Linear and daily undulating resistance training periodizations have differential beneficial effects in young sedentary women.

The aim of this randomized controlled study was to verify the impact of a 12-weeks muscular endurance (ME) training of high repetitions (i. e., 15-30) with 2 different periodization models on body composition, maximal strength, muscular endurance and cardiorespiratory fitness. Twenty eight sedentary women aged 20-35 years were randomly assigned to: control (CON) (n=8), linear periodization (LP) (n=10) and daily undulating periodization (DUP) (n=10). LP and DUP models significantly improved body composition, maximal strength and ME. However, no significant changes were detected for cardiorespiratory fitness. LP showed a higher body fat loss (- 12.73%) compared to DUP (- 9.93%) (p=0.049), and systematically higher effect sizes (ES) when compared with DUP for maximal strength and cardiorespiratory fitness parameters (e. g. ES=0.53 for ventilatory threshold). In contrast, DUP exhibited a significantly (p=0.002) greater ME gain (129.43%) compared to LP (70.72%) in bench press, and greater ES in all exercises. It may be suggested that LP performed with a high number of repetitions may be considered an appropriate periodization model for untrained young women that would likely lead to the improvement of body composition and maximum strength performance, whereas DUP is more effective for the development of ME.

Resistance training and glycogen content in ovariectomized rats.

The aim of the present study was to investigate the effects of resistance training on glycogen content and muscle cross-sectional area (CSA) in ovariectomized rats. Wistar rats were divided into: sedentary; ovariectomized sedentary; resistance trained; and ovariectomized resistance trained. In the 12-week resistance training, the animals climbed a 1.1 m vertical ladder, 3 days per week, with 4-8 climbs. Cardiac, liver and muscle glycogen content was determined. After the 12-week resistance training period there was a higher hepatic and muscle glycogen content in the resistance training group compared with the other groups (p<0.01). CSA was higher in soleus for the resistance trained, ovariectomized resistance trained and sedentary compared with ovariectomized sedentary (p<0.05). Ovariectomy attenuated the increase in liver and muscle glycogen content, while soleus muscle cross-sectional area increased with resistance training, even in ovariectomized rats. Resistance training could be an important exercise to increase muscle function in situations of reduced estrogen and progesterone.

Nandrolone inhibits MMP-2 in the left ventricle of rats.

The indiscriminate use of anabolic-androgenic steroids has been shown to induce left ventricular dysfunctions. The main objective of the present study was to investigate the effects of nandrolone decanoate on matrix metalloprotease (MMP-2) activity and protein level in the left ventricle (LV) of rats after 7 weeks of mechanical load exercise. Wistar rats were grouped into: sedentary (S); nandrolone decanoate-treated sedentary (AAS); trained without AAS (T) and trained and treated with AAS (AAST). Exercised groups performed a 7-weeks water-jumping program. Training significantly increased the MMP-2 activity by zymography and the protein level by Western blotting analysis. However, the AAS treatment abolished both the increase in MMP activity and protein level induced by exercise. These results suggest that AAS may impair cardiac tissue remodeling which may lead to the heart malfunction.

Effects of resistance training on matrix metalloproteinase-2 activity and biomechanical and physical properties of bone in ovariectomized and intact rats.

The purpose of this study was to investigate the influence of resistance training on the activity of matrix metalloproteinase (MMP)-2 and bone biomechanical properties in ovariectomized and intact rats. Forty-eight female rats were divided into two distinct groups, ovariectomized (OVX) and intact (Int), which were subdivided into three similar subgroups: sedentary, acute exercise and chronic exercise. Rats performed a resistance training for 12 weeks in which animals climbed a vertical ladder of 1.1 m with weights attached to their tails. Sessions were performed with an interval of 3, 4-9 and 8-12 days scaled dynamic movements of climbing. Biomechanical and physical analyses were performed using a universal testing machine, and MMP-2 activity analysis by zymography. Bone density (BD), mineral density (MD), maximum load and fracture load was reduced in sedentary and acute exercise OVX groups compared with the sedentary intact group (P<0.05); in contrast, chronically trained groups (OVX and Int) showed a significant increase in BD, MD and fracture load compared with all the other groups. MMP-2 activity in chronically trained groups also showed a significant increase, while the sedentary OVX group showed a decrease in MMP-2 activity compared with the intact sedentary group (P<0.05). Our results suggest that the resistance training proposed in our work was efficient in reverting the deleterious effects of ovariectomy on bone tissue, and also produced modeling effects in intact rats. On the other hand, ovariectomy reduced the activity of MMP-2 and produced deleterious effects on bone tissue, mimicking menopause intrinsically.

Acute effect of resistance training volume on hormonal responses in trained men.

AIM: The purpose of this study was to investigate the acute hormonal response to resistance training sessions with different volumes in men. METHODS: Ten recreationally trained men (24.5±7.6 years; 76.2±9.2 kg; 175.6±1.5 cm; 24.5±5.5 kg/m(-2)) participated in the study. All subjects completed two experimental protocols with different volumes. The first protocol consisted of 3 sets at 80% of 6 RM and the second protocol was 3 sets at 80% of 12 RM with 2 minutes rest between sets and exercises, separated by seven days between them. The exercise order used was: barbell bench press, leg press, machine front lat-pull down, leg curl, shoulder abduction and leg extension. The blood variables analyzed were: testosterone, growth hormone (GH), cortisol and testosterone/cortisol ratio (T:C) before (Pre) and immediately after (Post) each exercise session. RESULTS: The intra-groups comparison for testosterone and hGH revealed a significant increase in 80%-6RM and 80%-12RM. Cortisol levels was significantly higher in 80%-12RM and T:C ratio in 80% 6 RM when compared Pre and Post values. Inter-groups comparison showed higher hGH and cortisol levels and lower T:C ratio for 80% 12 RM. There was no statistically significant different between 80%-6RM and 80%-12RM for testosterone. CONCLUSION: The present study confirms that the volume of resistance training can be an important factor in the modulation of acute hormonal responses.

Menopause: highlighting the effects of resistance training.

The increase in lifespan and in the proportion of elderly women has increased the focus on menopause induced physiological alterations. These modifications are associated with the elevated risk of several pathologies such as cardiovascular disease, diabetes, obesity, hypertension, dyslipidemia, non-alcoholic fat liver disease, among others. Because of estrogen levels decline, many tissue and organs (muscular, bone, adipose tissue and liver) are affected. Additionally, body composition suffers important modifications. In this sense, there is a growing body of concern in understanding the physiological mechanisms involved and establishing strategies to prevent and reverse the effects of menopause. The hormone reposition therapy, diet and physical exercise have been recommended. Among the diverse exercise modalities, resistance training is not commonly used as a therapeutic intervention in the treatment of menopause. Thus, the aim of this review was to analyze the physiological alterations on several organs and systems induced by menopause and ovariectomy (experimental model to reproduce menopause), as well as, to study the effects of resistance training in preventing and reverting these modifications. In conclusion, resistance training promotes beneficial effects on several organs and systems, mainly, on muscular, bone and adipose tissue, allowing for a better quality of life in this population.

MMP-2, jumping exercise and nandrolone in skeletal muscle.

Matrix metalloproteinases (MMPs) are crucial to the development and maintenance of healthy tissue. The aim of this study was to investigate MMP-2 activity in gastrocnemius, soleus, extensor digitorium longus (EDL) and tibialis anterior (TA) muscles after exercise associated with an anabolic androgenic steroid (AAS). Wistar rats were grouped into: sedentary (S); sedentary with AAS (AAS); trained without (T) and with (AAST) AAS. Exercised groups performed a 7-week water-jumping program. The exercise increased MMP-2 activity in gastrocnemius and soleus, but not in TA and EDL. The AAS treatment decreased MMP-2 activity of EDL, as compared to the S group, with no effect in gastrocnemius and soleus. The association of AAS and training restored the normal MMP activity of EDL. Training increases tissue turnover in primary motor muscles, which in turn respond differently to AAS treatment. This data may be useful for a better understanding of muscular physiology under AAS use.