The science behind DETOX or JUICING DIETS

By Jules Kirkpatrick, MS

Summer is here! That means vacations, eating out, and lots of ice cream. When you fall off your normal eating habits, many female athletes may consider a detox diet or a juice cleanse to help eliminate those vacation “toxins” and lose a couple LBs.

But what is the actual science behind this? Are detox diets & juice cleanses a good idea for female athletes?

This article helps provide you with the FACTS.

Does this sound familiar to you?

You just came back from your summer vacation with the fam. An entire week of sitting on the beach, eating and drinking whatever, no time for the gym.

It was your first week all year without running around to sports practice and games – ahhhh, so nice.

However, it was ALSO a week filled with fried food, no vegetables to be seen, and sleep in the sun.

Now you’re feeling bloated and pretty much just….“blehhhh”. Vacation time is over and you don’t want to see any more pizza and ice cream; you need to get back to training and your body feels like it needs a large cleansing to flush out all those vacation TOXINS.

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Speaking of which… might a cleanse just do the trick?

So you quickly Google search: “Detox Diet”

Perfect, you find: ‘Lemon Detox Diet’ which consists of 1-2 weeks of:

  1. Lemon juice

  2. Water

  3. Cayenne pepper

  4. Tree syrup

  5. Laxative tea & sea salt water


Ok so how does this whole lemon detox thing work??

Well, Lemon Detox’s website says that the cayenne pepper will ensure your “body’s metabolism is still optimal during the cleanse” and that “the lemon juice acts as a detergent, cleaning your inner organs.”

Okay…  then it also says that the laxative tea and sea salt water will “trigger the elimination process.”

Honestly, it does sounds like a legitimate way to get rid of the post-vacation bloat and all the toxins floating around in your cells, right?

But let’s ask ourselves one more question before we jump into whether these juicing and detox diets actually work:

WHAT toxins need to be eliminated?

Before starting a new diet, we probably need to know what toxins the juice and detox cleanses will get rid of…

BUT, it doesn’t look like any of these companies tell us that information – interesting.

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Well, we don’t know what toxins are actually being eliminated, but let’s assume the benefit of the doubt.

The cleanse will get rid of SOME toxins… right?

Not necessarily! Our body has a natural cleaning mechanism - the liver - that removes toxins for us!

Unfortunately, juicing and detox diets do not expedite this process, and there is ZERO research that supports the effectiveness of these diets to “detoxify” our system!

Lucky for us, we do not NEED any special detoxification interventions to help expedite the process! Our liver does the job!!

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Well, if the detoxes and juice cleanses aren’t great at eliminating toxins….

What about weight loss?

Detox or juicing diets are short-term (less than a month) nutritional interventions that are typically all liquid, and often a mixture of juices and supplements.

IN OTHER WORDS: Do they help you lose weight?

Yes……but WHY?

  • Depletion of glycogen stores due to low carbohydrate intake (glycogen is stored along with water in the muscle and liver)

  • ALL liquid diet (less food in sitting in your GI track)

  • Extremely low-calorie


BUT, do they provide long-lasting results?

Read on!

The Detoxing Athlete: THE SCIENCE

Let’s refer back to the Lemon Detox Diet and take a look at the ingredients: lemons, water, a sprinkle of pepper, and a few carbs from tree syrup.

Next, let’s think about what your body needs for your SPORT.


Maybe you’re a soccer player playing on a club team over the summer to keep your skills sharp; plus, you can get ahead of the curve for your upcoming fall season.

Club practice over the summer isn’t a HUGE commitment, but let’s say it’s 10 hours during the week through a combination of practice and some games here and there.

We’re looking at multiple hours of sprinting, jogging, cutting, headers, and hours on the field in the hot summer sun.

Time for recovery. Hello lemons, water, pepper, and tree syrup….?

NEWS ALERT: This is not the recipe for success!

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The life of an ATHLETE requires copious amount of work alongside of challenging physical and psychological demands. These demands are fueled through adequate consumption of carbohydrates, proteins, and fats.

Lets start talking facts shall we?

TRUE: High intensity performances are fueled by carbohydrates.

Performing at the most efficient level requires premium gas for premium performance. Carbohydrates are KING for high levels of sports performance and sustained energy to take you through your game without hitting that sluggish wall!

FALSE: High intensity performance is fueled by a combination of lemons, water, and pepper.

Imagine this: you want to do a detox diet for just a few days, and maybe lose a few pounds!

Day 1: You have a HARD practice that’s pretty intense and is 2 hours long but, you made a commitment and decide to drink your detox juice throughout the day.

Day 2 rolls around: You feel a little sluggish but you’re still feeling pretty good for practice. Soccer practice is an hour and a half long at a moderate intensity.

Day 3: You wake up and feel like you’ve been hit by a bus. Your legs are heavy and everything feels a little bit achy.


ANY time you’re putting in work on the field or court, you’re chipping through your energy stores!!!

Your gas tanks (muscle and liver glycogen) are not going to magically going to fill themselves. This means we are left to our own devices (proper nutritional choices) to keep our energy supplies full!

Unfortunately, tree syrup is not going to suffice.

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TRUE: Rigorous training requires adequate protein consumption to repair damaged muscle, grow muscle, and support the recovery process.

FALSE: Detox and juicing diets contain enough protein to meet the physiological demands of an athlete.

Muscle is an expensive investment for your body! While it’s a main driver of sports performance, it doesn’t want to stick around on its own!

Muscle maintenance – not to mention development - takes work, including proper training and nutrition practices!

Unfortunately, the majority of detox diets don’t have enough protein to support muscle growth, repair, and recovery.


TRUE: Adequate caloric and micronutrient intake is required to regulate hormonal function, anabolic (muscle building) processes, and normal day-to-day activities.

FALSE: Detox or juicing diets can provide adequate calories and much needed micronutrients!

While many detox and juicing diets do contain healthy ingredients and micronutrients, it’s difficult to get ALL your micronutrient needs AND enough calories to survive (perform, recover, & improve from) hard training sessions.

It’s not uncommon for some of these diets to contain less than 400 calories a day, which makes it extremely difficult to get an appropriate amount of calories to support athlete demands, as well as necessary micronutrients for health such as fiber and phytonutrients.

To put it in perspective, the number of calories it takes to support general physiological function (NOT including sports practice and lifting) is well above 1,000 calories!

So back to the original question:

Do detox and juicing diets provide LONG lasting results?

No way! These types of diets often lack the prerequisites for health, not to mention the physiological demands of a bada** ATHLETE.

Remember, too little food means decreased performance, decreased recovery, and increased risk of injury!!!

In other words, you might jump on the scale and have lost a pound or two from eating less food than normal AND depleting your energy stores (goodbye water weight), however, this weight will most likely return when you go back to your normal eating schedule.

Is it worth it? …. Think twice!

Sustainable weight loss requires a well-rounded diet to maximize recovery and performance which becomes nearly impossible at the extreme ends of the spectrum!  



  1. Anzenbacher, P., & Anzenbacherová, E. (2001). Cytochromes P450 and metabolism of xenobiotics: Cellular and Molecular Life Sciences, 58(5), 737–747.

  2. Herbold, N. H., & Mulvaney, A. L. (2014). A Survey of Attitudes and Use of Detoxification and Cleanse Diets by Registered Dietitians. Journal of the Academy of Nutrition and Dietetics, 114(9), A38.

  3. Hyson, D. A. (2015). A Review and Critical Analysis of the Scientific Literature Related to 100% Fruit Juice and Human Health12. Advances in Nutrition, 6(1), 37–51.

  4. Klein, A. V., & Kiat, H. (2015). Detox diets for toxin elimination and weight management: a critical review of the evidence. Journal of Human Nutrition and Dietetics, 28(6), 675–686.

  5. Obert, J., Pearlman, M., Obert, L., & Chapin, S. (2017). Popular Weight Loss Strategies: a Review of Four Weight Loss Techniques. Current Gastroenterology Reports, 19(12).


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Julia holds a M.S. in Sports Science and Coach Education from East Tennessee State University and a B.S. in Kinesiology with a concentration in Exercise Science from Temple University. During her time at ETSU, Julia worked as the Assistant Strength and Conditioning Coach for the Women’s D1 Volleyball team and headed their sports nutrition. She also worked as the Head Strength and Conditioning Coach at a local college in Tennessee for their Track & Field team.

Julia’s main passion is bringing an evidence-based approach to training and nutrition practice. Her time spent around collegiate athletes highlighted the gap between real-world practice/understanding and science; enter Relentless Athletics. After working with a variety of athletes and online diet clients, Julia knew there was a hole that needed to be filled – specifically for females. She saw that there was an absence of reliable sources for these individuals to gather information to help develop their athletic ability. Relentless offered the perfect community for Julia to spread her knowledge and help build STRONG foundations for females through nutrition education and training.

In her free time, Julia competes in powerlifting and weightlifter recreationally. She holds the Pennsylvania Junior State Record in the bench press in the 72 kg weight class.