Ergogenic Effects of Green Tea Combined with Isolated Soy Protein on Increasing Muscle Mass and Exercise Performance in Resistance-Trained Mice

Abstract

It is well known that supplementation with high protein after exercise can effectively promote muscle synthesis and repair, while green tea is rich in catechins that have antioxidant effects. We aimed to explore the effects of green tea combined with isolated soy protein on increase muscle mass in resistance-trained mice. A total of 32 male ICR mice (8-weeks old) were divided into four groups (n = 8/group), sedentary control group (SC), isolated soy protein with green tea group (ISPG), resistance training group (RT), isolated soy protein and green tea combine with resistance training group (ISPG + RT). All mice received control or ISPG by oral gavage for four consecutive weeks. Forelimb grip and exhaustive swimming time were used for exercise performance evaluation. In biochemical profile, we analyzed lactate, ammonia, blood urea nitrogen (BUN), and glucose and muscle damage index creatine kinase (CK) after exercise as biochemical parameters of exercise fatigue. The grip strength, muscular endurance, and exhaustive swimming time of the ISPG + RT group were significantly increased than other groups (p < 0.05), and also significantly decreased in serum lactate and ammonia levels (p < 0.05, respectively). The ISP + RT group was not only increased in quadriceps weight, (p < 0.05) but also decreased EFP (p < 0.05). We recommend using a 4-week supplementation with ISPG, combined with RT, to increase muscle mass, exercise performance, glycogen storage, and reduce fatigue biochemical parameters after exercise. The benefits of long-term supplementation or application to human supplementation can be further explored in the future.

Keywords: exercise performance; green tea; isolated soy protein; muscle mass; resistance training.

Figure 1

Experimental design.

Figure 2

The effect of ISPG and resistance training on growth curve. Data were mean ± SEM for n = 8 mice per group.

Figure 3

Effect of ISPG and resistance training on (A) absolute forelimb grip strength and (B) relative forelimb grip strength (%). All data are expressed as the mean ± SEM of 8 mice/group. Different superscript letters (a, b, c) above bars are significantly different at p < 0.05. If any letter is the same, it means that the difference between groups is not significant.

Figure 4

Effect of ISPG and resistance training on exhaustive swimming time. Data are expressed as the mean ± SEM of 8 mice/group. Different superscript letters (a, b) above the bar are significantly different at p < 0.05. If any letter is the same, it means that the difference between groups is not significant.

Figure 5

Effect of ISPG and resistance training on (A) muscle strength and (B) muscular endurance test. Data are expressed as the mean ± SEM of 8 mice/group. Different superscript letters (a, b, c) above the bar are significantly different at p < 0.05. If any letter is the same, it means that the difference between groups is not significant.

Figure 6

Effect of ISPG and resistance training on fatigue-related biochemical assessments of serum after 15-min acute exercise. (A) Lactate, (B) NH₃, (C) BUN, (D) CK and (E) glucose. Data are expressed as the mean ± SEM of 8 mice/group. Different superscript letters (a, b, c) above the bar are significantly different at p < 0.05. If any letter is the same, it means that the difference between groups is not significant.

Figure 7

Effect of ISPG and resistance training on (A) hepatic and (B) muscle glycogen level. Data are expressed as the mean ± SEM of 8 mice/group. Different superscript letters (a, b) above the bar are significantly different at p < 0.05. If any letter is the same, it means that the difference between groups is not significant.

Figure 8

Effect of ISPG and RT on histomorphologic features of the (A) liver, (B) gastrocnemius muscle, (C) quadriceps, (D) heart, € kidney, (F) lung, (G) epididymal fay pads, and (H) brown adipose tissue. Specimens were photographed under a light microscope (HE stain, magnification: 200×; bar, 40 μm).