With the persistence and patience of a runner, BMAI has been meticulously crafting every detail of its products. Founded just over a year ago, BMAI focuses on creating a domestic internet sports brand. Starting with a dozen running enthusiasts, it provides high-quality professional sports equipment for runners. Although young, BMAI's products have rapidly occupied the market like bamboo shoots after a spring rain, attracting countless running enthusiasts. I am one of them.

First of all, I am honored to participate in this BMAI 42K running shoe review. I am a university student with a height of 182 cm and a weight of 60 kg, with a slim build. I love running, and my regular practice is about 10 km per session, with a pace of 5-6 minutes per kilometer. I have completed several marathons, with a full marathon time of around four hours. Here is my review report.

Seeking breakthroughs, even in packaging. After opening the postal package, I was impressed by the long-lost air cushion packaging, which looked very high-end (see Figure 1). Unlike some shoe manufacturers who use cheap packaging to save costs, BMAI uses exquisite air cushion packaging, which is said to be used for many shoes costing thousands to prevent damage during delivery.

The shoes I received are in BMAI purple, with a pure purple upper, a gray logo frame, and a purple, white, black, and purple sole. They look quite refreshing in this hot summer (see Figure 2). The upper is made of a one-piece PU film and mesh, with black reinforced mesh inside the purple grid. According to the promotional details, this is called a 'seamless film technology with jacquard mesh.' The entire front part of the upper is relatively loose, suitable for most Chinese foot shapes.

The heel's outer side features a '必' character design, which has a strong reflective effect. The inner side has the exclusive full marathon mark '42.195,' which is also reflective, enhancing safety during night runs (see Figure 3). This is the part I am most satisfied with and surprised by. The 42K has the full marathon concept of 42.195 printed on it, symbolizing that the purpose of these shoes is to help runners complete a full marathon better. The laces are 3M reflective and non-slip, preventing them from easily coming undone and improving night running safety.

As for the weight of the shoes, my pair is size 43 (US 9.5), with a total weight of about 750g including the original packaging. Excluding the packaging, a pair of shoes weighs about 650g, and a single shoe weighs about 300g. This is almost the same as the advertised weight (see Figure 4). Compared to the ASICS KAYANO23, known as the king of running shoes, which weighs about 320g per shoe, the 42K is about 20g lighter per shoe, saving about 40g per pair. Scientists have conducted experiments showing that for every 100g reduction in shoe weight, the metabolic rate decreases by 1.11%. This means that if it originally took 4 hours to run a full marathon, under the same conditions, reducing the shoe weight by 100g can shorten the total time by a few minutes, which is significant for improving personal bests.

The BMAI running functional insoles use a dual-density structure, and the craftsmanship is evident from the back, providing effective cushioning and shock absorption (see Figure 5). The good cushioning effect is also due to the sole, with a front sole thickness of about 2.7 cm and a shock-absorbing outsole thickness of about 4.0 cm, providing excellent shock absorption. Whether using the forefoot, full foot, or heel landing running method, the 42K can provide perfect shock absorption. The difference between the front and rear soles is about 1.3 cm, which I believe will also provide a better cushioning experience (see Figure 6).

Haihe East Road is a route I often run, from school to Tianjin Station, a round trip is just about a half marathon (around 22/23 kilometers). Running along the Haihe River, the environment is beautiful, the air is fresh, and there are appropriate slopes for training. Uphill and downhill runs can continuously improve cardiopulmonary function, increase speed, and enhance endurance. Wearing the 42K, I ran along Haihe East Road to Tianjin Station. Through testing, the shock absorption, grip, and balance of these running shoes are excellent, and the reflective performance during night runs is superb, enhancing my running safety. After 15 kilometers, my clothes were almost soaked, but thanks to the good breathability, my feet remained dry, and there was no slipping of the socks. The breathability of these running shoes is excellent, making them very suitable for summer marathons. Personally, I feel these shoes are more suitable for track races, such as marathon competitions. The lightweight and shock absorption of these shoes can save runners' energy and time. However, for long-term mountain marathon training, the performance of these shoes feels slightly weak.

Summary

1. Breathability - 4 points (out of 5): The one-piece design of the upper, combined with seamless film technology, makes the shoes breathable and fitting. However, in hot weather without wind, breathability decreases.

2. Wrap-around fit - 5 points: The high-elastic foam around the foot provides stable coverage. During running, whether on flat roads, elastic rubber surfaces, or uneven gravel roads, the 42K's wrap-around fit has been proven effective, with no foot movement.

3. Shock absorption - 5 points: In several test runs, including uphill and downhill, the 42K's full sole pattern outsole proved to be more than just for looks. Including the role of the running insoles, whether landing on hard roads or uneven gravel roads, the knees and ankles felt very relaxed, with no strong impact, and the foot's bending during push-off was not restricted.

4. Creativity - 5 points: In addition to the perfect combination of the BMAI logo's QR code and Chinese seal carving, the '必' character design of the 42K integrates track elements, and the exclusive full marathon reflective mark '42.195' brings a sense of honor and safety.

As a dedicated full marathon shoe, the BMAI 42K is excellent. Both the wrap-around fit and cushioning shock absorption performance are fully qualified. The extensive reflective design is very user-friendly, as most urban people with fast-paced daytime work can only run at night. Being able to stand out in the crowd not only reflects the runner's dominance but, more importantly, improves safety.

This concludes the BMAI 42K review report. In the future, I will continue to wear them, conquer marathon tracks, and measure 42.195 kilometers with them! Thank you, BMAI! Thank you, Codoon! Thank you, fellow runners!