Blog
Insights, tutorials, and updates from the Bodly team. Learn better body tracking, sustainable habits, and practical ways to measure progress.
How Many Calories Should I Eat a Day? Chart by Age and Sex
How many calories you need a day, from the US Dietary Guidelines table by age, sex and activity, how to personalise it, what a realistic deficit does to your weight, and what Apple Watch says people burn.
Signs of Overtraining: Symptoms, Causes and Recovery Time
The signs of overtraining according to sports medicine's joint consensus, how long recovery takes at each stage, what HRV and resting heart rate can and cannot tell you, and how to prevent it.
How Much Deep Sleep Do You Need? Normal Amounts by Age
How much deep sleep is normal: sleep-lab values by age, what Apple Watch owners actually see (and why trackers undercount it), and the evidence on how to get more.
Zone 2 Heart Rate by Age: Chart, Calculator and How to Train
Your zone 2 heart rate by age, with both common max heart rate formulas, why apps give different numbers, how to set zones on Apple Watch, and how much zone 2 people actually get.
WHOOP vs Fitbit (2026): Fitbit Air, Accuracy and Cost
WHOOP vs Fitbit, now that the $99.99 Fitbit Air is a screenless band too: Recovery vs Readiness, what the accuracy evidence says, battery, subscriptions and the cost over two years.
Fitbit vs Apple Watch (2026): Sleep, Readiness and Price
Fitbit vs Apple Watch compared on what matters for health: sleep accuracy in a 2024 sleep-lab study, readiness scores, battery life, the Google Health subscription and price.
Is the Oura Ring Worth It in 2026? Cost and Membership
Is the Oura Ring worth it? The real cost with the membership over two and three years, what you lose without it, what three studies found on accuracy, and who should skip it.
Is WHOOP Worth It in 2026? What You Get for the Money
Is WHOOP worth it? What the membership costs per day, what three validation studies found, who gets real value from it, and when the Apple Watch you already own does the same job.
The Best Apple Watch Apps in 2026, by Category
The best Apple Watch apps for health, sleep, running, the gym and everyday life, each checked on the App Store for a real watch app and its current price, plus the built-in apps worth using.
WHOOP vs Oura (2026): Two Studies, Scores and Cost
WHOOP vs Oura Ring compared: what two independent studies found when both were worn at once, how Recovery maps to Readiness, battery, and the real cost over two years.
Oura vs Apple Watch (2026): Sleep, Accuracy and Cost
Oura Ring vs Apple Watch compared: sleep-lab and ECG accuracy, readiness and sleep scores, battery, how often Apple Watch owners really track sleep, and the cost over two years.
WHOOP vs Apple Watch (2026): Accuracy, Recovery and Cost
WHOOP vs Apple Watch compared: what a sleep-lab study found when both were worn at once, how WHOOP's scores map to Apple's, battery and real sleep-tracking data, and the cost over two years.
Apple Watch Readiness Score Explained (watchOS 27)
What Apple Watch's new Readiness score means, the 0 to 10 bands, what goes into it, which watches have it, why yours may not show, and how to get a recovery score on older models.
Apple Watch vs Garmin (2026): Health, Recovery and Battery
Apple Watch vs Garmin for health and recovery: Body Battery and Training Readiness against Apple's Vitals and Readiness, sleep-lab accuracy, battery life and price.
7 Best Calorie Tracker Apps in 2026 (Free Plans and Prices)
The best calorie tracker apps compared: which ones are free, what the paid plans cost, how accurate their food databases and photo scanners really are, and which logging method suits you.
Best HRV Apps in 2026: Watch, Camera or Chest Strap
The best HRV apps for iPhone compared by how they measure heart rate variability (Apple Watch, phone camera or chest strap), what they cost, and how accurate each method is.
WHOOP vs Garmin (2026): Accuracy, Recovery and Cost
WHOOP vs Garmin compared: how Recovery maps to Body Battery and Training Readiness, what a sleep-lab study found on accuracy, battery life, and what each costs over two years.
Apple Watch Sleep Score: How It Works and What's a Good Score
How Apple Watch calculates your Sleep Score (duration 50, bedtime 30, interruptions 20), what each range means, why it can feel too generous, and how to raise each part.
What Is HRV? Heart Rate Variability Explained Simply
HRV is the tiny variation in time between heartbeats. What it measures, RMSSD vs SDNN, what's normal for your age, what lowers and raises it, and how to measure it.
Resting Heart Rate by Age: Chart for Men & Women
What is a normal resting heart rate for your age and sex? Percentile charts from 14,000 healthy adults, what counts as good, when to see a doctor, and how to lower yours.
Apple Watch HRV: What's Normal and How Accurate?
What a normal Apple Watch HRV looks like (with data from 61 users), how the watch measures it, why it reads lower than WHOOP or Oura, how accurate it is and how to use your trend.
Apple Watch Resting Heart Rate: Average, Normal, Accurate?
How Apple Watch measures resting heart rate, how accurate it is, what a normal number looks like, why yours goes up or down, and how to read the trend.
Best Apple Watch Recovery Apps in 2026: 5 Compared
Athlytic, Bevel, Gentler Streak, Training Today and Bodly compared: free tiers, prices, HRV and recovery scores, and which Apple Watch recovery app fits you.
Best Cal AI Alternatives in 2026 (Free Options)
The best Cal AI alternatives for AI photo calorie counting, including free options, plus what research says about how accurate AI calorie counters really are.
Best Noom Alternatives in 2026 (Free & Cheaper)
The best free and cheaper Noom alternatives for calorie tracking, habit change and weight loss, and what each one replaces from Noom.
Best Oura Ring Alternatives in 2026 (No Subscription)
The best Oura Ring alternatives, including smart rings with no subscription and the no-new-hardware option: getting readiness, sleep and recovery scores from the Apple Watch you already own.
Best Sleep Tracker Apps in 2026 (iPhone & Apple Watch)
The best sleep tracker apps for iPhone and Apple Watch compared, from Apple's free Sleep Score to AutoSleep, Sleep Cycle and Bodly, with and without a watch.
Bevel App Review 2026: Is It Free & Worth It?
What Bevel does well, what is free, what Bevel Pro costs, how it compares to WHOOP, and when a different Apple Watch app is the better fit.
Does Apple Watch Track Stress? What It Can and Can't Do
Whether Apple Watch has a stress score, what it measures that reflects stress (HRV, heart rate, State of Mind), and how to get a daily stress reading from your watch.
GLP-1 Weight Loss Results by Month: What Trials Show
How much weight people lose on Wegovy, Zepbound, Mounjaro and retatrutide month by month and per week, according to the clinical trials, and how to track your own results.
Heart Rate Recovery Chart by Age: Good Numbers Explained
What heart rate recovery is, what a good one-minute number looks like, how age changes it, how Apple Watch measures Cardio Recovery, and how to improve yours.
Metabolic Adaptation: Why Weight Loss Slows Down
What metabolic adaptation is, how much it really slows your metabolism, why weight loss plateaus, and what actually helps, based on the research rather than diet myths.
Normal Sleeping Respiratory Rate & Blood Oxygen Explained
What a normal respiratory rate and blood oxygen level look like while you sleep, what Apple Watch Vitals shows, and which changes are worth talking to a doctor about.
Welltory Review 2026: Is It Free & Worth It?
What Welltory measures, what the free version really includes, what Premium costs, and when an automatic Apple Watch recovery app is the better fit.
What Is GLP-1? How the Hormone and GLP-1 Drugs Work
What GLP-1 is, what the hormone does in your body, how GLP-1 medications like Ozempic, Wegovy, Mounjaro and Zepbound work, their common side effects, and what to track if you take one.
Whoosh Effect Weight Loss: Is It Real?
What the whoosh effect is, why the scale can stall for weeks and then drop overnight, what science actually says about it, and how to stop the scale from messing with your head.
Why Does GLP-1 Cause Muscle Loss and How to Prevent It
Why Ozempic, Wegovy, Zepbound and Mounjaro can cause muscle loss, how much of the weight lost is lean mass in the trials, and how to protect your muscle and track fat loss.
Yazio vs MyFitnessPal (2026): Which Is Better?
Yazio and MyFitnessPal compared on free features, barcode scanning, food databases, fasting, prices and Apple Watch, plus which one fits which goal.
How Accurate Is Apple Watch Calorie Tracking? (What the Research Says)
Apple Watch measures heart rate within a few percent and calories within about 20-40%. Here's why the gap is so large, which activities it gets most wrong, how to calibrate it, and how to use the number without wrecking your deficit.
Garmin Body Battery Explained (And How to Get It on Apple Watch)
What Body Battery actually measures, how Garmin calculates it from HRV, stress and sleep, what a normal range looks like, why yours never hits 100 - and how to get the same energy score from an Apple Watch.
How to Improve HRV: What Actually Works, Ranked
Most HRV advice is a list of twenty things with no sense of which matter. Here they are ranked by effect size and time-to-effect, plus the troubleshooting order for a low HRV and how long to wait before judging a change.
How to Take Body Measurements (Correctly) for Weight Loss & Muscle Gain
Where to put the tape, how tight to pull it, which sites actually matter for men and women, how often to remeasure, and how to read the numbers so a 1 cm change means something.
Low Cardio Fitness on Apple Watch: VO2 Max Meaning and How to Fix It
Got a 'Low Cardio Fitness' notification from your Apple Watch? Here's exactly what the number is, why it's usually lower than reality, the five setup mistakes that fake a low score, and the training that actually raises it.
Why Am I Gaining Weight in a Calorie Deficit?
If you are in a calorie deficit but gaining weight, water retention, tracking errors, digestion, training stress, or a short time window may be hiding fat loss.
Losing Inches but Not Weight: Why the Scale Is Not Moving
If your measurements are going down but your scale weight is stuck, you may be losing fat, gaining muscle, holding water, or seeing normal weight noise.
What Is Body Recomposition? Lose Fat and Build Muscle
Body recomposition means losing fat and gaining muscle at the same time. Learn how it works, who it suits, and how to track progress beyond the scale.
Good HRV by Age: What's Normal & Is Yours Healthy?
A good HRV depends on your age, sex, and fitness - not a universal number. Use the age chart, the percentile method, and a 3-step check to see if your heart rate variability is healthy for you.
Lose It vs MyFitnessPal vs Cronometer (2026)
Compare Lose It, MyFitnessPal, Cronometer, and Bodly for calories, macros, weight tracking, measurements, progress photos, and recovery-style health metrics.
Best WHOOP Alternatives in 2026
Compare the best WHOOP alternatives for sleep, recovery, readiness, training, stress tracking, and broader health progress.
5 Ways to Stay Motivated on Your Fitness Journey
Stay motivated on your fitness journey with specific goals, visual tracking, community support, and habit-building strategies for lasting success.
10 Tips for Effective Body Tracking with Bodly
Ten practical tips to track weight, measurements, progress photos and meals so your data tells the truth, plus real data on what tracking habits work.
Transform Your Health: Benefits of Regular Tracking
Regularly tracking your health metrics transforms vague goals into measurable milestones, providing clarity and motivation for better results.
Best Free MyFitnessPal Alternatives (2026)
Compare the best free MyFitnessPal alternatives for calorie tracking, macros, barcode logging, weight trends, measurements, recovery, and progress photos.
How to Measure Body Fat in 2026: A Complete Guide
Compare DEXA, Bod Pod, BIA scales, skinfold calipers, tape measurements, and progress photos so you can measure body fat more consistently.
Why Bodly Is The Best Body Tracking App in 2026
See why Bodly is a strong body tracking app if you want calories, measurements, weight, progress photos, and recovery-style metrics in one place.
7 Best Free Weight Tracker Apps for Weight Loss (2026, Tested)
Compare the best free weight and weight loss tracker apps for daily weigh-ins, trend smoothing, calorie logging, body measurements, progress photos, and full-body progress tracking.