Conventional wisdom states that you improve the skills you practice. Recent research has added credibility to cross training. (See 8 Surprising Ways Pro Athletes Cross-Train.) An often overlooked way to cross-train is hiking.

Did you know that hiking can help you improve your running economy (i.e., the amount of oxygen your body uses during a run). Hiking also promotes athletic development (without impact), because it engages the hips, quadriceps, core and upper body. But one of the greatest benefits of hiking is the high-calorie expenditure it promotes. You can burn as many (or more) calories as you do running.

However, you need to stay hydrated while hiking the trails. Before you begin, you may want to look into getting a hydration backpack. They’re designed for the active lifestyle and they look great as well. Here are my top three hydration backpack recommendations:

Camelbak Lobo 100-ounce Pack

This Camelbak hydration pack carries up to 100 ounces of water in a specially designed reservoir with a convenient drinking tube. The reservoir is housed in a spacious backpack (200 cubic inches of space), large enough to hold a cell phone, energy bars and other essential items. The gel-filled shoulder pads, sliding sternum strap and removable waist belt make long hikes or bike rides extremely comfortable. This product received 4.8 stars out of 5 from shoppers on Amazon.com.

Camelbak Rogue 70-ounce Pack

If you need a lighter backpack with just enough carrying capacity to get you through the day, consider the Rogue hydration pack from Camelbak. It features a 70-ounce reservoir and a 200-cubic inch bag. The air mesh harness and air channel feature keep you cool without adding weight. This is a great hydration pack for cyclists. It received great customer reviews on Amazon.com: 4.7 stars out of 5.

Osprey Manta 25 Daypack

Day hikers and adventure racers should consider this day pack from Osprey. It features a 100-ounce Hydraform reservoir and a 180-degree, on-off pivot bite valve. Unlike other hydration backpacks, this one features two pockets and a magnetic sternum strap, as well as a key clip and integrated rain cover. Customer reviews at Amazon.com are positive, averaging 4.7 stars out of 5.