What Eight Drinks Cost My Nervous System

27 March 2026 · Myles Bruggeling

I had eight drinks last Friday night. Not proud, not ashamed. It was a social thing. Good time with good people. But I track everything, so I know exactly what it cost me.

My HRV the next morning was 26.4. For context, I’d been sitting around 30 to 33 most of the week before that. Not amazing numbers for a 52 year old, but consistent. Stable. Then I poured petrol on it.

Saturday was a write-off. Eight minutes of exercise. 3,583 steps. My body basically said no thanks. Active calories dropped to 358 compared to the 1,029 I’d burned the day before. I ate well though. 202 grams of protein, 34 grams of fiber, about 5,400 kJ total. The body wanted fuel even if it didn’t want to move.

The six day climb back

Here’s what my HRV did after that Friday night:

Day HRV Exercise (min) Steps
Sat 22 (hangover) 31.8 8 3,583
Sun 23 28.9 136 14,593
Mon 24 32.6 116 12,931
Tue 25 33.0 80 13,993
Wed 26 32.0 67 6,320
Thu 27 (today) 39.1 - -

It took six full days for my HRV to get back above where it was before the drinks. Six days. And I trained hard through most of them. Sunday I did 136 minutes of exercise and walked nearly 15,000 steps. Monday was 116 minutes. My body was working, but the nervous system was still digging itself out.

The thing that got me was Thursday morning. I woke up, checked my watch, and there it was. 39.1. That’s the highest HRV reading I’ve had since mid-March. My resting heart rate overnight was sitting at 51 average with a minimum of 45. The system had finally reset.

What else moved

Weight dropped from 79.7 kg on Monday to 78.05 by Wednesday. Some of that is probably water regulation after the alcohol, not actual tissue loss. But it’s still a 1.6 kg swing in three days while eating 145 to 165 grams of protein daily.

VO2 max held steady at 39.9 all week. It’s been slowly creeping up from 39.08 at the start of March. Not dramatic movement, but the trend line is going the right direction with Hyrox four months out.

My running form data from Tuesday and Wednesday tells a story too. Stride length went from 0.96m to 0.92m. Ground contact time went up from 278ms to 285ms. Running speed dropped from 9.2 to 8.9 km/h. I was running tired. The power output barely changed (205W to 204W) but everything else got a bit sloppier. That’s what accumulated fatigue looks like in the numbers.

The real cost

Eight drinks didn’t just ruin one night and one morning. It created a six day recovery deficit. During that time I trained hard, ate well, got reasonable sleep, and my nervous system still couldn’t fully recover until day six.

For someone training six days a week for Hyrox and a half marathon, those six compromised days represent real lost training quality. My HRV being suppressed means my autonomic nervous system was still dealing with the inflammation and stress response from the alcohol instead of adapting to the training stimulus.

I’m not saying I’ll never drink again. I’m saying the data makes it hard to pretend it doesn’t matter. Eight drinks cost me nearly a week of optimal recovery. At 52, that’s a week I can’t really afford to waste.

The numbers

Next Friday I’ll probably have a sparkling water.


X Thread

1/ Eight drinks last Friday. HRV dropped to 26. Took SIX DAYS to climb back to 39. That’s nearly a full week of compromised recovery from one night out. Here’s what I learned tracking every metric through it.

2/ Saturday was a write-off. 8 minutes exercise, 3,583 steps. But I still ate 202g protein and 34g fiber. The body wanted fuel. It just didn’t want to move.

3/ Trained hard Sun through Wed (80 to 136 min/day) and the HRV barely moved. 28.9 → 32.6 → 33.0 → 32.0. My nervous system was still cleaning up the mess while I was trying to train through it.

4/ Thursday morning: 39.1 HRV. Highest since mid-March. Running form also told the story. Stride shortened from 0.96m to 0.92m. Ground contact went up. Speed dropped. I was running tired and the watch knew before I did.

5/ At 52, training for Hyrox (July) and a half marathon (Aug), a week of compromised recovery is expensive. The data doesn’t lie. Eight drinks cost six days. Next Friday I’ll have a sparkling water.

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