As the nation endures its longest heatwave in 50 years, many Brits will be reaching for their comfiest and most breathable clothes amid scorching temperatures of 35C.

Yet there is a new weather-friendly fashion trend sweeping the wardrobes of both celebrities and royalty: bright and bold sporty shorts.

When the Princess of Wales finished the gruelling Three Peaks Challenge earlier this month, she opted for the £60 North Face Summit Series Peacesetter 3 shorts in the shade 'Iron Clay'.

The lightweight and breathable shorts soon went on to almost sell out, while royal fans also noted that the shorts were reminiscent of the biker shorts famously favoured by her late mother-in-law, Princess Diana.

But Kate, 44, is also not the first public figure to lean into the 'sporty shorts' trend – with numerous A-listers stepping out in athletic shorts while running their day-to-day errands.

American actress Zoe Kravitz has become the latest to opt for bolder and brighter athletic shorts while out and about, while Zendaya was seen wearing yellow boxer shorts in New York City in May.

And it isn't just women who are embracing the trend – with Harry Styles and Paul Mescal also seen stepping out in colourful micro gym shorts which showcase their casual streetwear style.

According to celebrity stylist Lisa Talbot, sporty shorts 'have become one of this summer's biggest trends' that are 'now being styled for everything from city breaks to lunch with friends'.

'The key to making them look intentional rather than looking as though you’ve forgotten to get changed is all in the styling,' she told The Daily Mail.

Read on to discover the essential do's and dont's for styling sporty shorts this summer and which styles to avoid at all costs...

How NOT to style sporty shorts

1. DON'T: Wear head-to-toe sportswear 

While it may be tempting to lean into the sportswear trend in its entirety, Lisa advises 'avoiding styling sporty shorts with a matching performance T-shirt, running trainers and sports socks'.

'The overall effect can feel more like sports kit than everyday fashion,' she warned. 

'Breaking up the athletic pieces with everyday wardrobe staples creates a much more wearable look.'

2. DON'T: Ignore the length

Micro shorts may be in fashion, but Lisa recommends considering what works best for you when selecting the length of your sporty shorts.

She warned: 'Not every pair of sporty shorts works for every body shape. 

'A style that’s too short can make you feel self-conscious, while an overly long pair can visually shorten the legs. 

'Look for a length that sits comfortably on your upper thigh or just above the knee, depending on what makes you feel your most confident.'

3. DON'T: Forget the fabric

When opting to wear athletic shorts in your day-to-day life, the material and brand is key. 

While some sporty shorts are 'designed purely for performance', these typically come with 'shiny technical fabrics and visible branding that are better suited to workouts'.

'For everyday wear, opt for cleaner finishes, matte fabrics or elevated athletic styles that look more premium and integrate more easily into your existing wardrobe,' she added.

4. DON'T: Assume they suit every occasion

Ultimately, while sporty shorts may be sweeping the wardrobes of A-listers and even the future Queen, they aren't necessarily the perfect item for every case.

'Sporty shorts are perfect for holidays, weekend brunches, sightseeing and casual summer days, but they won’t work everywhere,' warned Lisa.

'Smart restaurants, formal events and many workplaces still call for a more elevated outfit. 

'Knowing when the trend is appropriate is just as important as knowing how to wear it.'

How to make sporty shorts look sophisticated and chic

1. DO: Balance the sporty feel with smarter pieces

Combining more relaxed athletic items with more 'elevated pieces' can create a healthy and desirable 'balance', according to Lisa. 

'A crisp oversized shirt, a structured blazer, a fitted ribbed tank or a fine knit instantly makes them feel more polished,' she added.

'Mixing casual and tailored elements is what gives the outfit a considered feel.'

2. DO: Think about proportions

Traditionally, sporty shorts are 'looser through the leg, so pairing them with a more fitted top helps create shape and definition,' according to Lisa. 

However, it is still possible to pair a sporty short with a more oversized item of clothing.

Lisa explained: 'If you prefer an oversized shirt or sweatshirt, try partially tucking it in or choosing a cropped silhouette to ensure your waistline isn’t completely lost.'

3. DO: Elevate your footwear

As with every outfit, it is crucial that footwear is not forgotten, especially when styling sporty shorts.

Lisa explained: 'One of the easiest ways to make sporty shorts feel more fashionable is through your shoes. 

'Minimal leather trainers, sleek sandals, ballet flats or even loafers instantly take the outfit beyond activewear. 

'Accessories like sunglasses, a crossbody bag or gold jewellery also help finish the look.'

4. DO: Wear colours that complement your wardrobe

With athletic shorts coming in all sorts of colours and varying shades, taking careful consideration of what suits you best is vital. 

Lisa noted: 'Classic shades such as black, navy, olive, cream or chocolate brown are incredibly versatile and can be styled in countless ways. 

'Choosing colours that already work with the rest of your wardrobe means you’ll get far more wear from the trend rather than it becoming a one-season purchase.'

5. DO: Wear them with confidence

Ultimately, as you step out in sporty shorts this summer, the most stylish looks will be those 'worn with confidence'.

Lisa added: 'If you’re constantly adjusting your shorts or worrying they’re too short, too tight or too oversized, they’re probably not the right pair. 

'Finding a style that fits well and feels comfortable will always look more flattering than following a trend that doesn’t feel authentic to you.'