Fig. 2. (A) Schematic of stress–strain behavior observed when a specimen is cycled to increasingly larger strains. The tips of the extension–retraction loops trace a path that closely approximates the curve from a pull-to-break test. In this example, the pull-to-break curve is `r-shaped'. Resilience at a strain level is taken as the ratio of area under the corresponding retraction curve to total area under the broken pull-to-break curve. For instance, for the strain level indicated by `Strain 1', resilience is the ratio of the hatched area to the total area under the pull-to-break curve up to `Strain 1'. (B) Experimental cycling behavior for M. flaccida. For clarity, only the retraction portions of loops (return curves) are shown. The bold line represents the reconstructed pull-to-break extension curve, which is gently `J-shaped'. Resilience (R) at four strain levels is shown.