Heart disease causes 45% of on-duty firefighter deaths in the US. Here is what the research says about first responder fitness, and how stair climbing helps you train for the job.

Not weak. Not undertrained. Switched off. If you spend 6 to 10 hours a day at a desk, your brain may have reduced its recruitment signals to your glutes through a process called reciprocal inhibition. Discover why heavy squats aren't fixing the issue and how a targeted pre-activation routine combined with loaded stair climbing can reactivate your glutes and protect your lower back.

The fat burning zone on every cardio machine traces back to a 1971 formula derived from 11 unpublished studies. Here's what it actually means, and what burns fat instead.