Free 2-Day Shipping on Orders Over $50* — Limited Time Only
Take 10% Off Your Entire Order* »

Out of Stock

Item # OSM0004

Don't worry though, we have a lot more Hydration in stock than that.

View Similar Products
Item # OSM0004


Osmo's new PreLoad Hydration formula was developed specifically for use prior to hot events, time trials, and other high intensity workouts. PreLoad works to increase total body water and plasma volume, provides a buffer for lactic acid, and increases the cofactors needed for aerobic metabolism.

To break down exactly how PreLoad works, Dr. Stacy Sims, Osmo Nutrition's chief research officer, explains the processes that occur within the body during exercise. As you work out, body temperature rises due to the heat produced from working muscles. When body temperature rises above 102 degrees Fahrenheit, many of the body's systems are compromised, resulting in a steep drop in power output. For example, when athletes begin to feel thirsty, they are already at about a 2 percent body water loss, which can result in an 11 percent decrease in top end power.

To maintain proper function, the body works to regulate core temperature by moving blood to the skin and offloading heat through vasodilation and evaporative cooling -- also known as sweating. This system is effective, but requires continual replenishment. In hot environments, and during high intensity efforts, body water loss through respiration and perspiration can be so rapid that it becomes impossible to replace fluids fast enough to maintain optimal body water.

Fortunately, we can prepare by 'hyperhydrating' -- effectively going into an event with extra body water, or spare tank, keeping dehydration and the related performance losses at bay. This is where Osmo PreLoad Hydration comes in, as there are several primary actions PreLoad does to improve output levels. The initial thing Osmo does is increases blood plasma volume, which means that the total volume of blood circulating through the body is increased. This increased circulation reduces the compromise blood usually makes in hot conditions to go to the working muscles and to the surface to dissipate heat. With greater blood volume, both the metabolism of the muscles and heat dissipation at the skin surface can occur effectively.

Additionally, since athletes start their exercise in a hyperhydrated state, they have a greater amount of total body water to increase the effectiveness of the body's thermo-regulation system. This works to slow the rate of core temperature rise, which then slows fatigue and power decline. Because of this hyperhydration state the athlete starts in, PreLoad also stops cramping by increasing total body sodium stores, which eliminates the need to take on additional sodium during long duration events. Finally, PreLoad contains sodium citrate and sodium bicarbonate, both of which act as effective buffers. The citrate works to keep aerobic metabolism high, whereas the bicarbonate works to buffer lactic acid during the intense efforts.

Overall, PreLoad sets the body up by 'planning ahead' -- boosting sodium stores and plasma volume before exercise. This maximizes both thermo-regulation and overall output levels. For best results, Osmo recommends consuming PreLoad the night before and morning of an effort requiring maximum hydration and metabolic buffering.

The Osmo Nutrition PreLoad Hydration is available in one 20oz container and in the flavor Pineapple & Lemon.

  • Hyperhydration formula
  • Sodium citrate and sodium bicarbonate buffering agents

Reviews & Community


Write a review

    Add a:
  • Photos
  • Videos

No file chosen

Rather attach a photo from your computer?


Product Fit:

Runs smallTrue to sizeRuns large

Add Your Size


Height (ft, in):

Weight (lbs):

Size Purchased:

Only jpg, jpeg, png, gif or bmp files please.

Submit ReviewCancel
Avg. ride time: 4m per week
  • Average ride time is based on Strava activity over the last 3 months. Give your reviews credibility by connecting your account.


    The proof is in the pudding. There is little argument that electrolyte drinks may help to prevent dehydration. The idea of "pre-load" is interesting but flawed. The only way this could help is if the user starts in a slightly dehydrated state (which is probably true of most competitors).

    Pre-load in medical parlance refers to the amount of blood that comes into the left ventricle and not used in the manner described in the advertisement.

    Increasing plasma volume is useful up to a point after which you will just make more pee. Don't get me wrong, it's good and important to pee a lot especially in the heat but it's not like you store the extra plasma volume like a camel as the "hyperhydrated state" implies.

    Blood must have a certain level of acidity for the cells of the body to operate optimally. If the blood is too acidic or not acidic enough the cells of the body don't work well. The body has several mechanisms to buffer acidity to maintain a proper balance. The amount of base (or bicarbonate in this case) is likely relatively modest and would likely be buffered by the body's homeostatic system. As the added base is likely to be buffered almost immediately it is unlikely to be of benefit when it is touted to be helpful. Interestingly, this product contains both sodium citrate (which metabolizes to an acid) and sodium bicarbonate (which metabolizes to a base). Net result? Probably zero.

    Bottom line: Buy it if it is cheap and you like the taste. Electrolyte drinks help you to stay hydrated and maintain proper balance of salts in your body. The rest of the claims are a lot of bunk and pseudo-science. Sodium citrate provides a nice tang to the drink but it (as well as the sodium bicarbonate) is unlikely to be in sufficient quantities to have the claimed effects (which is probably a good thing since it would wreck your body's own homeostatic systems if it actually made your blood more or less acidic than it should be).

    Avg. ride time: 51m per week
    • Average ride time is based on Strava activity over the last 3 months. Give your reviews credibility by connecting your account.

    Tough to drink, makes a huge difference

    • Familiarity: I've put it through the wringer

    While the taste might be a bit tough to take (salty, but not gag material), it makes a huge difference for me on hot days on the road. Start out hydrated, and easier to stay hydrated. Enough of a difference that I'll continue to use it.