Detraining and Retraining Effects from a Multicomponent Training Program on the Functional Capacity and Health Profile of Physically Active Prehypertensive Older Women.

BACKGROUND: Resuming a physical exercise program after a period of cessation is common in older women. Monitoring the responses during this detraining (DT) and retraining (RT) may allow us to analyze how the body reacts to an increase and a reduction in physical inactivity. Therefore, we conducted a follow-up training, DT, and RT in prehypertensive older women to analyze the response to these periods. METHODS: Twenty-three prehypertensive older women (EG; 68.3 ± 2.8 years; 1.61 ± 0.44 m) performed 36 weeks of the multicomponent training program (MTP) followed by twelve weeks of DT plus eight weeks of RT. Fifteen prehypertensive older women (CG; 66.3 ± 3.2 years; 1.59 ± 0.37 m) maintained their normal routine. Functional capacity (FC), lipid, and hemodynamic profile were assessed before, during 24 and 36 weeks of the MTP, after 4 and 12 weeks of DT, and after 8 weeks of RT. RESULTS: After 24 weeks of the MTP, only SBP did not improve. Four weeks of DT did not affect lower body strength (30-CS), TC, or GL. Eight weeks of RT improved BP (SBP: -2.52%; ES: 0.36; p < 0.00; DBP: -1.45%; ES: 0.44; p < 0.02), handgrip strength (3.77%; ES: 0.51; p < 0.00), and 30-CS (3.17%; ES: 0.38; p < 0.04) compared with 36 weeks of the MTP. CONCLUSIONS: Eight weeks of RT allowed patients to recover the benefits lost with detraining, which after only four weeks affected them negatively, and the systematic practice of exercise contributed to greater regulation of BP since 24 weeks of the MTP proved not to be enough to promote positive effects of SBP.

Follow-Up of Eight-Weeks Detraining Period after Exercise Program on Health Profiles of Older Women.

BACKGROUND: The multicomponent training program (MTP) is a physical exercise strategy used to combat the sedentary lifestyle in older women (OW). However, periods of interruption in training are common in this population. The aim of our study was to analyze the 8-week MTP effects followed by two, four, and eight weeks of interruption on the lipid profile (LP) and functional capacity (FC) of OW. METHODS: Twenty-one OW (experimental group [EG], 67.6 ± 3.1 years; 1.55 ± 0.35 m) were subjected to an 8-week MTP followed by a detraining period, and 14 OW (control group [CG], 69.4 ± 4.7 years; 1.61 ± 0.26 m) maintained their daily routine. FC (i.e., 30-s chair stand [30-CS], 8-foot up and go [8-FUG], 6-min walk [6-MWT], handgrip strength [HGS], and heart-rate peak during 6-WMT [HRPeak]), total cholesterol (TC) and triglycerides (TG) were assessed before and after MTP and two, four, and eight weeks after MTP. RESULTS: 8-week MTP resulted in higher FC and decreased LP values in EG (p < 0.05); two and four weeks of detraining did not promote changes. After eight weeks of detraining TC (ES: 2.74; p = 0.00), TG (ES: 1.93; p = 0.00), HGS (ES: 0.49, p = 0.00), HRPeak (ES: 1.01, p = 0.00), 6-MWT (ES: 0.54, p = 0.04), and 8-FUG (ES: 1.20, p = 0.01) declined significantly. CONCLUSIONS: Periods of more than four weeks of detraining should be avoided to promote a good quality of life and health in OW. If older people interrupt training for a period longer than four weeks, physical-education professionals must outline specific training strategies to maintain the adaptations acquired with MTP. Future studies should establish these criteria based on ideal training volume, intensity, and frequency.

Effects of Moderate Exercise Training on Cancer-Induced Muscle Wasting.

BACKGROUND: Muscle wasting is a common phenomenon in oncology and seems to be attenuated by exercise training. The aim of this study is to determine the degree of aggressiveness of cancer-induced muscle wasting in two different phenotypic muscles. It will also determine whether exercise training can attenuate this muscle dysfunction. METHODS: Fifty Sprague Dawley rats were randomly assigned to four experimental groups: two breast cancer model groups (sedentary and exercise) and two control groups (sedentary and exercise). Breast cancer was induced by 1-methyl-1-nitrosoureia (MNU). After 35 weeks of endurance training, animals were sacrificed, and gastrocnemius and soleus muscles harvested for morphometric analysis. RESULTS: In sedentary tumor-bearing animals, a significant reduction in cross-sectional area was found in both muscles (p < 0.05). Interstitial fibrosis was significantly higher in the gastrocnemius muscle of the sedentary tumor-bearing animals (p < 0.05), but not in the soleus muscle. In the gastrocnemius of sedentary tumor-bearing animals, a shift from large to small fibers was observed. This cancer-related muscle dysfunction was prevented by long-term exercise training. CONCLUSIONS: In sedentary animals with tumors, the gastrocnemius muscle showed a very pronounced reduction in cross-sectional area and a marked degree of interstitial fibrosis. There was no difference in collagen deposition between tumor groups, and the soleus muscle showed a less pronounced but significant reduction in cross-sectional area. These contrasting results confirm that cancer-induced muscle wasting can affect specific types of fibers and specific muscles, namely fast glycolytic muscles, and that exercise training can be used to improve it.

Exercise Training-induced Modulation in Microenvironment of Rat Mammary Neoplasms.

Despite the importance attributed to exercise training in the breast cancer (BC) continuum, the underlying mechanisms modulating tumor behavior are unknown. We evaluated the effects of long-term moderate-exercise in the development of mammary tumors, and studied the microenvironment of infiltrative lesions, the amount of connective tissue, and balance between cellular proliferation/death.Fifty Sprague-Dawley rats, randomly assigned into four groups: two control groups (sedentary and exercised) and two models of BC groups (sedentary and exercised) induced by N-methyl-N-nitrosoureia (MNU), were sacrificed after 35 weeks of moderate-exercise, and all perceptible tumors were removed for histological and immunohistochemistry analysis.The median number of infiltrative-lesions per animal was lower in the MNU exercised animals (p=0.02). More than one histological pattern was identified, and papillary carcinoma was the most frequent in both groups. Within infiltrative-lesions, the number of immunopositive cells per µm2 of Ki67 was lower in exercised animals (p=0.002). This presents increased cell death per µm2 (p=0.019). Tumors from sedentary animals had a higher expression of collagen deposition (p=0.027).Long-term moderate-exercise has beneficial effects in tumor development with a diminished prevalence of malignancy. Within infiltrative-lesions, moderate-exercise improves the balance between cell-proliferation and cell-death with decreased connective tissue that suggests lower tumor aggressiveness.

Efficacy of Exercise on Breast Cancer Outcomes: A Systematic Review and Meta-analysis of Preclinical Data.

The use of preclinical models to investigate antitumor effects of exercise on breast tumor (BT) development and progression are critical. However, published results have not been quantitatively summarized or examined for potential exercise-moderating variables. We conducted this review to summarize and quantify the effect-size of exercise on BT outcomes in preclinical studies. A literature search was performed in MEDLINE, PubMed, Web of Science and System for Information on Grey Literature in Europe (SIGLE) databases. Risk of bias was assessed using SYRCLE's RoB tool. A total of 116 correlations were performed to analyze 28 preclinical studies published through December 2016, which included 2,085 animals and 51 exercise programs. Positive effects of small, medium and large magnitude were observed in tumor incidence, growth and multiplicity, respectively. In the tumor microenvironment, positive effects of large magnitude were also observed in proliferation and apoptosis but not in angiogenesis. Moderator variables correlated with higher intervention effects were identified along with a considerable heterogeneity in exercise protocols that precluded us from clearly perceiving the benefits of exercise exposure. In conclusion, exercise performed under specific conditions benefits BT outcomes. Preclinical studies with exercise designs mimicking exercise exposure that can be used in clinical contexts are needed.