Reduced recovery ratios arise due to irreversible changes in the network during the energy dissipation (e.g., breaking bonds). In certain cases, however, the mechanical history of the sample can be erased by giving it time to rest and relax. For a swift recovery from a potentially cyclical impact, materials that require shorter resting times are preferred. Most commonly, tough hydrogels were given 5-10 minutes to relax between two tensile cycle. The hydrogen bonding networks based on P(VIm-stat-MAAc) exhibited one of the most efficient self-recovering behavior. In the related report, the gel specimen was elongated to ε = 300% before being given 10 minutes to relax at room temperature. Upon a second tensile cycle, the hysteresis recovery reached h r = 91%. The single network made from partially hydrolyzed carboxy methyl chitosan and PAAm reached higher values: after a 2 min recovery period, the hysteresis recovery was h r = 100% when stretched to ε = 500%. The last example of an extremely fast self-recovering gel was represented by the micellar PAAm/DVB hydrogels, where relaxing the hydrogel 3 min at room temperature was sufficient to give a hysteresis recovery of h r = 100% at a strain of ε = 700%. To fully recover (h r = 100%), other tough hydrogels required longer relaxation times, and/or elevated temperatures. Aside from the above works focusing on the fundamentals, tissue engineering remains the most popular area of application for tough hydrogels. This mostly involves testing the gel's in vitro cytocompatibility, in vivo injectability or capacity to act as implants. Two reports envisaged tough hydrogels as skin replacements and have indeed tested their wound healing capacities. For comparative reasons, the papers by Wegst and Ashby as well as Taylor and co-workers are widely cited for the fracture mechanics of soft biological tissues. Wegst and Ashby, however, reported data based on gekko lizard skin (Γ = 0.5-2 kJ/m 2 ), rather than human skin, which was shown to have a fracture energy of Γ = 3.6 kJ/m 2 (stratum corneum). In this regard, the earlier cited work involving the PAAm/CSpolypyrrole gels (Γ = 12 kJ/m 2 , E = 50.1 MPa) reached much higher values than needed. The article by Zhang et al, which also looked into skin wound healing, was in good literature agreement regarding the fracture energy (Γ = 3.25 kJ/m 2 ), yet their tensile modulus (E = 7 kPa) did not match measured values of, for instance, tibial skin grafts (E = 0.3-20 MPa). Additionally, the mechanical properties of skin often vary with skin type, thickness, layer, age and orientation. Consequently, these two cases highlight the complexity of matching synthetic material properties to human tissue and the discrepancies that often arise between them.