Askew et al. (2011) examined the net cost of locomotion and (unsurprisingly) found it to be much higher when wearing armour than without armour. Interestingly, this cost was greater for walking in armour (2.1 to 2.3 times higher) than running in armour (1.9 times higher). Unfortunately, the sample size for the experiment was very low (4 male subjects), but given that experience wearing Medieval armour was a requirement of the subjects, the small sample size is understandable.
The authors state practical application of their data in interpreting the outcomes of Medieval wars; frankly, I'm more interested in historical changes in fighting styles or movement to compensate for the increased load.
Thanks to The Critical Finch for sending this article to me!
Askew, G. N., Formenti, F., Minetti, A. E., 2011. Limitations imposed by wearing armour on Medieval soldiers’ locomotor performance. Proc. R. Soc. B 2012, 279: 640-644. First published online 20 July 2011. doi: 10.1098/rspb.2011.0816.
Image from Askew et al. (2011)