Research Study


SOS releases research study challenging the effectiveness of sugar in sports drinks.


For many years Oral Rehydration Therapy (ORT) has been used to treat mild to moderate dehydration due to cholera and other gastrointestinal pathologies all over the world. It has saved more than 5 million lives, and it has proven its effectiveness through a myriad research studies. SOS Rehydrate applies the same principles used in the clinically proven ORT, to hydrate athletes and those with active lifestyles.

But how does it work? Water and electrolytes get absorbed all over the intestinal lumen through specialized energy-dependent pumps and co-transports. Within the small intestine there is a co-transport system that links one molecule of sodium to one of glucose; transferring sodium through the intestinal membrane into the blood stream. As a result of this sodium movement (osmotic gradient) water gets transported into the plasma. In essence by mixing the correct amount and ratio (1:1) of sodium and glucose the water absorption process gets enhanced by up to 3 times. Additionally this osmotic balance can aid in greater fluid retention, as renal reabsorption of water is favored in these conditions. However, as much peer reviewed clinical research has been conducted on the efficacy of a 1:1 sodium and glucose solutions osmolality, and resultant rapid fluid uptake, performance specific testing of this is a relatively new endeavor. To preliminary investigate the effectiveness of SOS Rehydrate verses the current Sports drink market leader, SOS Rehydrate commissioned the following study.


Effects of ingestion of SOS Rehydrate vs. Sports drink Market Leader on subsequent aerobic exercise:

This study, conducted by the Sports Performance Research Institute of AUT University comprised 8 mid level distance runners (6 males, 2 females) who performed two single blind trials in which they consumed 500 ml of either the current sports drink market leader (ML) or SOS, followed by a 75 minute treadmill run in a climate controlled room (~23 deg C, 60%rH), at a speed equivalent to 70% of their predetermined VO2 max. Prior to, Post, and every 20 minutes during these trials, measures of the runners’ blood glucose and blood lactate levels, as well as their heart rate, blood pressure, Rate of Perceived Exertion and feelings of thirst and thermal fatigue were collected and recorded. Additionally, to determine the runners’ hydration statuses prior to, during (if runners had to urinate during trial), and immediately post each 75-minute trial, measures of urine specific gravity and volume of urine produced were taken. Insensible and evaporative fluid loss, from sweating and breathing, were accounted for by pre and post body weights, and as the subjects were restricted from eating or drinking during the protocols, all weight loss was assumed to be due to fluid loss.



Following the completion of data collection, all subject data was averaged, and trial group means and standard deviations for each time point were generated. Upon statistical review, it was determined that for all recorded measures there were no statistically significant differences between either trial conditions means. 

Below Figures 1-3 depict the mean trial values of Heart Rate, Blood Lactate, and Blood Glucose respectively.

Figure 1

Mean heart rate data showed near perfect replication during each trial, with no differences seen at any time point.

Figure 2

Slight variations of the Mean Blood lactate levels, with respect to each trial condition, were seen at 40 and 60 minutes. However, these variations were not great enough to result in a statistically significant difference between trials. It should also be noted that 50% of the subjects who urinated mid trial did so between the 40th and 60th minutes. This mid-trial urination required a brief (1-2 minute) break from exercise, and may potentially have resulted in decreased blood lactate levels on subsequent measures.


Figure 3

Mean Blood Glucose profile during 75 min running trial.

In Figure 3, both ML and SOS Rehydrate demonstrate an initial dip in blood glucose levels after the initiation of exercise, however both levels rebounded by the 40-minute time point and held constant till the end of the trial.

While no statistically significant difference in measures were seen between trials, some interesting trends in the data did appear. The most interesting of which is that 50% (4 subjects) of the ML group had to urinate during their trial, as compared to 12.5 % (1 subject) in the SOS Rehydrate trial. This trend of 50% of the subjects urinating mid ML trial, as well as the volume of urine produced by these subjects, raises questions about the subjects blood plasma osmotic gradient and subsequent water re-absorption rates and long term hydration status. Subsequent studies should be performed to better ascertain the effects of consuming a high carbohydrate content drink, such as the market leader, on fluid retention rates and long term hydration status. The urine volumes produced can be seen below in Figure 4.

Figure 4

Figure 4: Mid-Trial Urine Production Volumes

Significance of study results:

As no significant changes were seen in any performance or physiologic measures taken during this study for either group, the only true difference between trials was the fluid type ingested (SOS Rehydrate or ML). This presents an interesting question, as the ML contains a greater than 7 fold more carbohydrates in the form of sugar (36 grams compared to 5 grams), than SOS Rehydrate, yet all physiologic, perceptual and performance measures were nearly identical across the two trials. In addition the high sugar content of the ML, which resulted in no increase in performance, could potentially lead to a unfavorable osmotic gradient change that long term would result in a decreased water reabsorption rate, an increased urine production rate and subsequent dehydration. SOS Rehydrate, with its WHO recommended and osmotically balanced 1:1 ratio of sodium and glucose, is able to provide substantial rehydration and fluid retention, without the unnecessary excess sugar that the majority of sports drinks, including the tested market leader, contain. This hydration capability, coupled with a low sugar content, is what makes SOS Rehydrate the go to drink of choice for many elite athletes.


Future Studies:

This study was a positive step in demonstrating the effectiveness of SOS Rehydrate, and its 7 fold reduction in sugar content, in hydration and running performance when compared to the market leader. SOS Rehydrate is committed to furthering sports performance and hydration research, and as such will be initiating future studies to further investigate the effect of SOS Rehydrate on hydration status and performance, as well as post ingestion fluid retention rates.