Like this site? Help us to make it better.

Science in Sport GO Hydro - Cola and Caffeine (20 Tablets)



Handy drink to help you stay hydrated when exercising, with the additional benefit of caffeine.

At every product is thoroughly tested for as long as it takes to get a proper insight into how well it works. Our reviewers are experienced cyclists that we trust to be objective. While we strive to ensure that opinions expressed are backed up by facts, reviews are by their nature an informed opinion, not a definitive verdict. We don't intentionally try to break anything (except locks) but we do try to look for weak points in any design. The overall score is not just an average of the other scores: it reflects both a product's function and value – with value determined by how a product compares with items of similar spec, quality, and price.

What the scores mean

Good scores are more common than bad, because fortunately good products are more common than bad.

  • Exceptional
  • Excellent
  • Very Good
  • Good
  • Quite good
  • Average
  • Not so good
  • Poor
  • Bad
  • Appalling

Go Hydro + Caffeine is a product from Science in Sport (SiS) designed to help you stay hydrated when exercising, with the additional ingredient of caffeine which provides a small but noticeable increase in mental and physical performance.

Previously on we reviewed the 'normal' Hydro tablets from SiS. The caffeine version looks pretty much the same: a tube of tablets consisting of various minerals or electrolytes. You bung a tablet in a bottle of water, wait while it dissolves, then drink it.

SiS says that the electrolytes (sodium, calcium, magnesium, potassium and zinc) replace those lost from your body via sweat and encourage you to drink the right amount, which in turn helps performance. And most sports science studies agree that dehydration can have a negative impact on performance (basically, you get tired sooner), and that drinking the correct amount of water helps avoid this.

But after this, there's a divergence regarding electrolytes. Some studies show that replacing the electrolytes helps further improve performance and avoid cramp. Other studies show that you don't need extra electrolytes, and that drinking water is enough. A middle way claims that the electrolytes in the fluid, even if not actually needed, still encourage you to drink the correct amount and stay hydrated. A fourth school of thought claims that it's the taste of hydration products, rather than the electrolytes, that encourage you to drink - because it's nicer than boring old water.

So that's the arguments for and against electrolytes. But the Go Hydro + Caffeine tablets have another added ingredient. As the name suggests: caffeine. According to SiS this provides an extra mental and physical boost, just like your morning Americano.

I first tested Hydro + Caffeine by drinking a 500ml bottle of water mixed with one tab (as recommended) at home. It comes in only one flavour: Cola. And although the SiS website describes this product as 'effervescent' it was nowhere near fizzy. Certainly nothing like big brand name colas. The taste was pretty bland too; like weak, flat Coke.

The next test was before a ride. I consumed about 300ml before a 100-mile sportive. On the up side, it definitely gave me a little kick, just as if I'd had a coffee, and I felt pretty good during the first hour, when normally I take a while to warm up. On the down side, I needed a pee after cycling about 20 miles, when normally I wouldn't.

Whether it was the fact I'd consumed more liquid than I normally would before a ride, or the diuretic effect of the caffeine, which may partly counter the hydration benefits, I don't know. And it might just be a personal thing for me (I am old, and male, so always follow the advice of Jack Nicholson's character in The Bucket List to 'never pass up a bathroom'), but at the end of the day it's the same for every rider: the only way of seeing if these Hydro + Caffeine tablets have an effect – positive or negative – for you is to try them.

If drinking before you start provides a boost in the early part of a ride, without any side effects, then stick with 'em. If they don't work for you, then leave them alone. It may also be a drink better suited to short fast rides than the more steady pace of an endurance sportive.

On the SiS website is another recommendation: to use Go Hydro + Caffeine during a ride – presumably sipping on it for an hour or two as you would on a normal drink. I tried this, but found no noticeable benefit. Again this may be a personal thing. Caffeine for me seems to be more effective if it comes as a hit (eg, in a gel) rather than a drip feed. But for other riders it may be the other way around. Once again, trial and errors for your own personal circumstances is the best way forward. And at £3.99 for a trial pot of 10 tabs, it's not going to break the bank, so on that basis, I'd recommend SiS hydro with caffeine as well worth trying.

Once you've decided to stick with Hydro + Caffeine, a 20-tablet tube costs £6.99 on the SiS website (or a penny under 30 quid for eight 10-tab tubes). As well as on-line, you can buy SiS products at your local bike shop or sports store, and in a few supermarkets.


Handy drink to help you stay hydrated when exercising, with the additional benefit of caffeine to enhance mental and physical performance. May not suit all riders though. test report

Make and model: Science in Sport GO Hydro - Cola and Caffeine (20 Tablets)

Size tested: N/a

Tell us what the product is for, and who it's aimed at. What do the manufacturers say about it? How does that compare to your own feelings about it?

This is a hydration product, designed to help you stay properly hydrated (ie drink the right amount) during exercise. It has virtually no carbohydrate so it is not an energy product.

The SiS website says Go Hydro + Caffeine is a 'low-calorie high electrolyte effervescent tablet with added caffeine used to hydrate and provide a mental and physical boost during training or racing' and highlights the following features:

* Simply drop in water to provide a high electrolyte drink

* High in sodium to help promote hydration

* 75 mg caffeine per tablet

* Store in a cool dry place

* Suitable for Vegans

Tell us some more about the technical aspects of the product?

The SiS website goes on to give a lot more information, including:

'SiS GO Hydro + Caffeine builds upon the scientifically based formulation of SiS GO Hydro by ensuring you are effectively hydrated for performance whilst also providing 75 mg of caffeine per tablet. As an effervescent tablet that readily dissolves in plain water, it represents a highly practical approach (simply drop one tablet in your 500 ml water bottle) to ensure that all of your electrolyte, fluid and caffeine requirements are met in its most simple format. The addition of caffeine has been repeatedly shown by sport scientists to improve performance by providing both a physical and mental boost just when we need it. SiS GO Hydro is a practical strategy to ensure hydration without the calories.'

On the caffeine ingredient specifically, the SiS website says: 'Caffeine can increase fat utilisation therefore effectively sparing the use of our limited carbohydrate stores for later use during exercise. Caffeine can also have direct effects on the brain by improving reaction times and lowering our perception of effort for a given workload, thus making the exercise now seem easier.'

Rate the product for performance:

Performance was very good, in that the caffeine provided a mental and phyisical benefit.

Rate the product for value:

A tube of 10 tabs costs £3.99 so about 40p each. A tube of 20 tabs costs £6.99 so about 35p. This is on a par with the price of similar products such as High5 Zero Xtreme, so on that basis is fair value.

Tell us how the product performed overall when used for its designed purpose

This product performed well in terms of helping with hydration and enhancing physical and mental performance, but it may have counter-effects on some riders, so should definitely be tested at home before being used in a race or sportive.

Tell us what you particularly disliked about the product

Taste was surprisngly bland, and not as 'effervescent' as expected.

Did you enjoy using the product? Yes, once I'd got the quantities right for my personal situation.

Would you consider buying the product? Maybe, but only to use before rides in small quantities, not during rides.

Would you recommend the product to a friend? Yes, but with the advice they tried it first to see if it suited their own situation.

Anything further to say about the product in conclusion?

Overall, Go Hydro + Caffeine works well in terms of helping with hydration and enhancing physical and mental performance. on that basis it would score 9. However, the taste isn't brilliant, while the price (although fair) is not a bargain, and it may have counter-effects on some riders, reducing the overall score to 7.

Overall rating: 7/10

About the tester

Age: 51  Height: 5ft 10 / 178cm  Weight: 11 stone / 70kg

I usually ride: an old Marin Alp, or an old steel classic  My best bike is: an old Giant Cadex (can you see a theme here?)

I've been riding for: Over 20 years  I ride: A few times a week  I would class myself as: Experienced

I regularly do the following types of riding: touring, club rides, sportives, general fitness riding,


Add new comment


GerardR | 10 years ago

At last, a tester in the same age group as me, who doesn't weigh 35kg and class himself (modestly) as "Expert". And another steel fan, as well! Can I be your new best friend?

Latest Comments