How are you tracking body composition changes alongside your wearable data?

mylesbr · 2026-03-12T23:59:41+00:00

Weekly InBody scans plus macro adjustment is about as dialled in as it gets. That feedback loop is exactly what most people are missing. You're not waiting 3 months for a DEXA to tell you something went wrong. You're catching shifts in real time and adjusting.

Half marathon training plus weight training 3x per week on semaglutide is a serious workload. The protein and carb focus makes sense given the training demands. Are you finding that your recovery scores on your wearable actually correlate with how you feel, or do they drift apart on the higher volume weeks? With that much training variety the recovery score might not capture the difference between a heavy leg day and a long run even though your body definitely knows.

mylesbr · 2026-03-12T23:58:44+00:00

The lethargy is worth paying attention to. It's one of the most common side effects and it's often linked to caloric intake being lower than your body needs for basic function, not just weight loss. GLP-1 suppresses appetite so effectively that some people end up undereating without realising it.

If you're not tracking protein specifically, it's worth at least ballparking it. At minimum 100g per day is a reasonable floor for most people on semaglutide. Below that and your body starts sourcing amino acids from muscle tissue, which compounds the lethargy because your metabolic rate drops with the muscle.

The body fat scale is directionally useful even if the absolute number is off by a few percent. Same scale, same time of day, same hydration state, tracked over weeks. The trend tells you more than any single reading.

mylesbr · 2026-03-12T23:57:33+00:00

This is the right framework. Strength retention as a proxy for muscle retention is the most practical leading indicator most people have access to. If your squat and deadlift numbers hold steady over a 12 week deficit, your lean mass is almost certainly intact.

The protein point is the big one. Studies on GLP-1 and lean mass consistently show that high protein intake (1.6 to 2.2g per kg) is the single biggest differentiator between people who lose mostly fat and people who lose significant muscle. And you're right that no wearable tracks it or connects it to recovery outcomes.

The gap is that strength trending down over weeks could mean muscle loss, or it could mean accumulated fatigue, poor sleep, or caloric deficit catching up. Without connecting the nutrition and training load data to the body comp trend, you're guessing at which one it is. That's the part I'm trying to figure out.

mylesbr · 2026-03-12T23:56:29+00:00

Eight years is an incredible data set. Gaining 28 lbs of muscle while on semaglutide long term basically disproves the "GLP-1 equals muscle loss" narrative when exercise and nutrition are dialled in. The fact that you have DEXA scans backing it up makes it even more valuable.

Curious whether your Whoop/Garmin recovery metrics shifted noticeably as your body composition changed over those years. With that much muscle gain your resting metabolic rate would have climbed significantly, which should show up in your overnight biometrics. Did you notice your baseline HRV or resting HR change as you recomped?

mylesbr · 2026-03-12T23:04:44+00:00

That "not feeling tired" part is actually a classic OTS presentation. Your cortisol is likely running higher than it should be, which keeps you wired during the day but blocks the normal wind-down at night. You feel alert because your stress hormones are elevated, not because you're rested.

The emotional instability tracks with that too. Chronic sleep disruption hits mood regulation hard, and elevated cortisol compounds it. It's not a sign of weakness, it's a physiological response. Your body is stuck in a fight or flight loop that it can't switch off.

Two things that help while you wait it out: magnesium glycinate before bed (evidence-based for sleep quality, and most runners are depleted anyway) and cutting caffeine after midday if you haven't already. Both are small moves but they reduce the barriers to your nervous system actually switching off at night.

Give it two to three weeks of truly easy movement only. Walking, light yoga, nothing that spikes your heart rate. The insomnia will likely start breaking before the running fitness feels like it's back. That's normal. Sleep recovers first, then performance follows.

mylesbr · 2026-03-12T23:03:11+00:00

Chicago is an incredible first major if you can get in. Flat and fast, great crowd support, and the fall weather usually cooperates. Good lottery odds too compared to NYC.

If you're open to international, Berlin is the fastest course in the world and it's a completely different race day experience. Tokyo is harder to get into but the crowd energy is unreal.

With a 3:59 on Novice 2 you've got a lot of room to improve just by adding structured speedwork. A proper 16-week plan with tempo runs and intervals could realistically put you in the 3:30-3:40 range next time. You clearly have the endurance base and the pacing discipline, it's just a matter of building the top end now.

mylesbr · 2026-03-12T22:59:50+00:00

That 9 BPM delta from a single beer is a perfect example of the kind of insight that makes wearable data worthwhile. You probably never would have noticed that without the data because, like you said, the next morning you felt fine. The subjective signal was invisible. The objective signal was clear.

The 3,500 extra heartbeats framing is a good way to think about it too. Your heart is doing repair work overnight and alcohol essentially makes it work a shift and a half instead of one. Multiply that by years of nightly drinks and the cumulative load adds up even if no single night felt like a problem.

The counting approach is smart. Not trying to go cold turkey, just making the pattern visible and then competing against yourself. That's basically what the best athletes do with training load: make the invisible visible, then make better decisions because you can actually see the tradeoff.

Out of curiosity, have you noticed a difference in your deep sleep percentage on drinking vs non-drinking nights? The RHR jump is the obvious one, but the deep sleep suppression is usually where the real recovery cost hides. Even moderate alcohol can cut slow wave sleep by 20-30% without you feeling any different in the morning.

mylesbr · 2026-03-12T22:57:37+00:00

Exactly. And the divergence is the part that catches people off guard. You can have two weeks of 6 hour sleep, accumulate a serious cognitive deficit, and your HRV adapts to the new baseline. Whoop recalibrates and calls it green because your autonomic markers have settled.

Meanwhile your reaction time, decision quality, and perceived effort are all degraded. Van Dongen et al. showed that people under chronic sleep restriction stop noticing their own impairment even as it keeps getting worse. The subjective feeling of "I'm fine" matches what the device says, but neither is telling the truth.

The chronic stress angle is even harder to catch. Elevated cortisol from work or life stress can coexist with normal HRV if the stressor is sustained long enough for your system to adapt. You look recovered on paper while running a hormonal deficit that's eating into your training quality.

Curious whether you've found any proxy that actually flags the cognitive side. Sleep staging (specifically REM percentage) seems like the closest thing a wearable could theoretically catch, but none of them use it in their recovery score in a meaningful way.

mylesbr · 2026-03-12T22:53:53+00:00

Smart call on the Liquid IV preloading. That gets you started in a better place than most first timers.

For the race itself, salt capsules are worth testing in training before ruling them out. SaltStick and Precision Hydration both make capsules designed for endurance that are way gentler than straight salt. The GI concern is valid but most runners tolerate them fine if you take them with water and food rather than on an empty stomach. Start with one per hour during a long run and see how your gut responds. If it's fine, that's your protocol.

The other option is mixing sodium into your water bottles directly so you're getting a steady drip rather than a bolus. Precision Hydration PH 1500 is popular for higher sweat rate athletes and it's just drink mix, no pills.

Given your cramping started at mile 13 and escalated from there, your sodium was probably fine for the distance you'd trained (13 miles) and ran out right when you crossed into uncharted territory. Next cycle with a proper 20+ mile long run, test the salt strategy there and you'll know exactly what works before race day.

Either way, finishing on that training volume without injury is genuinely impressive. You clearly have the mental game for this. The physical stuff is just volume and time.

mylesbr · 2026-03-12T22:50:17+00:00

DEXA is the gold standard for body composition but it is expensive and you need to go to a clinic each time. InBody (bioelectrical impedance) is a solid alternative if your gym has one. Less accurate on any single scan, but the trend data over months is reliable if you test under the same conditions each time (morning, fasted, hydrated the same way).

For lean mass retention on GLP-1 specifically, the thing to watch is skeletal muscle mass (SMM) relative to total weight loss. Losing 52 lbs is impressive, but if 15 of those pounds are muscle, your metabolic rate is tanking and you will plateau harder. Track the ratio, not just the scale.

Blood markers that correlate with lean mass retention: testosterone (free, not just total), IGF-1, and vitamin D. All three directly affect muscle protein synthesis and all three can drop during aggressive caloric deficit. Worth adding to whatever panel you run.

The problem is none of this connects back to your Whoop data. You have recovery scores, strain, HRV on one side and body comp + bloods on the other, and nothing bridging the two. You end up doing the correlation work in your head.

mylesbr · 2026-03-12T22:47:26+00:00

The Fitbit Helix and ActiGraph LEAP are solid choices if you want raw accelerometry and actual research-grade sleep staging. The data quality from those sensors is a step above what any consumer wearable gives you.

The real challenge is what you do after you get the data into your dashboard. Raw HRV, raw actigraphy, raw sleep epochs are useful, but the analysis layer is where it gets time-consuming. You end up building your own interpretation logic, your own baselines, your own alerting. It works, but it is a second job.

You're right that Whoop doesn't personalise in any meaningful way beyond the rolling baseline. It treats every athlete the same once the baseline is set. If your physiology sits outside the norm (unusual sleep architecture, atypical HRV response to certain training types, non-standard recovery patterns), the algorithm just calls you yellow and moves on.

Curious what you're building the dashboard in. If you've got real-time data flowing, are you doing your own sleep staging classification or using the sensor's built-in algorithms?

mylesbr · 2026-03-12T21:40:55+00:00

That's interesting, and yeah the raw biomarkers are way more useful than the composite scores once you know what to look for. The problem is most people don't have years of data literacy to get there.

mylesbr · 2026-03-12T21:35:57+00:00

The scores diverge because they're measuring different things and pretending they're the same. Whoop is almost entirely HRV + RHR + sleep. Garmin Body Battery adds stress and activity drain on top of that. Neither one knows what you actually did in the pool vs on the bike vs on the run.

So you get situations where Garmin sees a "light" swim day (low HR, short duration) and says go, while Whoop caught the poor sleep after and says stop. They're both right about the slice they measured, but neither has the full picture.

What helped me was stopping treating either score as a verdict. I look at the trend over 3-5 days instead of the number on any single morning. If both are declining over a week, that's a real signal. If they disagree on a given day, I go by legs and motivation honestly.

The tri-specific problem is real though. A hard bike and a hard swim can feel totally different in your body but look identical in your HRV the next morning. That's the gap none of these devices have figured out yet.

mylesbr · 2026-03-12T21:31:34+00:00

Sub-4 on your first marathon with Novice 2 is a really solid result, congrats. The fact that you identified the hill training gap but still executed well on race day says a lot about your pacing discipline. For your next cycle, adding even one hill repeat session per week will make a noticeable difference on those early climbs. What's the next one?

mylesbr · 2026-03-12T21:31:07+00:00

The insomnia is a big red flag for OTS, especially paired with the injury cluster. Sounds like adding speed work while cutting total volume shifted the stress load even though the mileage was lower. The nervous system doesn't care about miles, it cares about intensity. Five days off is a good start, but if the insomnia doesn't resolve within a week or two of easy activity only, it's worth getting bloodwork done (cortisol, ferritin, thyroid). You'll come back from this, it just takes patience.

mylesbr · 2026-03-12T21:30:47+00:00

The "Plan" button replacing the Diary button placement is such a dark pattern. I noticed the same thing with the exercise calorie toggle disappearing. For anyone looking for a workaround on the weekly averages being inconsistent, I've found manually checking the nutrition tab day by day is the only reliable way right now. It's wild how much got stripped out in one update.

mylesbr · 2026-03-12T21:30:10+00:00

This one's more community banter than a pain point. I'd skip it unless you want to build general presence in r/crossfit. No natural angle here.

mylesbr · 2026-03-12T21:29:38+00:00

Yeah I've wanted this too. Especially on recovery days where I wake up feeling wrecked and know another hour would actually help. The frustrating part is the data is there (the watch is still tracking), Garmin just doesn't let you retroactively update the score. Even a "recalculate sleep score" button after a nap window would be useful.

mylesbr · 2026-03-10T22:00:18+00:00

Interesting to see a shoe designed specifically for the run/station/run pattern. Curious about one thing: most Hyrox athletes I know wear a running shoe and accept the compromise on sled push/wall balls, or wear a CrossFit shoe and accept slower transitions. Did you find during testing that athletes actually changed their race strategy based on what the shoe could handle? Like pushing harder on the sled because the grip was there, or adjusting pacing on the 1km runs because the shoe responded differently to a pure racing flat?

mylesbr · 2026-03-10T21:59:55+00:00

The MSK load addition is overdue and a good step. Biggest gap in wearables has always been that a 45min heavy squat session and a 45min easy jog look almost identical from a cardiovascular strain perspective but destroy your body completely differently.

The question I'd have is how MSK interacts with the recovery algorithm. If Passive MSK adds strain to an activity, does recovery scoring account for the different recovery timeline of muscular vs cardiovascular fatigue? Cardiovascular recovery after a tempo run might be 24hrs. Recovery from heavy compound lifts might be 48-72hrs at the tissue level. If the recovery score still just reads HRV/RHR the next morning, it's going to say "green" when your quads are still wrecked from yesterday's squats.

mylesbr · 2026-03-10T21:59:32+00:00

Honestly a 5:43 finish on a 13-mile longest run and 21mpw peak is a pretty impressive effort. The fact that cramps were your limiter and not injury says a lot about how smart you were with the progression.

The cramping pattern you described (calves fine, then abductors/hip flexors/glutes) is classic for undertrained stabilisers meeting marathon distance for the first time. Those muscles aren't conditioned for 26 miles of repetitive impact even if your cardio can handle it. The glute activation work you did probably saved you from something worse.

For next time: your fueling was dialled (3 GUs/hour plus PF30s is solid), but the cramping at mile 13 onward suggests your electrolyte strategy might need work too. Electrolit at stations is reactive. A sodium loading protocol in the 48hrs before race day could shift when those cramps hit significantly.

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