We examined the effects of endurance training with chronic pre-exercise concentrated Kurozu (black vinegar) supplementation on mitochondrial enzyme activity and energy metabolism in Institute of Cancer Research (ICR) mice. Mice were divided into a control group, an endurance training group, and an endurance training + concentrated Kurozu supplementation group. Mice were orally supplemented with water or concentrated Kurozu solution (500 mg/kg body weight/day) for 3 weeks. The mice in the training group were subjected to exercise on a treadmill (20–25 m/min × 30 min, five times/week) starting 30 min after the supplementation. The maximal activity of citrate synthase in the plantaris muscle in the endurance training + concentrated Kurozu supplementation group was significantly higher than that in the control group (p < 0.01). The maximal activity of β-hydroxyacyl coenzyme dehydrogenase (β-HAD) in the soleus muscle in the endurance training + concentrated Kurozu supplementation group was significantly higher than that in the other two groups (p < 0.05 for both). In the final week, significant negative correlation between blood lactate concentration after exercise and soleus β-HAD activity was observed. These findings suggest that endurance training with concentrated Kurozu supplementation increases mitochondrial enzyme activity and might enhance lipid metabolism during exercise.

The aim of this study was to elucidate the effects of oral administration of S-nitrosoglutathione (GSNO), a nitric oxide donor, on force production and Ca²⁺ regulatory proteins in fast-twitch muscles subjected to eccentric contraction (ECC). Rats were administered 1 mmol kg^-1 d^-1 GSNO for five days before ECC. Force production, sarcoplasmic reticulum (SR) Ca²⁺-ATPase activity, and amounts of Ca²⁺ regulatory proteins were examined after 200 ECC repetitions. Three days after ECC, the experimental extensor digitorum longus muscles and the contralateral resting muscles were quickly excised and used for the experiment. Force production at 20 Hz returned to resting levels in GSNO-treated muscles, but not in resting muscles. Western blot analysis showed that GSNO ingestion inhibited ECC-induced loss of ryanodine receptor (RyR) 1 responsible for SR Ca²⁺ release capacity. Overall, these findings indicate that oral administration of a nitric oxide donor prior to ECC can promote force recovery following ECC and suggest that this benefit may be due to inhibition of RyR proteolysis.

This study aimed to investigate whether the implementation of a frailty prevention program using remote assistance combined with face-to-face guidance or solely through a remote assistance method is effective for community-dwelling Japanese older adults. Forty-nine community-dwelling older adults (16 men, age: 70.0 ± 4.8 years) were classified into the following three groups: remote plus face-to-face guidance group (RFGG; n = 17), remote guidance group (RGG; n = 17), and control group (CG; n = 15). The RFGG performed face-to-face supervised strength training once a week for the first 4 weeks, plus similar exercises once a week at home, followed by 8 weeks of performing the same exercises twice a week at home while watching an instructional digital versatile disc (DVD) for a total of 12 weeks. They received one face-to-face nutritional guidance session, followed by guidance over the telephone once a month for 3 months. The RGG performed the same exercises at home while watching the DVD twice weekly and received nutritional guidance over the telephone once a month for 3 months (12 weeks). Only pre- and post-intervention surveys in the CG were conducted. When compared to pre-intervention measurements, RFGG lean body mass, lower limb muscle mass, and grip strength increased significantly, while fat mass percentage decreased significantly (p < 0.05). In the RGG, no significant changes were observed in the physical characteristics. These results suggest that a frailty prevention program not only using a remote guidance but also combined with a face-to-face guidance may be effective for older adults.