In environments where the loss of fluids and salts is extremely high, such as hot/moist and/or high climate or windy and hot environment, said loss generally causes loss of performance for an athlete or even disorders in the consciousness and increases the risk of e.g. arrhythmia. In such conditions the problem also is the decrease in the volume of blood fluid, i.e. the decrease in plasma volume. This is caused by the loss of blood to the surrounding tissues because salt is sweated out from the blood (exercise-associated hyponatremia). This risk is high especially in high-performance and long-lasting performances during which the intake and the absorption of fluid from the digestive track is disturbed. In such situation the fluid to be consumed should irritate the stomach and digestive track as little as possible and it should be able to prevent the drying of the body.

Generally sports drinks are used to balance this condition. One generally known example of such product is Gatorade®, which is described in GB 1252781 , wherein the drink contains 21 meq/l of sodium, 2 meq/l of potassium and 6% of sucrose.

US4042684 describes a beverage for supplementing the dietetic requirements of sugar and essential salts in a mammalian body depletable through vigorous physical activity, whereby the level of available utilizable energy stores within the body are enhanced, comprising an aqueous solution of sugar, sodium chloride, potassium chloride, and free citric acid in precise compositional ranges. However, normal sports drinks contain generally lots of fluid (water), quite a lot of sugar and small amounts of salts. The problem with such drinks is that the drink does not remain in the blood but the fluid "leaks" out from the plasma resulting in an increase in hemoglobin concentration. Also the concentration of urine will be increased. Therefore such sports drinks provide only a temporary help in maintaining the fluid balance of the body.

There is still need for more efficient recovery drinks which could maintain the fluid balance and therefore the performance of the athlete for a longer time.

Brief description of the invention

In the present invention it was surprisingly discovered that when certain amounts of salts and proteins and only a minor amount of sugars were used in a sports drink, it could maintain the fluid balance for a prolonged time. This is likely caused by the amino acids contained in the proteins preventing the leakage of the fluid from the blood. Most likely the synergetic effect of proteins and salts together cause the increase and/or maintenance of the osmotic pressure thereby keeping the fluid in the plasma.

The present invention provides a drink composition for maintaining and/or restoring the fluid balance during a sports event or an exercise, wherein the drink composition contains proteins in the range of 0.5-0.15% (w/v), carbohydrates in the range of 1.3-2.0% (w/v) and salts in the range of 0.08-0.12 (w/v).

The present invention also provides use of said drink composition for maintaining and/or restoring the fluid balance during a sports event or an exercise. One advantage of the present invention is that the fluid, carbohydrate and electrolyte balance of the body can be recovered and/or maintained for a long time during a sports event or an exercise.

Another advantage of the present invention is that the high concentration of urine can be avoided during a sports event or an exercise.

Still another advantage of the present invention is that it maintains the endurance.

Brief description of the drawings

Figure 1 shows the acute change in body weight during a 30 km high performance test run in a hot and high environment. Group 1 (n=5) consumed 100 cl of a traditional sports drink and Group 2 (n=5) consumed 100 cl of the drink composition of the invention.

Figure 2 shows the acute change in the urine specific gravity during a 30 km high performance test run in a hot and high environment. Group 1 (n=5) consumed 100 cl of a traditional sports drink and Group 2 (n=5) consumed 100 cl of the drink composition of the invention.

Figure 3 shows the daily change in body weight (BW) and the urine specific gravity (USG) for one runner during one week. The exercise was carried out in the same environment as the 30 km test run.

Detailed description of the invention The present invention provides a drink composition for maintaining and/or restoring the fluid balance during a sports event or an exercise. Especially suitable sports or exercises are those which cause high loss of fluids and drying of the body. For example exercises carried out in a high climate or windy and hot environment or high-power or long-lasting exercises will cause such loss of fluids and therefore recovery or maintenance of the fluid balance is required. The drink may be consumed before, during or after the exercise.

The drink composition contains proteins, which help to keep the consumed fluid in the circulation. The protein concentration is in the range of 0.05-0.15% (w/v), preferably 0.07-0.13% (w/v). In one embodiment the protein concentration is about 0.1 % (w/v). Any suitable protein may be used, but preferred are proteins having a good amino acid profile, such as whey proteins.

The drink composition also contains carbohydrates, which maintain the sugar balance of the blood and muscle glycogen. The carbohydrate concentration is in the range of 1.3-2.0% (w/v), preferably 1.45-1.55% (w/v). In one embodiment the carbohydrate concentration is about 1 .5% (w/v). In one embodiment the carbohydrates are sugars. Monosaccharides are preferred, such as glucose and fructose, because of their fast effect. Also disaccharides, such as saccharose, may be added. In some cases also longer carbohydrates, such as glucose polymer maltodextrine, may be added in small amounts as support, for example 5-10%. Also combinations thereof may be used, but especially glucose is preferred. In one embodiment the glucose is provided as syrup. In any case, the sugar concentration should not exceed 3% because too concentrated sugar solution causes osmotic pressure which slows down the stomach functions.

The drink composition further contains salts, which will replace the salts lost during the exercise and maintain and recover the natural salt concentration. The salt concentration is in the range of 0.08-0.12% (w/v), preferably 0.09-0.11 % (w/v). In one embodiment the salt concentration is about 0.1 % (w/v). Suitable salts include sodium, potassium, such as sod ium chloride or potassium chloride, and combinations thereof. Also other salts may be included, such as magnesium. Generally sodium is the most important salt especially to avoid hyponatremia.

In one embodiment the drink composition of the present invention contains substantially about 0.1 % (w/v) of proteins, about 1.5% (w/v) of carbohydrates and about 0.1 % (w/v) of salts. It is essential for the present invention that the concentrations do not vary too much from these values. The preferred ranges are optimal.

In another embodiment the drink composition of the present invention contains substantially about 0.1 % (w/v) of whey proteins, about 1.5% (w/v) of sugars, preferably monosaccharides, such as glucose, and about 0.1 % (w/v) of salts, such as sodium chloride and optionally potassium chloride.

It is essential that the osmolality of the drink composition is not too high causing the fluids to flow from the body into intestines. The drink composition should have osmolal ity of less than 300 mOsm/l , preferably less than 280 mOsm/l . Theoretically about 250 mOsm/l would be optimal.

The drink composition of the present invention may also contain such as preservation agents, e.g. potassium sorbate or sodium benzoate. Also pH- adjusting agents may be included, such as bicarbonates and citrates. The citrates are preferred because in the body they are more potent buffering agents that bicarbonates. Suitable citrates include e.g. tripotassium citrate and magnesium citrate. In one embodiment the pH of the drink composition is about pH 4.0. In another embodiment the Brix of the drink composition is about 3.1. Also other suitable further ingredients may be included, such as antioxidants or flavoring agents.

In one embodiment the drink composition is provided in a form of a concentrate. One embodiment of the present invention provides the use of said drink composition for maintaining and/or restoring the fluid balance during a sports event or an exercise.

Examples

The aim of the next study was to find out if the drink composition of the present invention can prevent drying of the body of international level long distance runners during a high power and long lasting run performance in a high and hot environment. Ten (10) runners (see Table 1 ), who had exercised before the study in Eldoret, Kenya at 2,000-2,200 m for at least one month, took part in the study.

Table 1. Background of the runners (n=10)

The runners performed a 30 km test run on a route starting from 2,100 m and ending at 2,200 m from the sea level. The run was started after a ten-minute warming-up at 11 :00 when the temperature was 25°C. During the whole test run the sun was shining from a cloudless sky and the temperature rose about 2°C.

Immediately before and after the test run the runners were weighed and they gave a urine sample for determining the urine specific gravity. The runners were divided randomly into two groups. The first group (Group 1 ) consumed during the warming-up and the run 100 cl of a sports drink containing short-chain carbohydrates (4%). The second group (Group 2) consumed 100 cl of the drink composition of the invention containing 0.1 % (w/v) of whey protein, 1.5% (w/v) of glucose and 0.1 % (w/v) of sodium chloride.

The body weight of the runners was measured with a scale having an accuracy of ±100g. The urine specific gravity was measured with a portable digital refraction meter wherein the most diluted (=water) urine specific gravity was 1.000.

The results were studied as means and standard deviation. The difference in the body weight and the urine specific gravity was tested with a two-way repeated measures variance analysis. P<0.05 was used as the level of statistical significance.

Results

The runners of the both groups run the 30 km test run in almost the same time. The time of the first group was 1 :46:02±0:00: 16 and the second group 1 :46:08±0:00:16. During the run the body weight decreased a substantially equal amount for both groups: 3.5±0.6% for the first group and 3.7±0.7% for the second group (Figure 1 ).

The urine specific gravity changed differently (P<0.05) between the two groups. In the first group the specific gravity increased on four runners (average 0.1 ±0.3%) but in the second group it decreased in all the runners (average 0.4±0.1 %) (Figure 2).

Conclusions

The study demonstrated that the drink composition of the invention turned the urine into more dilute when compared to a traditional sports drink generally used in such long-distance performances in a demanding environment. When consuming the drink composition of the invention, none of the runners had their urine concentrated during the performance in spite of a high loss of fluids (over 3%). Low urine specific gravity is generally associated with good hydration condition.

According to further follow-up monitoring of one runner, it seems that the urine specific gravity decreases systematically every day in spite of the loss of fluid and acute body weight (Figure 3). It wil l be appreciated that the methods of the present invention can be incorporated in the form of a variety of embodiments, only a few of which are disclosed herein. It will be apparent for a person skilled in the art that other embodiments exist and do not depart from the scope of the invention. Thus, the described embodiments are illustrative and should not be construed as restrictive.