Grip strength meter

HSA^LR and WT mice were split into either sedentary or exercise groups. Exercise groups completed a treadmill exercise training protocol 5 days per week at a 15-degree incline. Animals were placed in the treadmill at rest for 10 min to acclimate followed by 5 min at 6 m/min and then put through a progressive endurance training protocol. In week 1, animals ran at 12 m/min, 720 m total distance; weeks 2–4, 14 m/min, 840 m total distance; weeks 5 and 6, 16 m/min, 980 m total distance; week 7 and 8, 18 m/min, 1080 m total and weeks 9 and 10, animals ran at 20 m/min, totaling 1200 m. Maximum distance run on exhaustive treadmill was measured at weeks 1 and 10 and was determined after 10 min of acclimation at a speed of 6 m/min. The speed was increased by 2 m/min every 2 min until exhaustion defined as the mouse stepping off of the treadmill and standing on an electric shock grid for 5 s. A grip strength meter (Columbus Instruments, Columbus, OH) was used to measure forelimb and all limb grip strength at weeks 1 and 10. As the mouse grasped the bar, the peak pull force in grams was recorded on a digital force transducer. Grip force was standardized to body weight.

Forelimb and hindlimb grip strength were assessed in 7-8 month old female mice using a grip strength meter as previously described (Spurney et al., 2009 ) (Columbus Instruments, Columbus, OH, USA). Mice were acclimated for three consecutive days prior to measurement. An average of five replicates for forelimb and hindlimb was taken for each animal.