You may have often read that you should take supplements such as creatine with fruit juice. Does it matter what type of juice that you use and is it better to perhaps stick with water?
The short answer is yes. All juices have chemical properties that vary from juice to juice. When it comes to selecting one to mix with your supplements, the criteria most people likely
consider are taste, consistency and availability of the juice. When you make your selection, you should also consider the sugar composition of the juice, timing, and the effects that
certain juices produce in the body.
Glycemic index is a measure of a particular food's ability to elicit the release of insulin from the pancreas into the blood. In other words, for our purposes, this means how fast the
juice will take to be broken down and absorbed in the bloodstream.
Probably the most important property of juice to consider is its relative sugar composition. The ratio and type of sugars in juice determine both its glycemic-index value and dehydrating
potential. For example, a juice high in glucose (i.e., grape juice) will tend to have a higher place in the glycemic index, while a juice high in fructose (apple juice) will tend to have
a lower glycemic-index value.
Juices with high glycemic-index values are the best choice to use with creatine or amino acid supplements. A high-glycemic juice will cause a rapid increase in plasma insulin, which
will in turn increase the abundance and activity of skeletal-muscle sodium pumps. Since these pumps are responsible for providing the energy for crea-tine and amino acid transport into
muscle cells, the resultant increase in skeletal-muscle sodium pump activity enhances the uptake of creatine and amino acids. Grape juice and orange juice, both high-glycemic juices,
are good choices for mixing with creatine monohydrate and amino acid powders.
In general, it's better to supplement after your workout, but many people do supplement, as well as simply drink the juice itself, before training. If you drink a high-glycemic juice
before you work out, you'll tend to get a sugar spike - and subsequent plummet - which will negatively impact your workout. After a workout is the best time for high-glycemic juice
supplementation. At that time, your body will be better able to shuttle supplements such as glutamine and creatine into your muscles; again, orange and grape juice are ideal for this.
If you do supplement before your workout, you should choose low-glycemic juices because they provide a better boost for energy and endurance. A low-glycemic juice will elicit a slower
release of insulin and will allow for a sustained delivery of sugar from the blood to the muscle cells. Therefore, the muscles will have a constant supply of sugar available for energy
production during your workout. Juices with low glycemic-index values include apple juice and grapefruit juice.
OTHER BIOLOGICAL EFFECTS
To further complicate things, juices contain a complex array of phytochemicals that exert a host of biological effects. For example, the phytochemicals in grapefruit juice can alter
the bioavailability of certain drugs. Therefore, you should consult your doctor about the use of grapefruit juice when taking medication such as some antibiotics and some high-blood-pressure
Since apple juice is fairly high in sorbitol, another type of sugar, you should make sure to stay well-hydrated while using it. Sorbitol is not metabolized well and has a tendency to
"pull" fluids from your system into your urine. Therefore, juices high in sorbitol (apple and cranberry juice) tend to have a high dehydrating effect. Dehydration can lead to a loss of
potassium, muscle cramping, and a generally lower-quality workout; you should therefore avoid consistent consumption of juices with a high sorbitol content. You may want to consider
using grapefruit juice instead, which also has a relatively low glycemic-index value, as long as you're not taking certain medications (check with your doctor).
Another consideration when selecting a juice is the actual juice content of the product. Just because a product claims to contain 100% juice does not mean that it contains only 100%
juice. The typical phraseology is "100% fruit juice drink." This is a crafty manipulation of semantics to make you believe you're getting the real thing, when, in fact, this beverage may
contain as little as one part 100% juice to nine parts water and corn sweetener. This means that you would be consuming a product containing only 10% juice, which is not very different
from the chemical components of a soft drink. And the problem with these "juice drinks" and "juice cocktails" is you don't know what type of sugar you're getting, so you don't know what
effect the drinks would have upon your workouts and supplementation.
Many people warn against juices made from concentrate, but all this really means is that the water has been removed for easier transport, then later replaced. In essence, the sugar
composition of orange juice made from concentrate should be nearly the same as fresh orange juice, and the same holds true for other juices.
How can you be certain that the juice you consume is 100% juice? The best way is to extract the juice yourself. If you don't want to go to that much effort, read the nutrition label.
Avoid drinks with added sugars.
The bottom line is that juices contain bioactive compounds that have physiological effects; properties of a particular juice can and should be used to your advantage.
Next time you reach for a bottle of juice to mix with your supplements, don't let taste be your only guide.