Milk product intake, muscle strength, and NFKB methylation

Background Muscle atrophy with aging is closely associated with chronic systemic inflammation and lifestyle-related diseases. In the present study, we assessed whether post-exercise milk product intake during 5-month interval walking training (IWT) enhanced the increase in thigh muscle strength and ameliorated susceptibility to inflammation in older women. Methods Subjects [n = 37, 66±5 (standard deviation) yrs] who had been performing IWT for >6 months participated in this study. They were randomly divided into the following 3 groups: IWT alone (CNT, n = 12), IWT + low-dose post-exercise milk product intake (LD, n = 12; 4 g protein and 3 g carbohydrate) or IWT + a 3-times higher dose of milk product intake than the LD group (HD, n = 13). They were instructed to repeat ≥5 sets of fast and slow walking for 3 min each at ≥70% and 40% peak aerobic capacity for walking, respectively, per day for ≥4 days/week. Results After IWT, thigh muscle strength increased in the HD group (8±2%) more than in the CNT group (-2±3%, P = 0.022), despite similar IWT achievements between the groups (P>0.15). Pyrosequencing analysis using whole blood showed that methylation of NFKB1 and NFKB2, master genes of inflammation, was enhanced in the HD group (29±7% and 44 ±11%, respectively) more than in the CNT group (-20±6% and -10±6%, respectively; P<0.001). Moreover, the genome-wide DNA methylation analysis showed that several inflammation-related genes were hyper-methylated in the HD group compared with that in the CNT group, suggesting greater pro-inflammatory cytokine gene suppression in the HD group. Conclusion HD milk product intake after exercise produced a greater percent increase in thigh muscle strength and NFKB1 and NFKB2 gene methylation during IWT in physically active older women

Effects of Home-Based Interval Walking Training on Thigh Muscle Strength and Aerobic Capacity in Female Total Hip Arthroplasty Patients: A Randomized, Controlled Pilot Study

<div><p></p><p>Due to the reduced physical activity of patients who have undergone total hip arthroplasty (THA), there are no home-based exercise training regimens for preventing muscle atrophy and aerobic capacity impairment in these patients. We examined whether interval walking training (IWT) could prevented these issues. Twenty-eight female patients (∼60 years of age) who had undergone THA more than 2 months prior were randomly divided into IWT (n = 14) and control (CNT, n = 14) groups. The IWT subjects trained at a target of 60 min of fast walking at >70% peak aerobic capacity for walking (O_2peak) per wk for 12 wk, while those in the CNT maintained their previous sedentary life during the same period. We measured the energy expenditure of the daily physical activity, except during sleeping and bathing, every minute and every day during the intervention. We also measured the isometric knee extension (F_EXT) and flexion (F_FLX) forces, O_2peak, and anaerobic threshold during the graded cycling exercise (O_2AT) before and after the intervention. All subjects, except for one in IWT, completed the protocol. F_FLX increased by 23% on the operated side (<i>P</i> = 0.003) and 14% on the non-operated side of IWT (<i>P</i> = 0.006), while it only increased on the operated side of CNT (<i>P</i> = 0.03). The O_2peak and O_2AT in IWT increased by 8% (<i>P</i> = 0.08) and 13% (<i>P</i> = 0.002), respectively, and these changes were significantly higher in the IWT than in CNT group (both, <i>P</i><0.05). In conclusion, IWT might be an effective home-based training regimen for preventing the muscle atrophy from reduced daily physical activity in THA patients.</p><p>Trial Registration</p><p>UMIN-CTR <a href="https://upload.umin.ac.jp/cgi-open-bin/ctr/ctr.cgi?function=history&action=list&type=summary&recptno=R000015361&language=E" target="_blank">UMIN000013172</a></p></div