Understand the numbers of your body

Where the ranges CatLena shows come from, what each one means and which studies are behind them.

• Weight

  BMI: what it measures and what it does not

  How body mass index is calculated, the WHO ranges and the disease risk linked to each one.

• Body fat

  Body fat percentage: ranges by sex and age

  Where the Very low, Healthy, High and Very high ranges come from, and why they change with sex and age.

• Composition

  Body composition: where your weight comes from

  Why BMI and body fat together say more than each one alone, and where the limits are: essential fat and natural lean mass.

• Fitness

  VO₂ max: the size of your aerobic engine

  What VO₂ max is, how to compare yours with people of the same sex and age, what it says about health and the equivalent 5 km time.

• Sleep

  Sleep: how many hours a night and what it does to training and fat loss

  Why adults need at least 7 hours, what short sleep does to fat loss, hunger, muscle and performance, and how to read the CatLena sleep scale.

• Training

  Workout calories: how CatLena estimates runs and strength

  How CatLena estimates the calories of a run (weight × km) and a strength workout (MET × weight × time), with examples and the studies behind them.

• Energy

  Stamina: how CatLena estimates your glycogen

  What glycogen is, how much your body can store and how CatLena estimates the store day by day, with the studies behind it and worked examples.

• Weight loss

  How to lose weight: losing fat without losing muscle

  Calorie deficit, rate of loss, protein, strength training, surplus and sleep: what studies show about losing fat and how CatLena does the math.