Educational

Bathroom scale, body-fat illustration, and a glass of water with a circular chart.

What Body-Fat Tests Measure?

Body-fat tests estimate body composition from different physical measurements, so results depend on the method and testing conditions.

Heart and lungs beside a segmented circle and flowing colored bands.

Stopped Training? What Happens to Your Fitness?

Detraining can reverse exercise adaptations when training stops or falls, but different fitness qualities decline at different rates.

Illustration of a bicycle wheel, liver, running shoe, and water symbols representing endurance fueling and hydration.

Road Worlds and Berlin Marathon: Why Endurance Fueling Changes with Exercise Demands

Endurance fueling matches carbohydrate and fluid intake to exercise demands, with a practiced plan that accounts for tolerance and recovery time.

Fat droplets passing through illustrated intestinal structures into transport particles.

How Dietary Fat Travels through Your Body

Dietary fat changes physical form during digestion and absorption so poorly water-soluble lipids can travel through the body’s watery fluids.

Heart beside a dumbbell and circles showing tissue patterns.

A Larger Heart Isn’t Always an Athlete’s Heart

Heart enlargement can reflect healthy training adaptations or disease, so a larger heart does not automatically mean an athlete’s heart.

Food and nutrient particles connected to a large illustrated cell.

How Your Body Manages Fuel between Meals

Fuel use shifts gradually between meals as nutrient supply and hormone signals change, moving metabolism from storage toward use of body reserves.

Bone, kidney, and digestive tract connected by flowing bands and mineral particles.

Why Blood Calcium Levels Do Not Reveal Your Calcium Intake

Blood calcium can stay normal even when dietary intake is inadequate because hormonal responses help protect the circulating calcium pool.

Mitochondrion between a moonlit plate of food and a steaming bowl.

What Train Low Means for Endurance Training?

Train-low strategies reduce carbohydrate availability for selected endurance sessions, but research has not established one consistently best approach.

Kettlebell and timer beside a pyramid of stacked weight plates.

What’s the Difference between Single Sets, Multiple Sets, and Pyramid Training?

Pyramid training changes load and repetition targets across multiple sets, while single-set and multi-set labels describe how many sets occur.

Bowls of sugars, corn, and fruit beneath an illustrated liver.

Which Is Worse: High-Fructose Corn Syrup or Other Sugars?

High-fructose corn syrup has not consistently caused greater weight gain than sucrose when calorie intake is comparable in controlled studies.

Mountain trail with sunshine, rain, a river, and a magnified contour map.

How to Adapt Your Workout to Outdoor Conditions

Outdoor exercise requires preparation for changing environmental demands, because the same workout can pose different risks across settings.

Plate of food beside a stomach illustration and a curved line.

Why Losing Appetite with Age Can Become a Nutrition Problem

Appetite loss in older adults can push food intake below energy needs, increasing the risk of unintended weight loss even as calorie needs decline.