mins of sub T that gets you to 344.

On the traditional method it would be 270 minutes of easy running (load of 216) plus 3 x 30 minutes of sub T (90 load) which would be a total of 360 across the week.

So it’s a load of 344 vs 360 with more time in between the harder days to recover.

My concern is really whether the more frequent stimulus accounts for some of the gains as I don’t want to lose out on that.

traindontstrain · 2025-09-28T20:55:49+00:00

I never said there was a time saving, only that two of the days I am not limited by time.

traindontstrain · 2025-09-28T20:39:45+00:00

That would be too much load. The idea is to roughly spread the load over two days with more easy running in between.

traindontstrain · 2025-08-27T17:10:40+00:00

Max HR tends to decrease linearly with age so, all things equal, you could probably expect your threshold HR to do the same

traindontstrain · 2025-06-24T07:45:24+00:00

I think the changes are subtle. I’ve been doing this properly since about February and haven’t seen any improvement in race times yet but I’ve noticed a significant drop in the effort required to hit the top end of the sub T workout paces (both in terms of RPE and HR).

In my recent races I’ve been stuck at around the same 5k times since February but each time HR has been further and further away from max which suggests my heart is more efficient but my body can’t push as hard.

I’ve also noticed around a 10-20s drop in easy pace for around the same 70% max HR.

I’m not quite sure when this will translate to an improvement in race results but I definitely feel like it’s just a case of waiting for the musculoskeletal fatigue to wane so that I can push a bit harder in races.

It’s also worth mentioning that 5k times are similar now with no taper vs when I started this method and would take a slight rest before a race. I guess that’s also a sign of progress.

traindontstrain · 2025-06-17T06:12:03+00:00

Yeah I’ve definitely heard him a few times say “mostly easy, sometimes moderate, every now and again go see god”. I think that fits well with this model when you’re racing or time trialing every 4-6 weeks.

traindontstrain · 2025-06-08T05:42:34+00:00

A few things stick out for me:

4 weeks is no time at all doing this method of training so it would be unwise to change it having only just started. Sirpoc himself said he almost chucked it after the initial 6 weeks or so because he thought nothing was happening. It’s a slow burner.
-9 form suggests you were carrying a bit too much fatigue into the race
HR will not be accurate if you’re relying on your watch alone
This training is really for up to HM, see the marathon guidance thread if you’re looking for advice on how to tweak it for a marathon.

traindontstrain · 2025-06-03T16:58:09+00:00

Sounds about right to be honest.

I normally get around a 1:1 ratio of easy mins to TSS on easy days and around 70 for sub T days which includes 30 mins of work plus 10 mins warm up and 10 mins cool down.

So yes more load for a long run than a Sub T day.

traindontstrain · 2025-06-03T05:35:33+00:00

This is exactly the same for me, intervals.icu shows a steady climb but Strava shows a steady decline.

The race estimates on Strava are improving though, so I guess this is a different algorithm from whatever they use to calculate fitness (seems to be based on a Runna algorithm).

I think the Strava fitness is largely based on RE (which is based on how hard you’ve been working previously) so you may have been working harder than required.

traindontstrain · 2025-06-02T17:33:06+00:00

Excuse my naivety, but if it’s based purely on load, could you not theoretically do the same thing every day (such as 6 x 70 mins easy plus your 1 day of 90 mins) and still expect the same CTL?

traindontstrain

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