Caffeine can improve alertness, focus, and training performance.  It is one of the most widely used performance aids in the world. But caffeine also affect...

When people think about recovery, they usually think about sleep, training load, or mental stress. But there’s another major system that can influence HR...

Metabolic flexibility is your body’s ability to efficiently switch between fuel sources — primarily fats and carbohydrates — depending on what the situation...

Supplements can help around the edges. But they don’t override poor sleep, excessive training load, or chronic stress. Some nutrients and compounds may su...

You’ve may have heard people say things like: “I’m too sympathetic.” “I need to be more parasympathetic.” It sounds like one is good and the other is bad. ...

Most people think of stress as physical or emotional. But one of the most consistent modern stressors is something we barely notice anymore: constant digit...

Not all fatigue comes from your muscles. Sometimes your legs feel okay, your soreness is low — yet your energy is flat, motivation is low, and HRV is suppr...

Not all training stress comes from muscles and heart rate. Some sessions are physically moderate but mentally demanding — like learning a new lift, practic...

Breathing is automatic — but how you breathe during exercise affects how stressful that session is to your nervous system. Two people can do the same worko...

Easy aerobic training is supposed to support recovery, build aerobic capacity, and improve nervous system balance. But how you breathe during that traini...