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Signal Amplification By Reversible Exchange in SHield Enabled Alignment Transfer (SABRE‐SHEATH) is investigated to achieve rapid hyperpolarization of¹³C₁spins of [1‐¹³C]pyruvate, using parahydrogen as the source of nuclear spin order. Pyruvate exchange with an iridium polarization transfer complex can be modulated via a sensitive interplay between temperature and co‐ligation of DMSO and H₂O. Order‐unity¹³C (>50 %) polarization of catalyst‐bound [1‐¹³C]pyruvate is achieved in less than 30 s by restricting the chemical exchange of [1‐¹³C]pyruvate at lower temperatures. On the catalyst bound pyruvate, 39 % polarization is measured using a 1.4 T NMR spectrometer, and extrapolated to >50 % at the end of build‐up in situ. The highest measured polarization of a 30‐mM pyruvate sample, including free and bound pyruvate is 13 % when using 20 mM DMSO and 0.5 M water in CD₃OD. Efficient¹³C polarization is also enabled by favorable relaxation dynamics in sub‐microtesla magnetic fields, as indicated by fast polarization buildup rates compared to theT₁spin‐relaxation rates (e. g., ∼0.2 s⁻¹versus ∼0.1 s⁻¹, respectively, for a 6 mM catalyst‐[1‐¹³C]pyruvate sample). Finally, the catalyst‐bound hyperpolarized [1‐¹³C]pyruvate can be released rapidly by cycling the temperature and/or by optimizing the amount of water, paving the way to future biomedical applications of hyperpolarized [1‐¹³C]pyruvate produced via comparatively fast and simple SABRE‐SHEATH‐based approaches.