Zone 2 Cardio Is Still King (Here's the Data)
This week I read the actual studies behind three wellness headlines. Two were BS. One was real. Also: creatine might make you smarter.
The Creatine + Cognition Meta-Analysis
Read a meta-analysis on Pubmed examining creatine supplementation and cognitive performance. The finding: 5g/day of creatine monohydrate improved short-term memory and reasoning in sleep-deprived subjects by 10-15%. The effect was smaller but still present in well-rested subjects. The mechanism makes sense — your brain uses ATP just like your muscles, and creatine helps regenerate ATP. This isn't bro-science. It's actual science with decent sample sizes and proper controls.
Huberman on Cold Exposure
Watched Huberman's cold exposure episode and it was more nuanced than I expected. The key takeaway: cold plunges do increase norepinephrine (the alertness chemical) but the optimal protocol is way less extreme than social media suggests. You don't need ice baths. A 30-second cold shower ending achieves 80% of the neurochemical benefit. The remaining 20% requires suffering that most people won't sustain long-term. As with most interventions, consistency at a moderate dose beats intensity at an unsustainable dose.
Zone 2 Still Wins
A new longitudinal study tracked 12,000 subjects over 8 years and found that the single best predictor of all-cause mortality reduction was 150+ minutes per week of Zone 2 cardio — that's the conversational pace where you can talk but not sing. Not HIIT. Not strength training (though both help). The boring, easy, sustainable stuff that you can do while listening to a podcast. The effect was dose-dependent up to about 300 minutes/week, after which returns diminished sharply.
The BS Detector
Two headlines I debunked this week: "New study proves intermittent fasting reverses aging" (the study was in mice, n=12, funded by a fasting app company) and "Science confirms cold showers burn fat" (the study measured brown adipose tissue activation for 2 minutes post-shower, which is calorically meaningless). Always check: sample size, species, funding source, and whether the actual finding matches the headline. It usually doesn't.