7 Best SiS Energy Gels for Running: Our Picks Compared

By Lauren Holland

Updated November 2026

Choosing from the many SiS energy gels for running can feel like a guessing game, especially when every box promises the same thing: fast carbohydrates for long efforts. The real differences show up in the details. Carbohydrate load per gel, the mix of carbohydrate types, whether caffeine is included, how the gel is packaged, and how a flavor sits with your stomach all matter. This guide compares seven SiS-brand options using those criteria, drawing on manufacturer specifications, brand reputation for sports nutrition and patterns that owners commonly describe in their feedback. Nothing here is based on our own testing.

Our Top Picks

Quick Comparison

Science in Sport Fast-Absorbing Carbohydrate Energy (SiS BETA Fuel Neutral)

Science in Sport Fast-Absorbing Carbohydrate Energy, 1:0.8 Maltodextrin to Fructose Ratio, 40g Carbs, Exercise Over 90 Min SiS BETA Fuel Dual-Source Isotonic Energy Gel, Neutral, 6-Pack

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Best for: Overall balance for efforts over 90 minutes

This is a good fit for runners tackling marathons or long training runs who want a high carbohydrate dose per gel and a neutral taste that does not compete with sports drinks on course.

Key specs

• Dual-source carbohydrate blend in a 1:0.8 maltodextrin to fructose ratio
• 40g carbohydrate per gel, per the listing name
• Neutral flavor profile

Pros

• High carbohydrate load suits long efforts
• Dual-source formula is designed to support higher intake rates
• Neutral flavor works with plain water or sports drink

Cons

• Larger dose may be more than shorter runners need
• Neutral taste can feel bland to those who prefer fruit flavors

Bottom line: A strong choice for marathoners who want maximum carbohydrate per gel and a flavor-neutral option.

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SiS GO Isotonic Energy Gel, Lemon & Lime, 30 Count

Science in Sport 22g Fast-Acting Liquid Carbohydrate Gel, Instant Energy & Endurance, Natural Flavors, Vegan Sports Nutrition SiS GO Isotonic Energy Gel, 22g Carbs, 2 Fl Oz Gels, Lemon & Lime, 30 Coun

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Best for: High-volume fueling and bulk supply

Runners who train several days a week and go through gels quickly will appreciate the larger count. It suits a consistent fueling routine built around a single, familiar format.

Key specs

• 22g fast-acting carbohydrate per gel
• Isotonic formulation
• 30-count pack

Pros

• Large count reduces restocking frequency
• Lemon and lime is a crisp, less sweet option
• Consistent 22g dose makes intake easy to plan

Cons

• Bigger upfront purchase may not suit occasional runners
• Some runners find citrus flavors harder to tolerate late in a race

Bottom line: Best for regular training blocks where a bulk supply keeps fueling simple.

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SiS GO Isotonic Energy Gel, Orange

SiS GO Isotonic Energy Gel, 22g Carbs, 2 Fl Oz Gels, Orange, 6 Count

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Best for: Familiar flavor for steady training

This is a practical option for runners who want a classic citrus taste they can rely on through training cycles and race week.

Key specs

• 22g carbohydrate per gel
• 2 fl oz gel format
• 6-count pack

Pros

• Orange is a widely liked, familiar flavor
• Small pack allows trying the product before buying in bulk
• Standard 2 fl oz size is easy to carry

Cons

• Six-count pack runs out quickly for high-mileage runners
• Sweetness can feel heavy after several gels in a row

Bottom line: A dependable everyday gel for runners who value a known flavor and a manageable pack size.

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SiS GO Energy + Caffeine Gel, Berry

SiS GO Energy + Caffeine Gel, 22g Carbs, 75mg Caffeine, Berry, 6 Count

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Best for: Caffeine-assisted race efforts

Runners who use caffeine as part of their race strategy and want it delivered alongside carbohydrate in one gel will find this format useful. Those sensitive to caffeine should be cautious.

Key specs

• 22g carbohydrate per gel
• 75mg caffeine per gel
• Berry flavor, 6-count

Pros

• Combines carbohydrate and caffeine in one gel
• Berry flavor is a popular alternative to citrus
• Useful for a planned late-race caffeine dose

Cons

• Caffeine content may be too much for sensitive runners or early training
• Only six per pack, so cost adds up for frequent use

Bottom line: A good choice for experienced runners with a caffeine plan. Those with heart concerns or caffeine sensitivity should consult a doctor first.

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Science in Sport Energy Gel Pack, Tropical Flavor

Science in Sport Energy Gel Pack, SIS Isotonic Energy Gel, 22g Fast Acting Carbs, Performance & Endurance Gels, Tropical Flavor – 2 Fl Oz (Pack of 6)

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Best for: Budget-conscious regular use

This is a sensible pick for runners who want a fast-acting carbohydrate gel for everyday training without committing to a large bulk purchase.

Key specs

• 22g fast-acting carbohydrate per gel
• 2 fl oz gel format
• Pack of six

Pros

• Tropical flavor offers a change from citrus and berry
• Simple, well-known gel format
• Easy to slot into a training week

Cons

• Tropical flavor is not a universal favorite
• Pack size requires frequent reordering for heavy training

Bottom line: A practical, budget-minded pick for runners who want variety without overspending.

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SiS BETA Fuel + Nootropics Energy Gel, Apple

Science in Sport Nootropic Energy Gel with 1:0.8 Maltodextrin to Fructose Ratio & 40g Carbs for Exercise Over 90 Min SiS BETA Fuel + Nootropics Energy Gel, 40g Carbs, Apple, 6 Count

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Best for: Longer efforts needing sustained carbohydrate

Runners doing long training or races who want a higher carbohydrate dose per gel and an apple flavor may find this a good match. The added nootropic ingredients are a separate consideration beyond fueling.

Key specs

• 40g carbohydrate per gel, per the listing name
• Dual-source 1:0.8 maltodextrin to fructose ratio
• Apple flavor, 6-count

Pros

• High carbohydrate dose suits long efforts
• Apple is a mild, approachable flavor
• Dual-source formula matches the BETA Fuel line

Cons

• Nootropic ingredients are not necessary for fueling and may not suit everyone
• Higher carbohydrate dose may cause stomach upset if taken with insufficient fluid

Bottom line: A good option for longer efforts when you want a larger carbohydrate dose in an apple flavor.

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SiS BETA Fuel + Electrolyte Gels, Raspberry & Lemon

Science in Sport Dual-Source Energy Gel with 1:0.8 Maltodextrin to Fructose Ratio, 40g Carbs & Sodium, Exercise Over 90 Min SiS BETA Fuel + Electrolyte Gels, 40g Carbs, Raspberry & Lemon, 30 Count

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Best for: Hot conditions and heavy sweaters

Runners who lose a lot of salt in heat or humidity, or who notice salt crust on their kit, may benefit from a gel that includes sodium alongside carbohydrate.

Key specs

• 40g carbohydrate per gel, per the listing name
• Includes sodium
• Raspberry and lemon flavor, 30-count

Pros

• Sodium helps when sweat losses are high
• Large 30-count pack suits regular training
• Combines fueling and electrolytes in one product

Cons

• Salty-sweet flavor is not for everyone
• Unnecessary if your sweat losses are modest

Bottom line: Ideal for runners in hot climates or heavy sweaters. Anyone with a condition affecting sodium or blood pressure should check with a doctor first.

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Buying Guide

Carbohydrate per gel

Most gels in this range deliver either 22g or 40g of carbohydrate. Higher doses suit efforts over 90 minutes, while 22g is easier to manage in shorter sessions. Check the stated carbohydrate figure against your planned intake, which many coaches set around 30 to 60 grams per hour depending on duration and tolerance.

Good picks for this: Science in Sport Fast-Absorbing Carbohydrate Energy (SiS BETA Fuel Neutral), SiS GO Isotonic Energy Gel, Orange

Carbohydrate type

Dual-source formulas combine glucose-based carbohydrates like maltodextrin with fructose. Manufacturers describe this blend as a way to support higher intake without stomach discomfort. Single-source gels are simpler and often easier on sensitive stomachs.

Good picks for this: SiS BETA Fuel + Nootropics Energy Gel, Apple, Science in Sport Fast-Absorbing Carbohydrate Energy (SiS BETA Fuel Neutral)

Caffeine content

Caffeine can help some runners late in a race, but it is not appropriate for everyone. Check the milligram count and plan your total intake, including coffee and other sources. Test caffeine in training before race day.

Good picks for this: SiS GO Energy + Caffeine Gel, Berry

Sodium and electrolytes

Heavy sweaters and runners in heat often lose meaningful sodium. A gel with added electrolytes can simplify fueling, though plain gels paired with an electrolyte drink are an alternative. Consider your sweat patterns before choosing.

Good picks for this: SiS BETA Fuel + Electrolyte Gels, Raspberry & Lemon

Flavor and texture

Flavor is one of the most personal factors. Neutral and citrus options tend to be easier to tolerate during hard efforts, while fruit flavors like berry or tropical suit some palates better. Sample a flavor in training before committing to a race-day plan.

Good picks for this: SiS GO Isotonic Energy Gel, Lemon & Lime, 30 Count, Science in Sport Energy Gel Pack, Tropical Flavor

Pack size and value

Larger packs reduce the per-gel cost of regular use but require a bigger upfront commitment. Smaller packs let you trial flavors. Estimate how many gels you need per week across your training cycle before choosing a count.

Good picks for this: SiS GO Isotonic Energy Gel, Lemon & Lime, 30 Count, Science in Sport Energy Gel Pack, Tropical Flavor

Packaging and carrying

Standard 2 fl oz gel packets fit most running belts and shorts pockets. Check that the packaging tears easily while running. Practice opening a packet with one hand before race day.

Good picks for this: SiS GO Isotonic Energy Gel, Orange, Science in Sport Energy Gel Pack, Tropical Flavor

FAQ

How many carbs should I take per hour from SiS gels?

Many runners aim for roughly 30 to 60 grams of carbohydrate per hour during efforts longer than 60 to 90 minutes, depending on pace, body size and gut tolerance. Read the carbohydrate figure on each gel and divide your target across the hour. Build up intake gradually in training.

Can I take a gel before running?

Some runners take a gel shortly before a run, but it is generally best to take it during the effort rather than right before starting. Practice this in training to see how your stomach responds.

Do I need to take water with gels?

Most manufacturers recommend taking gels with water to help absorption and reduce stomach discomfort. Sip water with each gel, following the fluid guidance on the packaging.

Is caffeine in gels safe for everyone?

No. Caffeine affects people differently, and some runners should avoid it entirely. If you have a heart condition, high blood pressure, anxiety or are pregnant, speak with a doctor before using caffeinated gels.

Can I use SiS gels for cycling or other sports?

Yes, many endurance athletes use carbohydrate gels across multiple sports. Match your intake to the activity duration and intensity.

How far in advance should I try a new gel?

Try any new gel during a long training run at least a few weeks before race day. This gives you time to notice any stomach reaction and adjust your plan.

Conclusion

For most marathon runners, the Science in Sport Fast-Absorbing Carbohydrate Energy (SiS BETA Fuel Neutral) offers a strong balance of carbohydrate dose and flavor flexibility. Those doing high-volume training may prefer the 30-count SiS GO Lemon & Lime pack. Runners who plan to use caffeine should consider the SiS GO Energy + Caffeine Gel, Berry, while heavy sweaters in hot conditions may find the Electrolyte Gels, Raspberry & Lemon more suitable. Budget-minded runners can start with the Tropical Flavor pack. Trial any option in training before committing to race day.

For more guidance on timing and fueling strategy, see When to Take Energy Gels: A Marathoner's Timing Guide and Energy Gels Before Running: When to Take Them and How Much. Runners weighing gels against other options may also find Energy Chews vs Gels for Running (2026): Which Is Better for Long Runs? useful.

Sources

• Research summaries on carbohydrate intake and endurance performance (nih.gov)
• Guidance on caffeine intake and food labeling in the United States (fda.gov)
• Position stands on nutrition and fluid replacement for exercise (acsm.org)

Related reading

• Top 7 Healthy Energy Gels for Running Worth Considering in 2026

About Lauren Holland

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