
HRV Cardiovascular Risk Calculator: What Your Heart Rate Variability Reveals
Score your SDNN against the 24-hour HRV bands used in heart research, see what population studies link low HRV to, and what to do about it.
Men's
Hormones, sleep, heart, prostate, and the numbers on your last blood panel.
Score your SDNN against the 24-hour HRV bands used in heart research, see what population studies link low HRV to, and what to do about it.
Check your resting heart rate against a 2016 CMAJ meta-analysis of 46 cohort studies and 1.2 million people. Find your heart-rate group and what to do.
Learn how to improve sleep quality for men over 40 with 12 evidence-based tips covering temperature, light, exercise, supplements, and more.

Score your SDNN against the 24-hour HRV bands used in heart research, see what population studies link low HRV to, and what to do about it.

Check your resting heart rate against a 2016 CMAJ meta-analysis of 46 cohort studies and 1.2 million people. Find your heart-rate group and what to do.

Learn how to improve sleep quality for men over 40 with 12 evidence-based tips covering temperature, light, exercise, supplements, and more.

Recognize the 10 most common signs of low testosterone in men over 40, what your levels should be, and when to see a doctor.

Your gut microbiome affects testosterone through 3 direct pathways. Here's the research on gut health and testosterone for men over 40, explained.

Statins reduce testosterone 19 ng/dL on average. Low-fat diets cut T 15%. The research on cholesterol and testosterone for men over 40, explained.

DIM shifts estrogen metabolism in men, but it doesn't lower total estrogen. Learn what the research shows about DIM dosage, benefits, risks, and when to use it.

Low sex drive in men over 40 has specific, testable causes: low free testosterone, high SHBG, cortisol, and medications. Here is how to diagnose and fix each.

SHBG rises with age and binds testosterone, making your total T reading useless. Learn why high SHBG cuts free testosterone in men over 40 and how to fix it.

DHT, not testosterone, drives male pattern baldness. Here's the biology of follicle miniaturization, what works to stop it, and the real tradeoffs of blocking DHT.

High estradiol causes gynecomastia, low libido, and mood shifts in men. Learn the symptoms, why it rises after 40, and what the research shows about lowering it.

Normal testosterone for men runs about 264 to 916 ng/dL and falls 1 to 2% a year after 40. Age centiles, clinical thresholds, and when to act.

Most men test 'normal' on total testosterone but have low free T. This protocol targets both SHBG and production to raise the number that actually matters.

Cortisol rises with stress and short sleep. Seven interventions for men over 40, what each study actually found, and how to build them into one protocol.

Waking at 3am is not random. Seven biological causes explain it in men over 40, each with a targeted fix. Evidence-based, study-cited guide.

High cortisol symptoms in men over 40: broken sleep, belly fat, low drive. What the research shows about symptoms, testing, and 8 ways to lower it.

Calculate your insulin resistance score using the clinically validated HOMA-IR formula. Enter your fasting insulin and glucose to get your score and evidence-based interpretation.

Calculate your testosterone impact zone from sleep duration. Based on JAMA 2011 data showing a 10–15% T drop after one week of 5-hour sleep restriction.

Check your testosterone against the two mortality thresholds from a 2024 Annals of Internal Medicine study. Find out if your level is in the danger range and what to do.

Sleep apnea affects 30-40% of men over 40 and goes undiagnosed in most. Learn the 8 key symptoms, the testosterone connection, and when to get a sleep study.

Natural joint pain remedies for men over 40 backed by research. 12 strategies to reduce pain, protect cartilage, and stay active well into your 50s.

A research-backed breakdown of TRT pros and cons for men over 40, covering benefits, risks, delivery methods, and the key questions to raise with your doctor.

12 evidence-based prostate health tips for men over 50 — covering PSA screening, diet, exercise, supplements, and warning signs you shouldn't ignore.

A complete guide to the 12 health screenings every man over 40 needs — what they test for, when to get them, and what your numbers mean.

A targeted 10-minute daily exercise routine for men over 40 with lower back pain. Science-backed movements that reduce pain and build lasting spinal resilience.

Calculate your free testosterone from your blood test results using the clinically validated Vermeulen formula. Understand what the number means for men over 40.

Learn how to get your testosterone levels checked: which tests to order, how to prepare for the blood draw, normal ranges for men over 40, and what low results mean.

Evidence-based natural treatment options for enlarged prostate (BPH) in men over 40, including supplements, diet changes, and lifestyle strategies backed by clinical research.

Does masturbation cause erectile dysfunction? Can porn rewire your brain? A research-backed guide to ED, solo habits, and sexual health for men over 40.

A minimalist, evidence-based skincare routine for men over 40: 2 steps morning, 2 steps evening. Specific product recommendations backed by dermatology research.
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