Explore Journal

How Your Muscles Help Keep You Warm

Skeletal muscles release heat as they use energy to contract, explaining why both deliberate exercise and involuntary shivering warm the body.

What Glycemic Index Says about Blood Sugar​​?

Glycemic index compares blood-sugar responses to equal amounts of carbohydrate, but cannot fully predict the effects of a usual meal.

How to Progress Plyometric Training

Plyometric progression should match the demands of each jump to the person’s control and capacity, rather than follow a universal ladder of difficulty.

How Iodine Supports Early Brain Development

Iodine supports thyroid hormone production during early development, when severe deficiency can cause lasting damage to the brain and nervous system.

How Aerobic Exercise Helps Your Body Use Oxygen

Aerobic training improves oxygen transport and use through changes across the cardiovascular system and muscles, rather than one adaptation alone.

Four Variables That Help Organize an Exercise Program

The FITT framework organizes exercise planning around four adjustable variables, helping match the training stimulus to individual goals.

Protein: Complete Doesn’t Always Mean High-Quality

Protein quality depends on the proportions of essential amino acids and their digestibility, beyond whether a food contains all nine.

How Your Muscles Sense Stretch and Tension

Muscle spindles sense changes in length while Golgi tendon organs track tension, providing feedback that helps the nervous system adjust movement.

Why Celiac Disease Is Different from a Food Allergy

Celiac disease causes gluten-triggered autoimmune damage to the small intestine, a different immune process from the reactions behind food allergy.

Why Some Muscle Fibers Are Built for Endurance and Others for Speed

Muscle fibers differ in contraction speed and energy supply, making some better suited to sustained effort and others to rapid, powerful work.

How to Structure a Flexibility Routine

A flexibility routine uses the FITT framework to organize stretching around useful movement goals, with technique and dose suited to the person.

What Does a Blood-Test Number Mean?

Blood-test results provide evidence about health, but a number’s meaning depends on the test and the circumstances surrounding the measurement.