Resistance Training.

This research investigated the relationship between exercise training and
cathepsin B expression in the 3xTg-AD murine model of Alzheimer’s disease. 3xTg-AD
mice were assigned to control (Tg, n=10), aerobic training (Tg+AT, n=10), or resistance
training (Tg+RT, n=10). RotaRod peak latency and grip strength were assessed as preand
post-measurements. Skeletal muscle was collected after training and analyzed for
cathepsin B protein. Tg+RT showed greater grip strength than Tg and Tg+AT at posttesting
(p ≤ 0.05). Only Tg+AT showed an improvement in RotaRod peak latency (p ≤
0.05). Gastrocnemius weight was greater in Tg+RT compared to Tg (p ≤ 0.05), and no
differences were observed in cathepsin B or procathepsin B expression (p > 0.05). This
data suggests that cathepsin B was not induced by either mode of exercise training,
however, physical function and muscle mass were improved, therefore inclusion of both
training modalities may address peripheral comorbidities in Alzheimer’s disease.

The primary purpose of this study was to investigate the effects of aerobic and
resistance training on BDNF and IGF-I expression in a 3xTg-AD mouse model of
Alzheimer’s disease. Twenty-four 3xTg-AD mice were randomly assigned to either an
aerobic (AT, n=8), resistance (RT, n=8), or control (CNT, n=8) group. Intervention
groups underwent 9 weeks of exercise training. Motor behavior and grip strength were
measured pre- and post- intervention. Our results showed a significant increase in
hippocampal BDNF expression in AT mice after a 9-week intervention. Further, AT mice
were found to have higher concentrations of IGF-I, and improved motor behavior when
compared to RT and CNT. No significant differences were observed in IGF-I
concentration between RT and other groups. RT improved grip strength after nine weeks
of training. These findings support the use of AT and RT as a tool to improve
comorbidities found in Alzheimer’s disease.

This research examined the time-course of muscle damage in the squat, bench
press, and deadlift. Ten resistance-trained males performed four sets to failure with 80%
of one-repetition maximum (1RM) for each exercise on three separate weeks. Swelling,
range of motion (ROM), delayed onset muscle soreness (DOMS), lactate dehydrogenase
(LDH), creatine kinase (CK), and average concentric velocity (ACV) were assessed pretraining
and at five timepoints post-training: -0, 24, 48, 72, and 96 hours. Swelling
(p<0.01) increased immediately post-training, and DOMS (p<0.01) increased at 24 hours
post-training in the bench press condition. Additionally, DOMS increased at 48 hours in
both squat and deadlift conditions (p<0.01). Squat and deadlift elevated CK immediately
post-training (p<0.01), but LDH only increased in the squat post-training. Immediately
post in the bench press ACV was decreased (p<0.01) along with in the squat for up to 72
hours (p<0.01), however, ACV did not change following the deadlift (p>0.05).