I'm trying to get an understanding on what's going on with some data of mine. I've attached some plots below. This data is from and accelerometer and gyroscope where I've calculated the global accelerations and velocities (top and bottom plot respectively in each figure). The data is from the arm of someone lifting an item which is increasing in weight, and thus their speed becomes slower as the weight gets heavier. My understanding on what I should see is simple; as weight increases the acceleration and velocity decreases. However, I don't think this is what I'm seeing. This is a light weight. I've put lines where the start and end of the lift begins (I've only highlighted one of four lifts). Notice the amount of time elapsed in both plots and the maximum velocity (black horizontal line) in the bottom plot is around 0.9m/s. Now look at a much heavier weight. Having watched the person perform the task I know they performed it slower, and the elapsed time proves this as it's taken twice as long to perform the task, but the maximum velocity is higher than that of a lighter weight at ~1.2m/s. Have I performed a calculation wrong and what I'm seeing is incorrect, or is it correct and I'm just plain not understanding? I expect the velocity plot to be as wide as it is, as I know the task took longer to perform due to the additional exertion required from the lifter, but I also expected a lower velocity to reflect this. Any help would be appreciated.