Ethan BrooksBy Ethan Brooks

Updated November 2026

A sis go energy electrolyte gels 20 pack gives you a full training block’s worth of fuel in one box. This guide shows you how to count your gel needs, time your intake on long runs and race day, train your gut so nothing surprises you on the course, and avoid the mistakes that cause stomach trouble. By the end, you will have a simple plan for using the gels across your marathon build.

What a 20 Pack Covers and Who It Suits

Each SiS GO Electrolyte gel is a single-serve pouch built around a carbohydrate and electrolyte mix designed to be taken without water. The brand’s product information lists a carbohydrate figure per gel, and the exact amount varies by flavor and version, so check the label on your box before planning. A 20 pack is a practical size for a single marathon cycle or for a runner who uses gels on every long run plus race day. It is less useful for runners who only need one or two gels per season, since opened pouches should be used promptly. Do SiS Energy Gels with Electrolytes Work? A Runner's Guide goes further into this.

Shopping for one? See our guide: SiS GO Energy Gels Review: Features and Performance.

Before buying in bulk, confirm that the gel is compatible with your stomach. Many runners find the electrolyte-enhanced formula easier to take than plain gel because the sodium helps with fluid balance during sweaty efforts. Others find it tastes too sweet after an hour. Test a few gels on a medium-length run before committing to a full 20-count.

Step 1: Calculate How Many Gels You Need

Start with carbohydrate targets rather than a fixed number of gels. Sports nutrition guidance commonly suggests roughly 30 to 60 grams of carbohydrate per hour for events lasting longer than about 90 minutes, with some athletes tolerating more when they have trained for it. To turn that into gels:

  1. Find the carbohydrate grams per gel on the packaging.
  2. Divide your target hourly carbohydrate by that number to get gels per hour.
  3. Multiply by the number of hours you plan to run with fuel.
  4. Add a spare gel or two for dropped pouches or a missed fueling window.

For example, if a gel supplies about 22 grams of carbohydrate and you aim for 60 grams per hour, you need roughly 2.7 gels per hour. Round to a practical schedule, such as one gel every 25 to 30 minutes, and remember that exact figures come from the product label, not from this guide.

Sample Gel Count Across a Training Block

Run Type Typical Duration Suggested Gels
Easy medium run 60 to 75 min 0 to 1 (test only)
Mid-length long run 90 to 120 min 2 to 3
Peak long run 150 to 180 min 4 to 6
Marathon race day 3 to 5 hours 4 to 8, including early and mid-course use

Plan to use roughly half your 20 pack in training and save the rest for race week and race day, or buy a second box if your long run volume is high.

Step 2: Time Your Gels on the Run

Gel timing matters more than gel count. Starting too late forces you to play catch-up, and taking a gel too close to a hard surge can upset your stomach.

  • Take your first gel 20 to 30 minutes into the run, not at the start, unless your pre-run meal was light.
  • Space gels every 25 to 35 minutes after that.
  • Wash the gel down with water at aid stations or with a few sips from your bottle. Water helps with absorption, but do not gulp large volumes.
  • Avoid taking a gel in the final 10 minutes before a hill or sprint, when your effort is already high.

If you want a more detailed breakdown of timing for different race distances, see When to Take Energy Gels: A Marathoner's Timing Guide. For half marathon specifics, When to Take Energy Gels During Half Marathon: A Step-by-Step Timing Guide covers a shorter schedule.

Step 3: Train Your Gut Before Race Day

Gut training is the step most runners skip, and it is the one that prevents most fueling disasters. The digestive system adapts to carbohydrate intake over several weeks, so the gel you take at mile 18 should already be familiar.

  1. Start with one gel on your longest runs once you pass 60 minutes.
  2. Increase by about one gel per long run over three to four weeks until you reach your race-day rate.
  3. Take each gel at the same time and with the same water or drink you plan to use on race day.
  4. Note any cramping, bloating or nausea in a training log so you can adjust the schedule.

Many runners find that a combination of gels and a sports drink works better than gels alone. Consider the total carbohydrate from both sources so you do not overload your stomach.

Step 4: Plan Your Race-Day Setup

Race day should follow the exact pattern you practiced. Use this checklist the week before your marathon:

  • Confirm your gel count matches your planned schedule, plus two spares.
  • Decide where you will carry gels: a running belt, waistband pocket or a hydration vest.
  • Check the course for aid station locations and whether they offer water, sports drink or both.
  • Pack gels in a way that keeps them accessible, such as with a tab or a pocket you can open one-handed.
  • Do not try a new flavor or brand on race morning.

Common Mistakes to Avoid

  • Relying on the box count instead of the carbohydrate label. Plan from grams, not pouches.
  • Skipping gut training. Taking gels for the first time in a race is a common cause of stomach distress.
  • Taking gels without water. Some runners find the thick texture hard to swallow dry. Sip water with each gel.
  • Storing the box in a hot car. Heat can change the texture and make gels harder to tear open. Store them somewhere cool and dry.
  • Stacking gel intake on top of a large breakfast. Account for everything you eat in the two to three hours before the start.

For ideas on how gel use fits into a broader fueling strategy, the article Science in Sport Isotonic Energy Gels: How to Use Them for Marathon Fueling explores related approaches, and SiS Energy Gels 30 Pack: How to Choose, Use and Fuel Your Long Runs discusses bulk purchasing for longer training cycles.

Several accessories make a 20 pack easier to use on the road. A running belt with dedicated gel loops keeps pouches within reach. A small hydration vest is useful for longer training runs where you need to carry water and multiple gels. Lightweight tear-proof storage bags help keep opened gels clean.

  • Running belt with gel loops: Holds several pouches without bouncing, so you can grab one without slowing down. View on Amazon
  • Hydration vest: Useful for long training runs where you carry water, gels and a phone. View on Amazon
  • Insulated bottle belt: Lets you carry a sports drink alongside your gels so you can wash each one down. View on Amazon

FAQ

How many SiS GO gels should I take per hour?

Most runners aim for about 30 to 60 grams of carbohydrate per hour, which usually means one gel every 25 to 35 minutes depending on the label. Start at the lower end and build up through training.

Do I need to take the gels with water?

Water helps most runners swallow the gel and supports absorption. Sip a small amount with each gel rather than drinking large volumes.

Can I use a sis go energy electrolyte gels 20 pack for a half marathon?

Yes, though many half marathoners need only one or two gels, or none if they fuel well beforehand. Use gels only if your race exceeds about 75 to 90 minutes or your pre-race fueling was light.

How long do opened gels last?

Once opened, finish the pouch in one sitting. Do not save partial pouches for later, as contamination and texture changes become more likely.

Should I take gels during training or only on race day?

Take them during long training runs. Gut training is one of the most effective ways to avoid problems on race day.

What if a gel upsets my stomach?

Reduce the number of gels or space them farther apart, and drink more water. If symptoms persist during training, consider trying a different gel or consulting a sports dietitian or physician, especially if you have a digestive condition.

Are the gels suitable for everyone?

Individual tolerance varies. Runners with diabetes, digestive conditions or other health concerns should consult a doctor or registered dietitian before changing their fueling plan.

Conclusion

A sis go energy electrolyte gels 20 pack works best when you plan from carbohydrate targets, time your intake every 25 to 35 minutes, and train your gut across several weeks of long runs. Use the table and checklists above to match gel counts to your training and race plan. Test everything in training, carry a spare or two on race day, and adjust based on how your stomach responds.

Ready to choose one?

Ethan Brooks

About Ethan Brooks

Ethan Brooks is part of our editorial team and reviews and edits our marathon & half-marathon guides, checking product details against manufacturer specifications and owner feedback.