Kovr · Training Science
HRV, recovery, nutrition, and the data behind better performance. Evidence-based. No fluff.
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How to Actually Understand Your Garmin Data (Not Just Collect It)
You've got years of HRV, sleep, training load and VO₂max — but a watch collects data, it doesn't explain it. How to turn the numbers into a plain-English why, and choose an app that reads what you already have.
Training
Cardiac Drift: Why Your Heart Rate Climbs on Easy Runs
You start an easy run at 135bpm and drift to 155 at the same pace — without slowing, without losing fitness. That's cardiac drift. What causes it, when it's normal, when it's a flag, and the simple test that turns it into a fitness marker.
Training
Why Every Race Predictor Gives You a Different Time (And How to Use One)
Garmin says 3:51. Coros says 4:13. Apple's VO₂max disagrees with both. Why every device measures differently, how accurate the estimates really are — and the variable none of them price in: the weather you'll actually race in.
Training
Your Plan and Your Tracker Describe the Run. Nothing Describes You.
Your plan tells you what to run. Strava logs what you did. Both describe the session — neither reads the body that absorbed it, which changes every morning. The missing layer in your training stack, and why it isn't another tracker.
Training
Lost Fitness, or Just the Weather? How to Tell the Difference
You ran slower than last week and the worry creeps in — but a single slow run is rarely fitness loss. Here's how to separate heat and humidity from genuine decline, using heart rate against pace, HRV trends, and the difference a hot morning really makes.
Nutrition
Carb Loading for a Half Marathon: How Much You Actually Need (and When to Skip It)
Most half-marathoners either overload and feel heavy or undereat and hit the wall. The evidence-based number is 8–10g of carbs per kg across a single day — when it helps, when to skip it, and the mistakes that backfire.
Training
What Each Wearable Writes to Apple Health: Garmin, Apple Watch, Oura & WHOOP Compared
They all sync to Apple Health — but not the same things. Exactly which workouts, active energy, HRV and sleep each device writes to HealthKit, the catches that leave data missing, and what it means for any app reading your health data.
Training
Garmin Training Readiness Explained: What Your Score Actually Means (and Where It Falls Short)
Garmin gives you a single 0–100 readiness score every morning, built from six hidden-weighted factors. Here's what each band means, how to fix a low score, the difference from Training Status, and the one thing the number can't tell you.
Recovery
How Much Sleep Do Runners Need? What the Research Says (and Why Most Runners Don't Get Enough)
A 2025 study of 425 recreational runners found those sleeping under 7 hours had a 68% likelihood of injury within 12 months — 1.78× the risk of well-rested runners. Here's how much sleep your training is actually asking for.
Nutrition
How to Fuel a Long Run: What the Research Actually Says (and Where Most Runners Get It Wrong)
A 2025 study tracked sixty endurance athletes through real races. Marathoners ate just 21.7g of carbs per hour. The target is 60–90g. Here’s why the gap exists — and the four-week protocol that closes it.
Recovery
Why Do I Feel Exhausted After an Easy Run? Four Causes the Data Reveals
Feel wiped out after what should have been an easy run? Almost always it’s one of four specific causes — and once you know which, the fix is obvious.
Training
HRV for Runners: What Your Heart Rate Variability Actually Means for Training
Your Garmin has a number. Your Oura has a score. Your Apple Watch has a colour. Here’s what they’re all actually measuring — and how to make better training decisions with it.
Training
Am I Overtraining? The Signs Runners Miss Until It’s Too Late
More than 60% of serious runners will experience overtraining at least once. Here are the early signals — and why HRV catches them days before you feel it.
Nutrition
How Many Carbs Do Runners Need Per Day? (The Numbers Most Runners Don’t Know)
Most recreational runners eat like sedentary people but train like athletes. Here are the actual targets — and how to hit them without weighing everything you eat.
Nutrition
How Much Protein Do Runners Actually Need? (Most Athletes Underestimate This)
The target for endurance athletes is nearly double the general population recommendation. Here are the numbers, the timing, and the best value food sources.
Training
Why Was My Run So Hard Today? HRV, Glycogen, Heat or Load — Which One Was It
Bad runs feel mysterious from the inside. They’re not. Here’s how to diagnose the cause — and what to do about it tonight.
Recovery
How Alcohol Affects Running Performance and HRV (Data From 600,000 Athletes)
Oura data from 600,000 members. WHOOP research. Eight Sleep’s 2,600-night study. Here’s what the numbers show — and how to see your own pattern.
Recovery
How Many Rest Days After a Long Run? What HRV Data Says vs What Coaches Recommend
Feeling better isn’t the same as being recovered. Here’s what the cellular damage data says — and the HRV signal that tells you when to return.
Training
Training Fatigue vs Fitness Loss: Why You Feel Slower Despite More Training
Feeling slow doesn’t mean you’re losing fitness. Here’s the 30-year-old model that explains why — and how to read the difference in your own data.
Training
Marathon Training Burnout: How to Spot It in Your HRV Before You Feel It
The burnout trajectory is visible in your data weeks before you feel it. Here’s how to read the signal — and what to do when you see it.
Nutrition
Cheapest Carbs for Runners: Best Value Fuel Sources (Rice, Oats, Pasta Ranked)
Marathon runners need 490–700g of carbohydrates per day. Here are the five staples that cover it — ranked by value per gram of carbohydrate.
Cycling
HRV Training for Cyclists: Why Your Ride Feels Hard After a Run Day
A 2025 study on 28 experienced cyclists found HRV-guided training improved FTP and maximal power output. Here’s what that means for how you plan your week.
Swimming
Swimming and HRV: How Long Does It Take to Recover From a Hard Swim Session?
Research shows HRV drops consistently after 3–5 days of high swim volume. Here’s how to use that signal — and why it matters especially if you also run or ride.
Nutrition
Should Endurance Athletes Take Creatine? Dosing, Timing & the Weight Gain Question
The weight gain question answered, the right dose for runners, cyclists, and triathletes, and why the offseason is the window that matters.
Cross-Training
Reformer Pilates for Runners and Cyclists: HRV, Recovery and Why Your Spine Needs It
Reformer Pilates produces parasympathetic HRV improvement post-session. For cyclists it decompresses the spine and restores hip flexors the bike shortens. Here’s the science and how to fit it in.
Training
Strength Training for Runners: HRV, Sequencing and the Running Economy Gains
A 2025 randomised trial found 10 weeks of heavy strength training twice weekly produced significant running economy gains. Here’s the HRV suppression timeline and sequencing rules.