|
|
|
|
|
<br>Fartlek - Literally, "speed play" in Swedish. It refers to interval workouts of combined depth, i.e. a mix of quick and sluggish operating. Fast-twitch - Type of muscle fiber which contracts rapidly and powerfully but fatigues shortly. Fatigue - A feeling of weakness or [Healthy Flow Blood](https://www.kenpoguy.com/phasickombatives/viewtopic.php?id=5491926) exhaustion |