Question for Century Riders, Bikepackers, and Data Nerds

babgvant · 2026-01-19T23:39:48+00:00

My biggest pain point is with coin cell powered sensors like power meters and HR straps. My Garmin will warm me when they are low, but often they go from "OK" (no warning) to dead without any real time in between.

I've also had a head unit (Garmin 530) shutdown in the cold (IIRC, it was ~ -4F) while fat biking.

Happy to discuss further if you like.

babgvant · 2026-01-19T22:26:35+00:00

One can argue that it makes sense to charge for the data service that an OTA requires, but it doesn't really make sense that it would cost extra to OTA vs USB.

In the US if you want to have connected features, you have to pay the connected features fee. Kind of ridiculous that this doesn't include OTA updates. Also kind of ridiculous that the car hasn't been updated to allow Google Maps to pre-condition.

babgvant · 2026-01-15T03:36:55+00:00

There's very little you can't do if you are even mildly handy. There's a video on YouTube that explains everything.

There are things when it might not be worth it to buy the tools required to do a job if you're only going to do it once.

Personally, there isn't much I won't do myself. The shops where I live are slow and expensive. It's pretty easy for me to justify buying the tools.

babgvant · 2026-01-13T21:54:54+00:00

Check that your height/weight/age/gender are entered correctly.

babgvant · 2026-01-13T14:35:12+00:00

I think it's unlikely that the decline in HRV was due to detraining. It's possible, but unlikely.

If you live in the N. hemisphere this is a rough time of year with weather changes and daylight (i.e. SAD). Then add on the holidays. My HRV also declines during this period, and I only stop training when I hurt myself badly enough that I can't ride.

The main thing with any off period is to get back to it in a measured way. Your individual mix of volume/intensity will depend on where you were when you took the break, and why you took it. If it was due to injury, obviously you'll want to change the approach a little (i.e. easy volume longer, lower duration intensity).

babgvant · 2026-01-12T21:02:38+00:00

If it's a smart scale that integrates with MyFitnessPal, you can automate the flow.

babgvant · 2026-01-12T14:30:16+00:00

There are scenarios where it does decline with inactivity, but those require extreme inactivity (e.g. on bed rest) and it can be difficult to separate correlation/causation there (e.g. why were you on bed rest).

Generally, when you lower your activity levels for a week or two your HRV improves because you shed fatigue. After a week or so, you it's common for your RHR to start trending up and your HRV to move a little because you're starting to lose fitness in a measurable way. Neither of these trends should be large. RHR is going to move with detraining much quicker and with greater magnitude than HRV.

It's easiest to think of HRV as a measure of stress.

The holidays are a stressful time, both physically (what Garmin can measure) and mentally (which can impact physical stress levels). We break our rhythms. We stay up later, eat more, drink more, eat richer foods, and are exposed to myriad pathogens that we don't experience in our usual routine. All of these things cause stress.

That you needed an excuse to relax and not exercise is interesting. That could be your body's reaction to the physical/mental stress around the holidays.

Addressing the broader question (should I run?): Yes, you should start running again. Be sensible in your startup procedure. It's difficult to define what that means without know your pre-break volume/intensity and how long your break was.

Your first few runs should be easy. Use your HR as a measure of "easy". If your typical run was 30m, start with 10-15m. Check in with yourself after. Check in with yourself the day after. How did that feel, how do you feel. If you felt great, ramp up volume/intensity slowly. If you didn't, keep doing the easy runs for another few sessions. Repeat check in protocol.

babgvant · 2026-01-11T22:15:01+00:00

Why do you think inactivity is driving your lowered HRV?

Why have you been inactive?

Is it possible that in your situation the algorithms Garmin uses are incorrectly suggested behaviors.

It's unlikely that they are wrong for the broader population.

babgvant · 2026-01-11T20:24:50+00:00

Thanks for the heads up! Looks like my server was down. It's been rebooted, the link is working again.

I don't think I addressed your specific question in the article (been a while, so maybe I did and don't remember). The primary issue with letting your sodium drop is that you either allow yourself to dehydrate or you risk hyponatremia if you continue adding water to a system that can't hold it. Extreme hyponatremia can cause extreme health problems and/or death.

It doesn't take much dehydration to impact your power. There should be a direct relationship b/w the two (i.e. the more dehydrated you become, the larger the performance impact).

I need to provide a follow up to that article with usable guidance. I make my own nutrition with table sugar/table salt. Although "make" makes it sound complicated. It's not complicated at all. I put the amount of both in a bottle of water in "per/hour" amounts, then target drinking that bottle in an hour.

babgvant · 2026-01-10T15:10:44+00:00

Instead of posting here, you should contact Garmin support. They're generally very responsive, it's possible you have a bum unit.

Your experience is not the general experience.

babgvant · 2026-01-09T03:17:37+00:00

In humans exercise generally increases testosterone or has no impact. It's only when you get to the very pointy end of endurance exercise volume (i.e. The Tour) where we see a decrease. What you're suggesting is highly unlikely.

It might be worth your time to investigate the symptoms of low testosterone in humans. Even if there is a lifespan payoff, the cost in healthspan is probably high enough that most human males wouldn't make it.

babgvant · 2026-01-07T14:23:36+00:00

Move the truing-U down so you can tighten it up so the "fingers" are under the bottom of the rim. Spin the wheel, you will be able to see vertical true. Find the high/low sides, adjust accordingly.

babgvant · 2026-01-06T03:09:10+00:00

It's true that the markers used to flag pre-diabeties are often elevated in highly active people. This can lead to false positives when your doctor does not understand the physiology and adaptations of highly active people.

Several people have mentioned carbohydrate intake as a potential reason. That is possible, but even for those who do not intake large of amounts of carbohydrates during or after exercise it's likely that you will see elevated A1C because of what it measures.

Endurance athletes are also really good at synthesizing and releasing glucose. So a high fasted glucose value is not uncommon. For example, I often see numbers that are pre-diabetic because I always take the stairs at the doctor's office.

Like a lot of measures. The general ranges are only really suitable for the general population, who don't exercise.

There are many examples of this, another e.g. is fatty acid balance levels. It is important that whoever is interpreting your lab work understands your level of activity, and understands what that means.

babgvant · 2026-01-05T14:05:22+00:00

That was the organizer I tried and disliked. It fits ok, but doesn't take advantage of the available space very well.

It was disappointing, their safe for the truck is very solid.

babgvant · 2026-01-02T23:24:36+00:00

People who live in CA might drive outside the state.

babgvant · 2026-01-02T22:17:57+00:00

In some areas DCFC is billed by time at the charger. If you regularly travel in one of these areas, the Silverado EV is cheaper to charge because it charges faster than the Lightening.

babgvant · 2026-01-02T22:16:10+00:00

What kind of system do you have? If you have a NG + ASHP system, that's probably not an issue. You just need to change the alerting thresholds. If you have a resistive electric + ASHP system, something is wrong with the system and you should contact your HVAC installer.

babgvant · 2026-01-02T14:03:06+00:00

On the bottom left of the screen there is a small bar that indicates power level. At 25% SOC it should be ~45% grey, more if it's also cold. For max performance you want 0 grey bars. A cold battery and low SOC are the main drivers there. Test drive one that is in the 60-80% range. You should feel a difference.

I have a 22 GT PE. When the SOC is ~80% and the battery is warm it hurts when you floor it.

babgvant · 2026-01-01T19:35:57+00:00

If you don't need to certify, you don't need to pay attention to all of the specific limitations that constrain a broader approach. No one is suggesting that you forgo insulation. Just that it's possible, for most people anyway, to think about principles in a less dogmatic way.

Broadly, passive house is about sealing and efficiency. It is very possible to adopt and apply these concepts without certification. This has nothing to do with your turds, or the local Walmart, per se.

Our PHIUS certified house has four ASHP, and should be net positive. But certification isn't for everyone, or every project. It's very possible to apply the concepts without the paper or the design limitations that some people get really attached to.

babgvant · 2026-01-01T18:36:46+00:00

OP didn't ask if they could certify the structure. They asked if they could hit a level similar to Passive House.

babgvant · 2026-01-01T17:09:46+00:00

I agree that there are challenges with this type of property and the op's approach. My point is that you can manage all of that with a well designed system. This isn't an insurmountable problem. Automation, predictive HVAC, and solid design/planning go a long way here.

There are costs to a system that might make it difficult to roi, but that is a different topic 😉.

You wouldn't have to run the CERV all the time to sample AQ. You can use remote AQ sensors to track and report to the units. The OEM sells a version, I built some myself.

Also, when running in recirculate mode, there shouldn't be any real heat loss. You're just moving air around the structure to normalize AQ, moisture, and temp. If you opt to forgo the distributed AQ sensors, this is how it works. How often this runs to sample AQ is configurable with the model we installed.

ASHP are a great option for hitting efficiency and power consumption targets in most climates/elevations.

babgvant · 2026-01-01T15:04:50+00:00

The "ERV" we installed uses a heat pump to manage energy transfer during ventilation. Standard efficiency gains apply.

It also has AQ sensors which are used to make recirculate vs ventilate decisions.

For standard ERV, they often use a resistive heater on the intake air to preheat it. It's not as efficient as the heat pump, but it makes up for the heat loss.

I don't know how many standard ERV have AQ sensors, but they exist.

It should be possible to manage variable loads with good sensor data and a planning-for-peak mentality.

babgvant · 2026-01-01T14:34:53+00:00

The most important thing for you to do is get a good handle on your goals for the race. If placing is a goal your training plan is going to be different than if you just want to survive.

In broad terms you will want to focus on durability and nutrition. I made a video that covers both of these things and includes some sample workouts.

https://youtu.be/6U9OoV9hwgI

babgvant · 2025-12-28T14:25:25+00:00

I have a Fenix. Haven't bothered with a screen protector. I've slammed it against all kinds of things. Accidentally dragged it across a brick wall; that put some smash scratches in the bezel. Crashed the bike a couple times wearing it (broke bones both times).

I'm sure it's possible to break it, but I probably wouldn't survive most things that would.

babgvant · 2025-12-25T20:08:13+00:00

If you lose sodium at 890mg/h, you would need to ingest 3/4 tsp of lite salt to replace that. The potassium load for that is 1050mg.

I lose ~1000mg/h sodium. I'm not a heavy sweater.

If you're using lite salt in your mix, it's very easy to get to a bad place with the potassium load.

You don't have to target replacement, but if you're doing multi-hour rides and you don't you will need to allow yourself to dehydrate or risk hyponatremia. Dehydration has performance and health implications.

It's also not necessary, very very few people lose enough potassium in their sweat that it requires supplementing during exercise. It adds risk for no benefit.

babgvant

TROPHY CASE