Under extreme metabolic conditions, like a marathon, the brain may turn to cellular fat stores to maintain function, according to a new study.

BUYING GUIDEThese are the best running watches in every category, from Garmin Fenix 8 to Apple Watch Series 8 and Coros Pace 2.

ReferencesRowing machines and treadmills do not challenge your cardiovascular system in the same way, so what is the science behind it?

Buying GuideBring movement into your work day: Get your steps in while at work with these under desk treadmill deals.

Buying guideFrom Under Armour Infinity High to Lululemon Enlite, these are the sports bras we recommend.

It's the start of your spring marathon training, and here is everything you need, from the best running shoes to a home treadmill

BUYING GUIDEUnleash the music — these top wireless and compact options will help you step up your workouts.

REFERENCEDiscover the mental health benefits of exercise here, with everything you need to know.

By digitally modeling muscles and tendons for the skeleton of Lucy (Australopithecus afarensis), researchers determined that our hominin ancestors could run well but topped out around 11 mph.

Experts tell Live Science what it means to "hit the wall" while exercising and how to avoid it.