J Physiol 585.1 Temperature-jump force generation in muscle 277 Ranatunga KW, Coupland ME & Pinniger GJ (2006). Temperature-jump induced force generation in muscle is inhibited during lengthening and enhanced during shortening. J Muscle Res Cell Motil 26, 64. Ranatunga KW & Wylie SR (1983). Temperature-dependent transitions in isometric contractions of rat muscle. J Physiol 339, 87–95. Roots H, Offer GW & Ranatunga KW (2007). Comparison of the tension responses to ramp shortening and lengthening in intact mammalian muscle ﬁbres: crossbridge and non- crossbridge contributions. J Muscle Res Cell Motil 28, 123–139. Smith NP, Barclay CJ & Loiselle DS (2005). The efﬁciency of muscle contraction. Prog Biophys Mol Biol 88, 1–58. Smith GA & Sleep J (2004). Mechanokinetics of rapid tension recovery in muscle: the myosin working stroke is followed by a slower release of phosphate. Biophys J 87, 442–456. Tesi C, Colomo F, Nencini S, Piroddi N & Poggesi C (2000). The effect of inorganic phosphate on force generation in single myoﬁbrils from rabbit skeletal muscle. Biophys J 78, 3081–3092. Woledge R, Curtin NC & Homsher E (1985). Energetic aspects of muscle contraction. Monographs of the Physiological society, No. 41. Academic Press, London. Acknowledgements We thank The Wellcome Trust for support of our research, and Professors Giovanni Cecchi (Florence, Italy) and Mike Geeves (Canterbury) for making useful comments on some early write-ups on the study. Author’s present address G. J. Pinniger: School of Biomedical and Chemical Sciences, The University of Western Australia, Crawley, WA 6009, Australia. C 2007 The Authors. Journal compilation C 2007 The Physiological Society