Running sleds are often very similar to one another at first glance, so it may be necessary to do some comparison shopping for the best running sled before purchasing one. Most of the time, any running sled is shaped similarly to other running sleds, so the differences will come down to the durability of the sled, the amount of weight it can hold, and the attachments it has. Occasionally, different running sleds have slightly different sizes and angles that may make a noticeable difference, so individuals should ideally set up the sleds and harnesses and give them a test pull to see if it feels comfortable before buying.
A well-constructed running sled usually works best if it is made out of steel or some other kind of hard metal. Plastic and wood sleds will not only be less durable, but they also are less likely to slide smoothly over the ground, making the workout much more frustrating. With enough uses, a running sled will sustain some damage to the underside where the sled slides across the ground, so when purchasing a used running sled, make sure to examine this area thoroughly. Also ensure that the post that holds the weights securely onto the platform of the sled is still attached firmly and not structurally damaged. Individuals who already own weight plates or who are buying weight plates separately from the sled should check the post to make sure it has the correct diameter to hold the weight plates securely.
Differently constructed sleds will often recommend a different weight limit, both so the sled will not become damaged and for the safety of the user. Beginners might not have a preference on how much weight the sled can carry, but very strong, advanced users should make sure the weight limit is high enough for them to be challenged during the workouts. There should also be enough room to make progress to higher weights eventually.
If using harnesses, clips, and straps from another sled, also make sure that these are rated for the same weight limit as the rest of the sled, because they may break and become dangerous to the user. Some sleds come with a variety of attachments, while others require users to purchase the attachments separately. Users may do some research and decide to buy a specific kind of attachment separately, even if others are provided with the sled. This can provide greater workout variety and intensity, as well as increased comfort for the user.