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ZoneX Buffer Mix

ZoneX Buffer Mix

Regular price £29.95 GBP
Regular price £55.00 GBP Sale price £29.95 GBP
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  • Buffers Lactate
  • Delays Fatigue
  • Gut Friendly
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ZoneX is a revolutionary bicarb drink mix that buffers lactic acid, helping you run harder for longer — without the gut issues, bad taste, or clunky prep of other bicarb products.

Product Details

What is ZoneX?
ZoneX is a performance-focused drink mix built to help endurance athletes train harder and race faster. It’s formulated with a precise blend of sodium bicarbonate, potassium bicarbonate, citric acid, and magnesium sulfate - ingredients clinically shown to buffer lactic acid, delay fatigue, and improve high-intensity performance. No stimulants. No sugars. No BS. Just pure metabolic support.

How does it work?
During high-intensity efforts, your body rapidly produces lactic acid as a byproduct of anaerobic metabolism. This acid accumulates in your muscles which lowers pH — leading to that familiar burning sensation, muscular fatigue, and a drop in power output; fatigue.

ZoneX helps combat this by buffering the production of lactic acid. The sodium bicarbonate in our blend neutralises excess lactate before it interferes with performance. The addition of potassium bicarbonate, citric acid, and magnesium sulfate improves absorption, reduces the risk of GI issues, and helps maintain electrolyte balance—making the product more tolerable than standalone bicarbonate.

Who is it for?
ZoneX is for runners, triathletes, and endurance athletes who want to train at a higher intensity, recover faster between efforts, and compete at their true physiological ceiling. Whether your aim is to train more effectively, set new PB's, or beat your rivals - if you're serious about improving, ZoneX is for you.

When should I take it?
ZoneX is designed for any session where intensity matters—interval workouts, threshold runs, time trials, or races from 800m to the marathon. It’s particularly effective in events that require prolonged effort above lactate threshold, where acid accumulation would otherwise limit output.

Mix one sachet with 300-500ml of water and drink it 60–90 minutes before your session or race. You’ll feel the biggest difference during hard efforts—intervals, tempo runs, races, or anything that pushes you near your limit.

Ingredients

ZoneX contains a blend of performance-enhancing compounds, backed by science and built for endurance:

Sodium Bicarbonate - A powerful buffering agent that helps neutralize lactic acid buildup in muscles — delaying fatigue and helping you push harder, for longer. Proven effective in dozens of endurance performance studies.

Potassium Bicarbonate - Works alongside sodium bicarb to support acid buffering, while improving taste and reducing stomach distress.

Magneisum Sulfate - Supports muscle function, hydration, and endurance by helping your body contract and relax muscles more efficiently. It also plays a key role in reducing bloating and gut discomfort.

Citric Acid - Naturally found in citrus fruits, citric acid aids digestion and pH regulation. It also helps improve solubility and flavour balance in the mix.

Natural Lime Flavouring & Sweeteners - Used in trace amounts to give ZoneX its zingy lime punch taste. No artificial dyes, no added calories — just a clean, punchy flavour that goes down easy.

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We're so confident in the quality of our blend that we offer a 99-day money back guarantee on all orders. If you don't love your fastr products for any reason whatsoever, we'll give you a full refund; no questions asked.

How to use

1. Shake one full sachet into 250–300ml of water. Shake or stir well until fully dissolved. This can be prepared the night before a race for ease of use.

2. Drink 60 to 90 minutes before your run. This gives your body time to absorb and activate the ZoneX blend.

3. Sip slowly - ZoneX is best consumed gradually over 10-15 minutes to reduce stomach discomfort.

4. Go to work - ZoneX is built for race day, hard sessions, or any time you're pushing the pace.

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  • "Crazy results"

    "Tried Zone X to see if I could get the bicarb benefits without the gloopy taste. WOW, yes; it works. Crazy results in training and can't wait to use in a 5k race this winter!"

    - Charlie, 37

  • "PB by 42 seconds"

    "Took ZoneX before my 10K and felt locked in the whole way. No fade, no burn — just flow. Smashed my PB by 42 seconds."

    - Harry, 20

  • "Finished strong"

    "Didn’t think a powder could actually make a difference. Turns out it does. Legs didn’t blow up like usual and I actually finished strong for once."

    - Sarah, 32

  • "Bicarb Works"

    "Heart rate stayed lower at the same pace, and I held threshold 10 minutes longer than normal. Bicarb works. ZoneX just makes it tolerable."

    - Morgan, 28

  • "Made a real difference"

    "I’m not an elite runner — just someone who wants to hit PB's. ZoneX made a real difference in my recent races. Felt strong, not shattered."

    - Pete, 36

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FAQ's:

What is ZoneX?

ZoneX is a pre-run drink mix formulated with a high-performance blend of two types of bicarb - sodium and potassium. It helps buffer the lactic acid buildup that causes your legs to burn and slow down — so you can hold pace longer and push harder, without the gut issues or bad taste of traditional bicarb products.

What events is ZoneX suitable for?

ZoneX is ideal for high-intensity efforts where fatigue builds quickly — like 5Ks, 10Ks, track sessions, hill reps, tempo runs, and threshold workouts. It’s especially effective in events lasting 3 to 30 minutes, where lactic acid accumulation is a major limiter.

For longer events (half marathon or above), it can still help during fast starts, surges, or negative splits — but it shines brightest when you're redlining.

How does sodium bicarbonate help with performance?

Bicarb helps to slow the accumulation of hydrogen ions (acid) in your muscles, delaying fatigue and allowing you to perform at higher intensities for longer.

Bicarb has been clinically proven for decades to improve endurance at threshold-level intensities.

Will it really improve my running times?

Recent peer-reviewed studies have shown bicarb supplementation can increase performance by up to 17% in real-world race efforts. That could mean seconds or even minutes off your PB, depending on distance.

Does ZoneX contain any banned substances?

No. ZoneX is free from ingredients on the WADA (World Anti-Doping Agency) prohibited list and is safe for drug-tested athletes.

Will it upset my stomach?

Unlike traditional bicarb gels or capsules, ZoneX uses a revolutionary blend of compounds that are designed to make it easy on the stomach. Most users experience no GI issues when taken as directed.

How do I use ZoneX?

Mix one sachet with 250–300ml of water and sip slowly over 10–15 minutes. Drink it around 60–90 minutes before your workout or race for optimal results.

Why do other bicarb products cause gut issues?

High doses of straight sodium bicarbonate can increase stomach acidity and cause gas, nausea, or diarrhoea. ZoneX is formulated to reduce that risk using balancing agents and a smoother delivery format.

What does 'buffer' mean?

Buffering means neutralising the acid that builds up in your muscles during hard efforts — helping you delay fatigue and push longer before hitting the wall.

Can I prepare ZoneX the day before a race/training?

Yes - you can mix a sachet of ZoneX into a drink bottle anytime up to 24 hours before consuming it. This makes it super simple and easy to prepare the night before, leaving one less thing to think about on race day!