Is Junk Food an Underrated Pre-Workout?

We tested six different snacks, from Oreos to gummy bears, to see if the claims about "junk fuel" are true

April 27, 2024 6:42 am
A bunch of Oreos against a blue background. We tested these snack cookies and other junk foods to see which ones are best as pre-workout fuel.
Oreos fared pretty well in our "junk fuel" rankings. But a different treat took home the top prize.

Candy is a perfectly acceptable pre-workout snack, according to Dwayne “The Rock” Johnson, who has been warming up by lifting king-size Snickers bars to his mouth since he was 14 years old. I wouldn’t want to fight a WWE Superstar on this for obvious reasons, but as it turns out, Johnson does have a point.

Snickers and similar junk food can make decent workout fuel, particularly for people who aren’t going to schedule out eating a protein and complex carbohydrate two to three hours before exercising (which experts say is ideal). For people like me, who are less precise in their eating habits, a simple carbohydrate (like a little chocolate-caramel-nougat candy bar) eaten 30 to 60 minutes before working out can get the job done. 

“While these foods may not typically be associated with a healthy diet, if consumed as part of a balanced eating plan focused on whole foods, lean proteins and minimal added sugars, they can offer a quick source of energy before exercise,” registered dietitian Krista Wale told InsideHook. 

Rice Krispies Treats, Pop-Tarts and other quick-digesting carbs can be similarly helpful for providing energy boosts, Wale explained. That said, these snacks also may leave people feeling full and sluggish, or worse, send them hunting for a public bathroom during a run. Is it worth the risk?

Many trainees think so. Members of the CrossFit community have enthusiastically lauded “junk fuel” on Reddit. In addition to Rice Krispies Treats, Pop-Tarts and Snickers, Oreos, gummy bears and even Goldfish have also been touted as great pre-workout snacks to consider — with the caveat that you must eat nutrient-rich meals after hitting the gym. 

To find out which junk foods are worth keeping in your gym bag, I decided to test them. In my personal experience trying all of these pre-workout guilty-pleasure snacks, the hardest part was not necessarily the workouts themselves. Instead, it was finding the willpower to not house the remaining pan of freshly-made homemade Rice Krispies bars as a post-workout reward. (Predictably, the few times I indulged, I was less interested in a salad and only wanted more sugar.)

Still, I powered through the process — not just for an excuse to buy Pop-Tarts for the first time since the 2000s, but for research. With the help of Wale and other nutrition and fitness experts, I found out how each pre-workout snack stacked up, and found there are three you may seriously want to consider.

The Workout 

Whether sugar comes from fruit or candy, it breaks down to release adenosine triphosphate, or ATP, which is often referred to as “energy currency” by scientists. This energizes muscles for exercise, according to Derek Lipton, a dietitian and certified strength and conditioning coach. “However, the type of exercise does impact the need for these types of snacks,” he noted. For instance, sugar is not necessary before a low-intensity cardio session, like a long walk, or light strength training without any cardio. “But these snacks can provide a significant boost to energy during more intense activities, such as running, biking or a HIIT workout.”

For workouts lasting longer than an hour, Lipton and Wale agreed that individuals may need to eat a complex carbohydrate beforehand, along with a little protein and fiber. Chewing up a handful of almonds can suffice for both of these nutrients, but it’s not nearly as much fun as popping a Pop-Tart.

With all this in mind, I opted to try the following pre-workout snacks before a CorePower Yoga Sculpt class — an hour-long combination of yoga, cardio and strength training with weights, all in a heated room. For the sake of consistency, I performed each workout as close to the start of the day as possible. 

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Despite the endorsement from The Rock, it only took about a minute of warming up to regret eating a Snickers bar 30 minutes before a Sculpt class. Not only was it too much for the first thing in the morning, it was too much in general. I was able to get through the workout, but my stomach felt like a washing machine. Overall, I had a more sluggish and less energetic experience, which defeats the purpose of a pre-workout. 

To Lipton, this makes sense. A standard Snickers bar has 12 grams of fat, “which can be too heavy for most people that close to an intense workout, so it would not make for a great fuel source,” he explained. “This would better serve as a hunger-satisfying snack after a long workout, or at least a few hours before.”

Although The Rock was eating a king-size Snickers before his workouts, and I ate a full-size, a fun-size Snickers likely would’ve been a better way to adjust for not being built like a pro wrestler. Yelena Wheeler, a registered dietitian nutritionist, recommended waiting closer to 60 minutes to workout after eating. “One hour prior to workout is optimal, but I do not believe that it would be a great pre-workout snack.”

Next time, in addition to waiting a little longer to exercise, I would eat half a Snickers before, and save the other half for after. That way it wouldn’t weigh me down, and I’d have something to salivate over between squats. 


Pop-Tarts have one gram of fiber per every two-pack, which can be beneficial for maintaining stamina in a workout, but they are “very high-calorie and fairly high in fat for a pre-workout snack,” Lipton warned. To account for this, I went for the Unfrosted Strawberry Pop-Tarts, which come in on the lower end for calories and sugar than the frosted counterparts. Learning from my Snickers mistakes, I cut the portion in half, only eating one tart about 45 minutes before exercising.

As a nostalgic nod to how I consumed them as a child, I toasted the Pop-Tart to well-done and slathered it with butter. This increased the calories but also added vitamins A and E. These small adjustments made the snack a more palatable pre-workout. I had enough energy to get through class and did not feel weighed down. But by the time I ate my second Tart afterwards, the full serving size felt too heavy for that little nourishment.

“It’s not something I would recommend as a regular pre-workout snack,” Lipton said. Still, for anyone working out for longer than an hour, the convenience of a Pop-Tart on-hand may be slightly better than nothing. “But there are much better options,” he added. As eager as I was to have a reason to introduce Pop-Tarts back into my diet, I have to agree.

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For evidence of the link between eating cookies and getting cut, look no further than Oreo and Chips Ahoy-flavored whey protein. For those who would rather consume a pre-workout that is vaguely vegan, Oreos themselves can be an option, but managing portions is key. Most people can figure out that it’s a bad idea to eat an entire sleeve of cookies before a group workout class, but even snack packs of six Oreos contained more sugar than I needed — over half of the daily recommended amount of added sugar, or 27 grams. 

“Two to three Oreos an hour before a hard workout shouldn’t be an issue,” Lipton said, noting that it’s not the best option for a pre-workout. Unconvinced, I ate three Oreos about 30 minutes before my workout. Compared to the Snickers and Pop-Tarts, Oreos were a lighter snack, and they didn’t lead to an energy crash by the end of class, either. 

While it’s not great for the environment in the long term, having neatly packaged snack packs was similar to Pop-Tarts in terms of convenience. If I were to exercise for more than an hour, these would come in handy. But at that point, a healthier, higher protein snack would make more sense, Wheeler recommended. “It is important to consume a simple carbohydrate in combination with a little bit of protein and fiber prior.”

Next time I would dip my Oreos in coffee, which has been found to be an effective pre-workout beverage. Given the digestive risks, though, that’s an experiment for a home workout. 

Gummy Bears

Like cookie flavoring, gummy bears have giggled their way into wellness culture in recent years, with a number of gummies being developed for the sake of vitamin supplementation. But among bodybuilders, good old-fashioned Haribo bears or any other variety will do the trick. 

“These are simply just another form of easy-to-digest carbs, or sugar, that provide a quick source of energy without making your stomach feel too heavy,” Lipton reiterated. Although gummy candies have gelatin in them, which contains collagen that is important for ligament and tendon strength, Lipton stressed that “the amount found in gummy bears is negligible.”

Nevertheless, I was sold by the “World’s Best” claims of Albanese Gummi Bears and stuck to the nine-bear, 100-calorie portion size first thing in the morning, 30 minutes before a workout. Compared to the previously tested pre-workout snacks, this was the lightest — but it didn’t leave me famished or crashing by the end of the workout, thankfully. Exercising at the start of my day also helped with this, and I would argue that Gummi Bears aren’t the worst breakfast, especially for anyone who is not typically hungry first thing in the morning. 

Based on this experience, I buy gummy candies more regularly for the purposes of a pre-workout snack. If I’m being honest, they are a nice little post-workout treat to keep in the car, but not too much to kill my appetite for something more nutritious once I get home. The only difference is that Gummi Bears were my gateway into other gummies, and how I discovered a truly superior candy: Nerds Gummy Clusters

With 17 pieces per 100-calorie serving, they are comparable to Gummi Bears, and the Nerds don’t really add or take away anything to my workout. But exercise is about improving your mental health as much as your physical health, and discovering a new favorite treat along the way only helps with that. They may not rank number one on the list, but they are now one of my favorite pre-workout snacks.


If sweets are not your thing, don’t worry. It’s still entirely possible to participate in this pre-workout experiment with a savory snack like Goldfish. In fact, these tiny crackers are Lipton’s personal favorite as a pre- and intra-workout snack. “This is a very popular one among my clients, particularly athletes before games and practices,” he said. “Simple, easy-to-digest carbs that provide tasty energy without filling you up.”

Lipton suggested one to two single serving bags about 30 minutes before a workout. I went with one bag, which has 130 calories, three grams of protein and no sugar. Like gummy candies, this was more than enough to sustain an hour-long workout, but I had a second bag afterwards. The individual bags had the convenience of Pop-Tarts, but weren’t as heavy on the calories. In retrospect, I could’ve eaten a full-size bag after my morning workout before even looking at a fruit or vegetable, so the portion containment was appreciated. 

Goldfish felt like a slightly more substantial pre-workout snack than Gummi Bears, without weighing me down like a Snickers bar did. The biggest difference was that the sodium content (10% of the daily recommended amount, to be exact), which left me feeling more dehydrated by the end of my heated workout than the sweet snacks did, despite drinking water throughout.

“One disadvantage of this snack is that it is fairly high in salt which can lead to a need for increased fluid consumption,” Wheeler warned. I would put a little more effort into hydrating before working out with these than I would with other snacks. Those Goldfish need water to swim!

Rice Krispies Treats 

Rice Krispies Treats have received similar wellness hype alongside gummy bears, and they are a favorite among bodybuilders and athletes because “they provide a tasty and convenient source of quick carbs to fuel an intense cardio-based session, such as HIIT or a basketball game,” Lipton explained. They also have a sleek nickname: RKTs. Lipton recommends one to two RKTs about 30 minutes before a workout. 

With the exception of people with enough pastry experience to make a Pop-Tart from scratch, RKTs are the only snack on this list that I could easily make at home. And after examining the list of ingredients on Kellogg’s brand Rice Krispies Treats, I decided to ditch the artificial flavors and monoglycerides and melt my own butter and marshmallows on the stove. 

An eyeballed equivalent of standard-size Rice Krispies Treat was an equally effective pre-workout snack as the Goldfish and Gummi Bears (and Nerds Gummy Clusters). I had enough energy for a morning workout and didn’t feel a steep drop-off in energy post-workout, even as my appetite began to spike. Based on the efficacy as a pre-workout alone, gummy candies, Goldfish crackers and RKTs could be considered in a three-way tie for number one spot. What really differentiates the top three is personal preference. 

My Final Thoughts on the Experiment

When it comes to my general outlook on eating, I prefer to consume simple foods where I can pronounce the ingredients on the label. Marshmallows aren’t exactly whole foods, but eating homemade Rice Krispies Treats from a pan felt healthier compared to a single serving out of a wrapper, even if it required a little more discipline to not eat the entire pan afterwards. 

This process changed my eating habits, not just by introducing me to Nerds Gummy Clusters, but because I now make Rice Krispies Treats with more regularity at home. I’ve found them to be an affordable snack to have around, and one that actually motivates me to work out.

When I think about it, this experiment feels like the exercise equivalent of wrapping medicine in cheese for my dog. Sometimes we have to put a little cherry on top of what’s good for us in order to maintain those healthy habits. And above protein, caffeine and trendy adaptogens, that’s really what I’m looking for in a pre-workout: a little treat for doing what I’m supposed to. 

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