Platypus Big Zip Water Reservoir

Hydration is important when you’re engaged in strenuous activities, particularly while outdoors on a hot day. Whether you’re cycling to work, hiking or indulging in some other type of sporting activity, keeping fluids in your system is essential. Without it, you could start suffering from dehydration, which can include a drop in energy, headaches and dizziness. If left unchecked, dehydration can even cause fainting.

But dragging along enough water to last for hours can be tough, especially if you’re trying to keep your load light. Hydration systems are designed to make it easy to stay hydrated without having to deal with water bottles. A hydration backpack affixes to your body to keep your hands free, so you can focus on the day’s activities. You’ll drink through a tube that serves as a giant, flexible, leakproof straw.

Before you start shopping, consider whether you want an all-in-one hydration backpack or a separate water bladder that you can slide into whatever pack you’re carrying. You can save money and get more versatility from a hydration bladder, but you’ll need to consider how you’ll attach it to your body or bicycle to keep your hands free.

The type of activity you’re doing will also affect which hydration pack you choose. “Many manufacturers have tailored the design of their packs in terms of weight distribution, the location of straps and its profile to your body’s movement,” says our home goods expert Vicki Liston. “Cycling systems, for example, will fit differently on your body than a running or hiking system.”

Since most hydration packs feature similar water capacity, pay close attention to the weight and size of the model you choose so that you can keep your load as light as possible while you’re out and about.

As for the bladder itself, there are plenty of features to consider before you buy. You’ll want a hydration system that doesn’t leak, as well as one that insulates the liquids inside to keep them cool as long as possible. That means the tube that runs from the bag to your mouth should also be insulated to keep the liquid cool as it moves through.

The opening on some hydration systems is small, which will keep you from being able to insert ice cubes or get in to clean it. Look for one that allows for this if you plan to use ice, or you’re concerned about keeping it clean. You’ll be glad, in the end, that you chose one that makes clean-up easy.

Lastly, there’s safety as a consideration. Some consumers prefer to steer clear of materials made with BPA, so you’ll want to search for one that promises to be BPA free if this is important to you. Some hydration bladders are also antibacterial, which will help protect against mold forming, even if you accidentally leave liquid in the pack for days at a time.

• As you start shopping, you’ll notice multiple options when it comes to the design of your hydration pack. Backpack-based designs build the hydration pack into a padded garment that you wear like a vest or backpack. Then there are freestanding hydration packs that you can slip into an existing backpack or bag.
• If you opt for the backpack design, make sure you choose a model that’s comfortable. For example, a pack that is built with padded shoulder straps is a great choice, as is a model with adjustable straps.
• Ventilation is also important if you’ll wear your backpack outdoors in hot weather. Consider a pack made from a breathable mesh that promotes airflow as you move, keeping you cool whether you’re bicycling around town or hiking your favorite trail.
• It’s also important to look for a hydration pack with an easy-to-use on/off valve for when you’re ready to drink. With some models, you simply pull the valve out to use, then push it back in to lock it in place until it’s time to hydrate again.
• Leaks are no fun, especially with hydration bladders that are designed to go into an existing backpack or bag. They are made to keep liquids inside the bag when you aren’t drinking. Some models use a click connection that keeps leaks at bay much better than traditional screw designs.
• Over hours of wear, a hydration pack can weigh you down, so you’ll find you benefit from not choosing a pack that adds weight to the water you’re carrying. The Sojourner Rave Water Bladder 2 Pocket Hydration Pack weighs only 13 ounces, putting it among the most lightweight you’ll find. Other bladders and packs weigh much more. Of course, size also matters. Packs that are very small in size won’t take up much room on your back.
• You won’t want to worry about your hydration pack breaking when you’re far from home. Fortunately, many water packs are built to last. Look for a hydration bladder that is both pressure- and wear-resistant, as this type offers many years of use.
• Science has come up with all kinds of ways to keep liquids cool for hours using insulation. But with hydration packs, you’re not only dealing with the bag storing that liquid, but also the tube through which you drink. Go with a pack that insulates its tube.
• The openings on some hydration packs make it tough to insert ice. Look for a large opening that makes getting ice inside easy. Another benefit of a large opening is that it lets you easily insert cleaning brushes inside to keep it clean.
• Some hydration packs require you to fully remove the bladder from its pack before you can refill it.
• Consumers are increasingly looking for materials that don’t contain bisphenol A (BPA), a chemical being reviewed by the FDA for its safety. BPA is found in cans and certain plastics. If you’re concerned about BPA, the Sojourner Rave Water Bladder 2 Pocket Hydration Pack is made from BPA-free material.
• Safe or not, bags that leave an aftertaste make hydration difficult. Look for a hydration bladder that doesn’t have that chemical taste that can be especially noticeable when drinking water. The material in the bladder is may also antibacterial — a helpful feature to have in a product that will be exposed to moisture for hours at a time.
• “Look for a hydration system that’s easy to clean,” says Liston. “The bladder, drink tube and mouthpiece will be teeming with bacteria if you don’t thoroughly clean,  sterilize and allow it to dry. If it’s hard to get inside the bladder, you’re probably going to miss some spots and the growth will begin.”
• If you’re hitting the trails for the day, you’ll want a pack that can hold enough water to get you through. The Sojourner Rave Water Bladder 2 Pocket Hydration Pack holds 2 liters of water, which compares to the amount of liquid you get in a large bottle of soda.
• Pockets can be helpful no matter where you’re wearing your hydration pack. Some models offer three storage compartments, handy for storing your keys, money, glasses and other items.
• For those on a budget, most hydration packs are priced reasonably. However, it’s important to keep in mind what you’re getting for your money. Hydration bladders without backpacks all you to save significantly over competitors, but keep in mind you’ll need a bag to carry it in, which is an extra expense.