If running through the woods or shredding the singletracks on your mountain bike are what you're into, the Mens Gravity Trail Jacket from Jack Wolfskin is exactly the right jacket for you. This stretchy fleece jacket ensures superb climate comfort, even when you work up a sweat. The breathable, fast drying fabric takes care of that. Mesh inserts on the back and under the arms ramp up the ventilation performance. With a very windproof (and water resistant) fabric to the front of the jacket to combat wind chill, it also gives you factor 50+ UV protection and is equipped with reflectors for better visibility when you're out after dark. It even has a special loop for your headphones so you can listen to your fave tunes when you're on the move.