Juicing is when you take more fruits than you could ever dream of eating at once, put them in a machine and out comes sweet, guilt-free nectar.

It caught the public eye with big firms promoting pure juice diets because it “contains vitamins and minerals”. These companies neglected to tell you about the glycemic index.

Let’s first look at why it’s a problem – sugar. Nature created fruits in a complex package; nutrients, sugar and fibre together. The fibre slows down the digestion and in turn the release of these sugars into your blood stream.

What we’ve done is “hacked” this system. We take the fibre out so that not only is it processed too fast, but we can consume tonnes of it without feeling full. This sugar rush is why it makes you feel so good for a short while.

The ensuing insulin spike is what makes it an unhealthy habit. Repeat servings of it is not good for your health in many ways. Instead, saving insulin sensitivity for your anabolic window around training can be beneficial.

So then you are left wondering… which fruits are the best? There are four things to consider:

Effect on insulin

Different fruits contain different types of sugars – Glucose, Sucrose and Fructose, listed in the order of highest to lowest Glycemic Index, meaning how much they raise your blood sugar levels.

This, in turn, affects the relative insulin response, recorded using its insulin index.

Mornings are when your insulin sensitivity is highest as you haven’t eaten for for at least eight hours. This is when you want to avoid food that causes the greatest insulin response.

Blended bananas are ideal, because blending them keeps the fibre intact. They’re also a fructose-dominant food.

During the day, you want to avoid large quantities of high glucose and sucrose juices. This changes if you’re looking for an intentional insulin spike around training.

It can help shuttle protein to cells and creates an “anabolic” state. Such fruits include grapes, mangoes, pineapple and apricots.

Nitrates

We should be considering other beneficial results of consuming a high density of fruit in liquid form. First is that a few fruits contain nitrates, which your body converts into nitric oxide.

Nitric oxide assists in dilation of blood vessels, which promotes blood flow. This improves exercise performance, lowers blood pressure and increases brain function.

Watermelon is a great source of the amino acid citrulline. Your body converts citrulline to nitric oxide via arganine in your body.

The Vitamin C in citrus fruits like oranges and grapefruits is beneficial in other ways. It doesn’t provide nitrates, but instead increases how well you absorb nitric oxide. Pomegranate is also beneficial to nitric oxide activity and blood flow.

The king though, is beetroot juice. Within as little as 45 minutes, beetroot juice has shown to increase nitric oxide levels by over 20%. This is thanks to it having the highest nitrate concentration of any food.

Polyphenols and in particular, Flavanoids

This is where pomegranate comes into its own. Impressive antioxidant levels are obvious in pomegranate from their vibrant colour. This also applies to most other high-flavanoid fruits.

Berries, citrus fruits and apples also contain high levels of flavonoids, of which quercetin is the most prominent.

Most research on flavanoids focuses on their ability to keep you clear of chronic disease. Their anti-inflammatory abilities can provide protection against exercise-induced muscle damage and oxidative stress.

Bromelain

The last, unsuspecting operator in the equation is Bromelain. An enzyme found only in pineapples. it has slight anti-inflammatory benefits. It is also good for digestion; particularly in digesting protein.

As pineapples are also a high-sucrose fruit, there are extra benefits when consuming protein around your training.

Summary

All things considered, pomegranate offers a great natural combo. It’s also a very expensive juice though, particularly in pure, not-from-concentrate form.

For a budget DIY version, a pineapple-beetroot-citrus combo will tick your health benefits boxes well.

And, if you’re not fixed with your training performance, then try eating whole fruits.

Joompa is a digital platform that facilitates the sourcing and booking of freelance, mobile personal fitness coaches. Available on iOS or via www.joompa.com.my