Evidence-based writing on health data, wearables and what the research actually supports.https://hydra-app.com/https://hydra-app.com/blog/forward-head-posture-habits/https://hydra-app.com/blog/forward-head-posture-habits/Exercise reliably changes craniovertebral angle across 7 RCTs and 627 people. 10 habits the research supports, and what the pain evidence really shows.Mon, 24 Aug 2026 00:00:00 GMThttps://hydra-app.com/blog/fix-bad-sleep-habits/https://hydra-app.com/blog/fix-bad-sleep-habits/Across 60,977 people, sleep regularity beat sleep duration as a mortality predictor. 10 sleep habits with real numbers behind them.Mon, 24 Aug 2026 00:00:00 GMThttps://hydra-app.com/blog/dry-sauna-benefits-evidence/https://hydra-app.com/blog/dry-sauna-benefits-evidence/Over 20 years, sudden cardiac death hit 5.0% of frequent sauna users vs 10.1% of weekly users. What the Finnish data shows, and its limits.Mon, 24 Aug 2026 00:00:00 GMThttps://hydra-app.com/blog/why-am-i-always-tired/https://hydra-app.com/blog/why-am-i-always-tired/14% of US adults have iron deficiency and most would never be tested. Three measurable, commonly missed contributors to persistent tiredness.Mon, 24 Aug 2026 00:00:00 GMThttps://hydra-app.com/blog/morning-routine-longevity/https://hydra-app.com/blog/morning-routine-longevity/The brightest tenth of daytime light exposure tracked with 17-34% lower mortality across 88,905 people. A morning routine built on three findings.Mon, 24 Aug 2026 00:00:00 GMThttps://hydra-app.com/blog/anti-aging-lunch/https://hydra-app.com/blog/anti-aging-lunch/Top-quintile diet quality tracked with 86% higher odds of healthy aging at 70 across 105,015 people. What that looks like as an actual lunch.Mon, 24 Aug 2026 00:00:00 GMThttps://hydra-app.com/blog/evening-routine-longevity/https://hydra-app.com/blog/evening-routine-longevity/Brightest-tenth night light exposure tracked with 21-34% higher mortality across 88,905 people. An evening routine built on the light and meal data.Mon, 24 Aug 2026 00:00:00 GMThttps://hydra-app.com/blog/recovery-techniques-distance-runners/https://hydra-app.com/blog/recovery-techniques-distance-runners/Across 99 studies, massage beat ice baths 5 to 1 for soreness and stretching did nothing. What recovery methods rank for 5K and 10K runners.Mon, 24 Aug 2026 00:00:00 GMThttps://hydra-app.com/blog/best-exercise-to-live-longer/https://hydra-app.com/blog/best-exercise-to-live-longer/Across 147,374 people over 30 years, combining aerobic and resistance training tracked with 45-58% lower mortality. The dose numbers for each.Mon, 24 Aug 2026 00:00:00 GMThttps://hydra-app.com/blog/how-to-improve-hrv/https://hydra-app.com/blog/how-to-improve-hrv/Exercise raised RMSSD with a pooled effect size of 0.84 across 16 trials. What moves HRV, what suppresses it, and why your number is not comparable.Mon, 24 Aug 2026 00:00:00 GMThttps://hydra-app.com/blog/how-to-improve-your-running/https://hydra-app.com/blog/how-to-improve-your-running/Strength training improves running economy and polarized training improves VO2peak, but neither does what most runners assume. The evidence, with effect sizes.Mon, 24 Aug 2026 00:00:00 GMThttps://hydra-app.com/blog/ice-plunge-health-benefits-evidence/https://hydra-app.com/blog/ice-plunge-health-benefits-evidence/A meta-analysis of 11 trials and 3,177 adults found cold plunges cut stress at 12 hours, raised inflammation acutely, and did nothing measurable for immunity.Mon, 24 Aug 2026 00:00:00 GMThttps://hydra-app.com/blog/air-quality-blood-pressure/https://hydra-app.com/blog/air-quality-blood-pressure/Ten randomized trials found air purifiers cut systolic blood pressure by about 4 mmHg. The PM2.5-to-blood-pressure evidence, with effect sizes and limits.Mon, 24 Aug 2026 00:00:00 GMThttps://hydra-app.com/blog/improve-home-air-quality/https://hydra-app.com/blog/improve-home-air-quality/Gas stoves raise indoor NO2 by 4.0 ppbv and it reaches the bedroom. Four home air quality interventions ranked by what randomized trials actually measured.Mon, 24 Aug 2026 00:00:00 GMThttps://hydra-app.com/blog/plasticizers-bpa-phthalates-health/https://hydra-app.com/blog/plasticizers-bpa-phthalates-health/A global model attributed 356,238 deaths to DEHP exposure in 2018. What the phthalate and BPA evidence supports, and how much is modelled rather than measured.Mon, 24 Aug 2026 00:00:00 GMThttps://hydra-app.com/blog/reduce-plasticizers-at-home/https://hydra-app.com/blog/reduce-plasticizers-at-home/Three days of fresh, unpackaged food cut urinary BPA by 66% and DEHP metabolites by over half in 20 people. What that study tested, and what it did not.Mon, 24 Aug 2026 00:00:00 GMThttps://hydra-app.com/blog/heart-disease-prevention-tests/https://hydra-app.com/blog/heart-disease-prevention-tests/The 2026 ACC/AHA guideline added lifetime Lp(a) testing and lipid screening from 19. Which tests are recommended, at what age, and why it changed.Mon, 24 Aug 2026 00:00:00 GMThttps://hydra-app.com/blog/glp1-lean-mass-body-composition/https://hydra-app.com/blog/glp1-lean-mass-body-composition/Across trials, lean mass accounts for anywhere from under 15% to 60% of weight lost on GLP-1 therapies. That spread is the story.Thu, 20 Aug 2026 00:00:00 GMThttps://hydra-app.com/blog/semaglutide-heart-benefit-weight-loss/https://hydra-app.com/blog/semaglutide-heart-benefit-weight-loss/In SELECT, 17,604 adults on semaglutide saw fewer cardiac events regardless of how much weight they lost. Why the scale is a poor risk readout.Thu, 20 Aug 2026 00:00:00 GMT