High 5 Zero review: Runners’ favourite High 5’s electrolyte tablets are free of sugar but full of flavour…

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High 5 Zero


£7.99 per tube (20 tablets) or £62.99 for 8 tubes, highfive.co.uk (not available in the US)


  • Great taste with lots of flavours to choose from
  • Good value for money
  • Convenient as mixes with 750ml water (sports bottle size)


  • Heavy, salty sweaters may want more sodium per serving
  • Vitamin C is not needed for hydration
  • Some flavours contain small amounts of caffeine

Taste: 4.5/5
Solubility: 5/5
Effectiveness: 5/5

High 5 is a popular brand with runners and one that’s been around for a long time. So Zero hydration tablets are a product from a trusted player in the sports nutrition supplement market. They contain a range of electrolytes (five – hence the name of the company and its flagship product) and enough sodium (250mg per serving) to prevent hyponatremia and support good hydration during exercise.

High 5 Zero benefits

High 5 Zero tablets are suitable for anyone engaging in prolonged exercise. However, heavy, salty sweaters may want something with a slightly higher sodium content. The citrus flavour we tested has a nice balance of sweet and tangy flavour. The tablets are sugar-free and sweetened with sucralose, so they’re low in calories. They’re made with natural colourings too.

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High 5 recommends a dose of 1 tablet in 750 ml of water, which is enough to fill a standard-sized water bottle. So it’s convenient when you’re training for extended periods or competing in an event. If you wanted a higher amount of sodium, you could add two tablets, though that would probably make the drink too sweet. These Zero tablets dissolve easily in water without any additional shaking.

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The tablets contain vitamin C, which is a useful inclusion for several reasons. It’s known to improve immunity and plays an important role as an antioxidant, but it’s not necessary for hydration. However, it’s important to note endurance athletes should avoid any supplements containing antioxidants during the adaptation phase of their training.

Some flavours contain green tea, which has a little caffeine. It’s a minimal amount, but it’s still worth bearing in mind. Particularly if you’re sensitive to caffeine or tend to train late at night.

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High 5 uses the same compact and convenient tube packaging as the likes of SIS, so will take up minimal room on your kit bag. At 40p per serving it’s good value for money and there are nine flavours to choose from.