Nike Flex Run 2021 Review: Comfort Meets Performance

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Last updated: January 26, 2024

As a seasoned runner, I’m always on the lookout for shoes that promise both comfort and performance. That’s why I was excited to slip my feet into the Nike Flex Run 2021. It’s touted as the go-to sneaker for those who crave flexibility and a lightweight feel during their runs.

I’ve put the Flex Run 2021 through its paces on various terrains, and I’m ready to share my thoughts. Whether you’re a casual jogger or a dedicated marathoner, you’ll want to know how these kicks stack up. Stay tuned as I dive into the nitty-gritty of what makes the Nike Flex Run 2021 a contender—or not—in the crowded field of running shoes.

Design and Appearance

When I first laid eyes on the Nike Flex Run 2021, their sleek design caught my attention. The stylish aesthetics come in a variety of colors, ensuring there’s a look for every runner’s taste. I opted for the classic black with white detailing, but there were several eye-catching hues like electric greens and bold blues available.

The mesh upper isn’t just for show; it’s engineered for breathability and a comfortable fit that adapts to my stride. It wraps snugly around my feet, offering a form-fitting feel without being constrictive. This design feature is particularly important for me during long runs, where comfort is paramount.

Nike’s signature Swoosh is subtly placed, exuding a touch of class without overwhelming the shoes’ design. I appreciate this understated branding; it allows the performance aspects to speak louder than the logo itself. The overall appearance of the Flex Run 2021 exudes a modern vibe, paired seamlessly with practical elements suited to active lifestyles.

Flexibility and Comfort

The Nike Flex Run 2021 is a testament to its name. Flexibility is paramount in these shoes; they boast a specially engineered sole design that promotes natural movement. When I took them for a spin, I immediately noticed the flexibility. My feet moved effortlessly with every stride.

This shoe’s comfort is enhanced by its soft foam midsole which provides a cushioning effect. The long runs turned into a breeze because of this plush support. Here’s a quick breakdown:

  • Soft Foam Midsole: Cushions every step
  • Flexibility: The outsole’s pattern facilitates a natural foot flex

On the topic of comfort, the padded collar and tongue are worth a shout-out. I’ve worn shoes before that rubbed uncomfortably, but that wasn’t the case here. My ankles felt secure, without any chafing or discomfort. Even as I ramped up the miles, my feet stayed comfortable and protected.

It’s clear that the Nike Flex Run 2021 is made with runners’ needs in mind. Durability fused with comfort, I’ve found these shoes are not just for running trails but for navigating the day-to-day hustle with ease.

Performance on Different Terrains

During my runs, I’ve tested the Nike Flex Run 2021 across various terrains. Unsurprisingly, they’ve managed to withstand everything from the abrasive city concrete to the demanding trails of my local park.

Concrete and Asphalt

On city surfaces, the outsole offered excellent traction. The wear and tear after several miles were minimal, hinting at the shoe’s promising longevity.

Track and Field

At the track, the shoes performed admirably. The flexible sole design allowed for a responsive feel, facilitating faster sprints and comfortable pacing.

Nature Trails

When it came to trails, they navigated the terrain confidently. The grooves on the sole adjusted well to uneven ground, providing a stable footfall without compromising flexibility.

My ongoing journey with the Nike Flex Run 2021 continues to impress me. The adaptability to different surfaces confirms their versatile design, making them a strong contender in the running shoe market.

Lightweight and Breathable

While evaluating the Nike Flex Run 2021, I noticed the significant advantage of their lightweight design. The shoes are constructed with materials that prioritize weight reduction, ensuring that each step feels effortless.

Breathability is another key aspect I observed. The upper mesh of the Flex Run 2021 facilitates ample air circulation, which is particularly noticeable on long runs. This keeps my feet cool and reduces moisture build-up, an essential feature for both comfort and foot health.

Ventilation is strategically placed in high-sweat areas, which pairs excellently with the lightweight nature of the shoes, making them an ideal choice for runners who value a fresh and dry experience.

Final Verdict: Pros and Cons

When assessing the Nike Flex Run 2021, it’s clear the pros notably outweigh the cons. In my experience, the comfort level is exceptional, largely due to the Cushlon foam in the midsole. It provides a soft, yet responsive cushioning that adapts to my stride. Moreover, the flexibility of the outsole, with its deep grooves, significantly enhances the natural running motion.

On the flip side, some runners might find the durability of the outsole a bit lacking compared to more rugged models. While it’s perfect for road running, if you often tread rough terrains, you might notice quicker wear and tear.

But what makes the Nike Flex Run 2021 stand out are its lightweight build and breathability, which I’ve found to be a game-changer on longer runs. No longer do I contend with overheating or uncomfortable dampness as the shoe’s design keeps my feet cool and dry.

As for the fit, these shoes ensure a supportive embrace of the foot, thanks to the Flywire cables that integrate with the laces. Although, some with wider feet may wish for a little more room, which is something to consider before purchasing.

In terms of performance, the Flex Run 2021 delivers a solid running experience. The shoes offer ample shock absorption and energy return, which I’ve felt contributes positively to my running efficiency. The grip on various surfaces is reliable too, allowing me to maintain my pace regardless of the conditions.

While I’ve listed some drawbacks, I must say they are minor when placed alongside the benefits. Each run in the Nike Flex Run 2021 feels like a testament to Nike’s commitment to quality and innovation in performance footwear.


I’ve put the Nike Flex Run 2021 to the test and it’s clear they’re a solid choice for runners seeking comfort and performance. They strike an impressive balance between cushioning and responsiveness and their lightweight, breathable design is a game-changer on long runs. While they might not be the best pick for rugged terrain, the benefits they offer make them a standout option. If you’re after a reliable, comfortable running shoe that won’t let you down, the Flex Run 2021 should definitely be on your radar.

Frequently Asked Questions

How comfortable are the Nike Flex Run 2021 running shoes?

The Nike Flex Run 2021 running shoes provide exceptional comfort due to the Cushlon foam in the midsole and a flexible outsole, ensuring a pleasant running experience.

Is the Nike Flex Run 2021 suitable for rough terrains?

The durability of the Nike Flex Run 2021’s outsole may not be sufficient for frequent running on rough terrains, suggesting that they are better suited for smoother surfaces.

Are the Nike Flex Run 2021 shoes breathable and lightweight?

Yes, the Nike Flex Run 2021 shoes are designed to be breathable and lightweight, keeping the feet cool and dry during long runs.

Do the Nike Flex Run 2021 shoes offer a supportive fit?

Yes, they offer a supportive fit thanks to the integration of Flywire cables, but they may feel a bit snug for individuals with wider feet.

How do the Nike Flex Run 2021 perform in terms of shock absorption and grip?

The Nike Flex Run 2021 shoes offer ample shock absorption, energy return, and a reliable grip on various surfaces, allowing for a stable and responsive run.

Would the author recommend the Nike Flex Run 2021 running shoes?

Despite some minor drawbacks, the author recommends the Nike Flex Run 2021, considering them a testament to Nike’s commitment to quality and innovation in performance footwear.