[What is a Soft Flask?] A Soft Flask is a water bottle made of soft resin that can be folded up compactly when empty. It's easy to drink from anywhere, anytime, for athletes. It's a foldable soft flask. Since there's no cap to open or close, it's easy to drink from; simply place it in your mouth, chew gently, and sip.
[How to drink from a soft flask] These soft flasks come in three sizes: 500ml, 350ml, and 200ml. Soft flasks are designed to allow you to drink by gently biting the spout and squeezing the bottle. Squeezing the bottle pushes out the water, so you can drink without having to look up.
[Compact Storage] Made with a flexible, soft material that fits snugly in your pocket. The flask compresses as you drink, so you don't have to worry about water splashing or shaking. You can also check the exact amount remaining at a glance. The soft flask's body is made of soft vinyl, so it can be folded up and made compact when empty. When not in use, the soft flask can be stored compactly, so it won't be a burden on your luggage.
[Material] Made with BPA-free, food-grade silicone and durable, flexible TPU (thermoplastic polyurethane). It's harmless, odorless, and highly safe. New bottles may have a slight odor. Before first use, filling the bottle with rice water, green tea, sugar cubes, or vinegar can help reduce the odor. Additionally, cleaning with baking soda is recommended. Suitable temperature: 0-40°C. A dust cover is attached to the spout to prevent stains.
[Soft so it won't hurt your body when you wear it] If you use a hard bottle, it can be hard and cause pain when it touches your body when you use it for a long time. However, the soft flask is soft so it won't hurt your body even if you use it for a long time.
First, for those wondering, "What is a soft flask?", I'd like to explain why soft flasks are a valuable hydration ally for runners. Plastic bottles are probably the most common method of hydration. They can be discarded mid-run and recycled, making them an eco-friendly option. However, when it comes to carrying them, sweat can make them difficult to hold, and the water can slosh around, which can be annoying. Soft flasks are vacuum-sealed bottles that shrink in volume as they lose water. They are made to be as lightweight as plastic bottles. Some brands can also be frozen, making them ideal for running in the hot summer months. Also, placing a plastic bottle in the front pocket of a running bag can sometimes put pressure on ribs, causing pain almost to the point of breaking a bone. Soft flasks, with their soft design, fit gently against the ribs, eliminating painful pressure. I don't recall when soft flasks first became available in Japan, but I believe they began to be chosen by trail runners around 2013 and have become popular ever since.
Soft flasks have quickly overtaken the stronghold of the hydration system that was the mainstream in trail running, and have quickly become the go-to method for hydration in trail running. Of course, there are many good points to hydration systems, so I will write about them separately.
