Health7 min
Pregnancy calendar week by week — a guide
The three trimesters of pregnancy week by week: your baby’s development, changes in mum’s body and key tests. A practical calendar from week 1 to 40.
Blog — page 13
Health6 min
Fertile days and ovulation — how to calculate them
How to work out your fertile days and ovulation date from your cycle length. We explain the fertile window, the luteal phase and show a worked example.
Health6 min
BMI for children — percentile charts and norms
Why a child’s BMI is read from percentile charts rather than fixed thresholds. We explain percentiles, age norms and show an interpretation example.
Health6 min
Body fat — how to calculate the percentage
Methods for measuring body fat: calipers, BIA and the Deurenberg formula from BMI. We explain the percentage norms and show a worked example.
Health6 min
Blood pressure — norms and how to interpret them
What systolic and diastolic values mean, what the blood pressure norms are and when we talk about hypertension. A practical guide with a table of norms.
Health5 min
Menstrual cycle — how to count its length
How to correctly count the length of your menstrual cycle, what regularity means and when cycle length warrants a consultation. A guide with an example.
Sport6 min
VO2max — how to calculate it and what it says about fitness
What VO2max is, how to estimate it without a lab using your resting and maximum heart rate, and how to interpret the result. With a worked example.
Sport5 min
One-rep max (1RM) — how to calculate it without risk
How to estimate your one-rep max (1RM) using the Epley formula from the number of reps. We explain the formula, show an example and the safety rules.
Sport5 min
Water needs during training
How much water to drink before, during and after training. We explain how to estimate sweat losses and replace fluids and electrolytes. With an example.
Science7 min
The Doppler Effect Explained — Formula, Examples and Calculator
What is the Doppler effect, how does the frequency-shift formula work and where is it used? From ambulance sirens to astronomical red-shift and medical ultrasound.
Sport7 min
Training Volume Guide — How to Calculate Your Weekly Load
What is training volume, how do you calculate it and why does it determine your muscle growth? A practical guide to sets, reps, load and progressive overload for all levels.
Finance8 min
Baby First Year Costs in Poland 2026 — Complete Guide
How much does it cost to have a baby and survive the first year in Poland in 2026? A complete breakdown of birth costs, baby gear, monthly expenses, childcare and government benefits.