A cord comprising: a tubular braided sheath of strands having an outer surface, an inner surface, and a central hollow portion defined by the inner surface and having a volume; and a core within the central hollow portion of the tubular braided sheath; the tubular braided sheath comprises strands each having a tensile strength of about 8 cN/dtex or more; when the cord is in a relaxed state, the tubular braided sheath has a substantially cylindrical shape having an outer diameter of from about 20 μm to about 5 mm and a relaxed volume of the central hollow portion, and the core does not fill the relaxed volume of the central hollow portion of the tubular braided sheath; when the cord is in a longitudinal tensioned state, the tubular braided sheath elongates under the longitudinal tension such that a tensioned volume of at least a part of the central hollow portion of the tubular braided sheath is less than the relaxed volume, and the inner surface of the tubular braided sheath of tensioned volume contacts and cinches a surface of the core such that slippage between the core and the tubular braided sheath is reduced; and when in a relaxed state, the tubular braided sheath and core satisfy equation: c / 10 ≤ p / t ≤ c / 2 wherein: c is the number of braid carriers for the braided tubular sheath, p is the pick count per meter of the tubular braided sheath, and t is the twist level of the core in turns per meter. a tubular braided sheath of strands having an outer surface, an inner surface, and a central hollow portion defined by the inner surface and having a volume; and a core within the central hollow portion of the tubular braided sheath; the tubular braided sheath comprises strands each having a tensile strength of about 8 cN/dtex or more; when the cord is in a relaxed state, the tubular braided sheath has a substantially cylindrical shape having an outer diameter of from about 20 μm to about 5 mm and a relaxed volume of the central hollow portion, and the core does not fill the relaxed volume of the central hollow portion of the tubular braided sheath; the tubular braided sheath has a substantially cylindrical shape having an outer diameter of from about 20 μm to about 5 mm and a relaxed volume of the central hollow portion, and the core does not fill the relaxed volume of the central hollow portion of the tubular braided sheath; when the cord is in a longitudinal tensioned state, the tubular braided sheath elongates under the longitudinal tension such that a tensioned volume of at least a part of the central hollow portion of the tubular braided sheath is less than the relaxed volume, and the inner surface of the tubular braided sheath of tensioned volume contacts and cinches a surface of the core such that slippage between the core and the tubular braided sheath is reduced; and the tubular braided sheath elongates under the longitudinal tension such that a tensioned volume of at least a part of the central hollow portion of the tubular braided sheath is less than the relaxed volume, and the inner surface of the tubular braided sheath of tensioned volume contacts and cinches a surface of the core such that slippage between the core and the tubular braided sheath is reduced; and when in a relaxed state, the tubular braided sheath and core satisfy equation: c / 10 ≤ p / t ≤ c / 2 wherein: c is the number of braid carriers for the braided tubular sheath, p is the pick count per meter of the tubular braided sheath, and t is the twist level of the core in turns per meter. c is the number of braid carriers for the braided tubular sheath, p is the pick count per meter of the tubular braided sheath, and t is the twist level of the core in turns per meter.