Thin and stretchy training shirt made of soft, elastic polyester and equipped with thin mesh panels for optimal moisture transport and ventilation. The garment also has a zipper at the neck, thumb holes, sleeve pocket and ergonomically shaped sleeves. Tight fit. The sweater works well as an intermediate layer together with an undergarment in medium cold to cold conditions or only in itself in warmer conditions. Of course, it also works well for everyday use. Not lined or frayed inside.