Corpus is an iPhone physique progress tracker that turns guided photo check-ins into estimated body-composition trends, muscle-group progress, and guidance grounded in your history.https://getcorpus.app/en-ushttps://getcorpus.app/blog/navy-body-fat-formula/https://getcorpus.app/blog/navy-body-fat-formula/The Navy formula estimates body fat from height, neck, waist and hips. Studies against DEXA found it reads about 4 to 6 points low and can miss weeks of fat loss.Tue, 13 Oct 2026 00:00:00 GMThttps://getcorpus.app/blog/resting-heart-rate-by-age/https://getcorpus.app/blog/resting-heart-rate-by-age/A resting heart rate by age chart from US survey and wearable data: kids fall from 129 to 78 bpm, adults average 65–72 bpm, and women run a few beats higher.Fri, 09 Oct 2026 00:00:00 GMThttps://getcorpus.app/blog/spren-vs-corpus/https://getcorpus.app/blog/spren-vs-corpus/What the Spren app costs on the US App Store, what its accuracy claims rest on, and how it compares with Corpus for weekly body-fat tracking. Disclosed comparison.Tue, 06 Oct 2026 00:00:00 GMThttps://getcorpus.app/blog/dexa-scan-alternatives/https://getcorpus.app/blog/dexa-scan-alternatives/The DEXA scan alternatives worth using are the ones you can repeat: smart scales, calipers, tape and photo apps. What studies show each gets right and wrong.Fri, 02 Oct 2026 00:00:00 GMThttps://getcorpus.app/blog/are-smart-scales-accurate/https://getcorpus.app/blog/are-smart-scales-accurate/Smart scales weigh you accurately but estimate body fat poorly. What studies comparing them with DEXA found, why hydration skews the number, and how to use one for a real trend.Mon, 14 Sep 2026 00:00:00 GMThttps://getcorpus.app/blog/best-body-composition-tracking-apps/https://getcorpus.app/blog/best-body-composition-tracking-apps/DEXA, smart scales, calipers, tape-measure equations, and photo-based apps like Corpus, Bodilab, and Spren — what each measures, what the evidence says, and which fits your goal. Written by the maker of Corpus, with that bias disclosed.Mon, 14 Sep 2026 00:00:00 GMThttps://getcorpus.app/blog/body-fat-percentage-chart/https://getcorpus.app/blog/body-fat-percentage-chart/Healthy body fat percentage ranges for men and women by age, from the study most charts are built on — plus what each range tends to look like, when abs show, and why charts disagree.Mon, 14 Sep 2026 00:00:00 GMThttps://getcorpus.app/blog/body-recomposition/https://getcorpus.app/blog/body-recomposition/Body recomposition means losing fat and gaining muscle at once. What the research says about who can do it, the training and nutrition that drive it, how long it takes, and how to tell it's working.Mon, 14 Sep 2026 00:00:00 GMThttps://getcorpus.app/blog/cutting-vs-bulking-vs-recomp/https://getcorpus.app/blog/cutting-vs-bulking-vs-recomp/Should you cut, bulk, or recomp? The evidence-based rates for each phase, a simple way to choose based on body fat and training experience, and how to track whether it's working.Mon, 14 Sep 2026 00:00:00 GMThttps://getcorpus.app/blog/gaining-muscle-or-fat/https://getcorpus.app/blog/gaining-muscle-or-fat/The scale can't tell muscle from fat. Here are the signals that can — waist vs. weight, strength, photos, and composition trends — and why the first few weeks of training can fool you.Mon, 14 Sep 2026 00:00:00 GMThttps://getcorpus.app/blog/how-much-muscle-can-you-gain-naturally/https://getcorpus.app/blog/how-much-muscle-can-you-gain-naturally/An honest answer to 'how much muscle can I gain in a month?' — what the research can and can't say, the FFMI data behind 'natural limits,' realistic rates of weight gain, and how to see slow progress.Mon, 14 Sep 2026 00:00:00 GMThttps://getcorpus.app/blog/losing-inches-not-weight/https://getcorpus.app/blog/losing-inches-not-weight/Your waist is shrinking but the scale won't move. The usual explanations — recomposition, water, glycogen, and weekly weight rhythms — and how to tell which one applies to you.Mon, 14 Sep 2026 00:00:00 GMThttps://getcorpus.app/blog/skinny-fat/https://getcorpus.app/blog/skinny-fat/Skinny fat means a normal weight with relatively high body fat and little muscle. What the research calls it, why BMI misses it, how to measure it, and what usually works.Mon, 14 Sep 2026 00:00:00 GMThttps://getcorpus.app/blog/when-to-deload/https://getcorpus.app/blog/when-to-deload/Deloads exist to prevent overreaching before it happens, not to fix it after it does. Here's how to recognize the signs and what a useful deload week actually looks like.Thu, 03 Sep 2026 00:00:00 GMThttps://getcorpus.app/blog/hrv-apple-watch-explained/https://getcorpus.app/blog/hrv-apple-watch-explained/How Apple Watch measures HRV, how accurate it actually is compared to lab equipment, and what to do with the number once you have it.Tue, 01 Sep 2026 00:00:00 GMThttps://getcorpus.app/blog/how-often-to-measure-body-composition/https://getcorpus.app/blog/how-often-to-measure-body-composition/Daily, weekly, or monthly? Different signals, weight, photos, body fat trend, FFMI, are useful at different frequencies. Here's a practical cadence for each.Tue, 25 Aug 2026 00:00:00 GMThttps://getcorpus.app/blog/comparable-progress-photos/https://getcorpus.app/blog/comparable-progress-photos/Progress photos only work if two shots are actually comparable. Here's the practical setup, lighting, distance, pose, and timing, that removes the variables that aren't your actual progress.Tue, 18 Aug 2026 00:00:00 GMThttps://getcorpus.app/blog/body-fat-measurement-methods-compared/https://getcorpus.app/blog/body-fat-measurement-methods-compared/A straight comparison of the four common ways to estimate body fat percentage, DEXA, skinfold calipers, bioelectrical impedance, and photo-based estimates, and what each one actually gets wrong.Tue, 11 Aug 2026 00:00:00 GMThttps://getcorpus.app/blog/body-fat-percentage-photos/https://getcorpus.app/blog/body-fat-percentage-photos/Body fat percentage numbers mean little without a visual reference. Here's what the common ranges actually tend to look like, and why the same number can look different on different people.Tue, 04 Aug 2026 00:00:00 GMThttps://getcorpus.app/blog/hrv-sleep-training-load/https://getcorpus.app/blog/hrv-sleep-training-load/HRV can add useful recovery context, but it is not a green or red light by itself. Learn how to read a personal baseline alongside sleep and training load.Tue, 07 Jul 2026 00:00:00 GMThttps://getcorpus.app/blog/why-the-scale-lies/https://getcorpus.app/blog/why-the-scale-lies/Daily weight includes water, food, glycogen, and more. Learn how to read the trend without mistaking a normal fluctuation for lost progress.Tue, 16 Jun 2026 00:00:00 GMThttps://getcorpus.app/blog/what-is-ffmi/https://getcorpus.app/blog/what-is-ffmi/Understand Fat-Free Mass Index, how to calculate it, why body-fat estimates affect it, and how to use an FFMI trend with appropriate caution.Tue, 02 Jun 2026 00:00:00 GMT