***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: This study was undertaken to investigate the effects of progressive resistance-training ( PRT ) on plasma oxidative stress and antioxidant enzyme activity in erythrocytes . Twenty male volunteers were r and omly assigned to 2 groups : PRT and control . Blood sample s were collected before and after 8 wk of PRT and analyzed for enzymatic activities of superoxide dismutase ( SOD ) and glutathione peroxidase ( GPx ) in erythrocytes , plasma total antioxidant capacity ( TAC ) , and malondialdehyde concentration ( MDA , an index of lipid per oxida- tion in plasma ) .  Resistance training commenced with 8 exercises on nonconsecutive days for 8 wk at 50 % of estimated 1-repetition maximum ( E1RM ) and reached 80 % E1RM by Week 8 . The results showed that PRT significantly increased erythrocyte SOD activity ( 1,323 ± 212.52 vs. 1,449.9 ± 173.8 U/g Hb , p = .014 ) . Plasma concentration of MDA also decreased ( 5.39 ± 1.7 vs. 3.67.4 ± 0.7 nmol/ml , p = .030 ) , although TAC ( 1.42 ± 0.21 vs. 1.61 ± 0.19 mmol/L , p = .1530 ) and GPx ( 39.87 ± 11.5 vs. 48.18 ± 14.48 U/g Hb , p = .883 ) activity did not undergo any considerable changes . Based on these data , the authors conclude that an 8-wk program of PRT strengthens the defensive system of erythrocytes against free-radical damage and therefore can be applied as a useful approach to alleviate oxidative stress Objective To determine the effect of Tai Chi on oxidative stress in a population of elderly Mexican subjects . Design It was carried out a quasi-experimental study with a sample of 55 healthy subjects r and omly divided into two age-matched groups : ( i ) a  control group with 23 subjects and ( ii ) an experimental group with 32 subjects . The experimental group received daily training in Tai Chi for 50 min . Measurements It was measured before and after 6-month of exercise period : thiobarbituric acid reactive substances ( TBARS ) , total antioxidant status ( TAS ) , superoxide dismutase ( SOD ) , and glutathione peroxidase ( GPx ) . Results It was found that the experimental group exhibited a statistically significant decrease in glucose levels , total cholesterol , low-density lipoprotein cholesterol ( LDLC ) , and systolic blood pressure , as well as an increase in SOD and GPx activity and TAS compared with the control group ( p < 0.05 ) . Conclusions Our findings suggest that the daily practice of Tai Chi is useful for reducing OxS in healthy older adults Prehypertension is associated with reduced conduit artery endothelial function and perturbation of oxidant/antioxidant status . It is unknown whether endothelial dysfunction persists to resistance arteries and whether exercise training affects oxidant/antioxidant balance in young prehypertensives . We examined resistance artery function using venous occlusion plethysmography measurement of forearm ( FBF ) and calf blood flow ( CBF ) at rest and during reactive hyperaemia ( RH ) , as well as lipid peroxidation ( 8-iso-PGF2α ) and antioxidant capacity ( Trolox-equivalent antioxidant capacity ; TEAC ) before and after exercise intervention or time control . Forty-three unmedicated prehypertensive and 15 matched normotensive time controls met screening requirements and participated in the study ( age : 21.1±0.8 years ) . Prehypertensive subjects were r and omly assigned to resistance exercise training ( PHRT ; n=15 ) , endurance exercise training ( PHET ; n=13 ) or time-control groups ( PHTC ; n=15 ) . Treatment groups exercised 3 days per week for 8 weeks . Peak and total FBF were lower in prehypertensives than normotensives ( 12.7±1.2 ml min−1 per100 ml tissue and 89.1±7.7 ml min−1 per 100 ml tissue vs 16.3±1.0 ml min−1 per 100 ml tissue and 123.3±6.4 ml min−1 per 100 ml tissue , respectively ; P<0.05 ) . Peak and total CBF were lower in prehypertensives than normotensives ( 15.3±1.2 ml min−1 per 100 ml tissue and 74±8.3 ml min−1 per 100 ml tissue vs 20.9±1.4 ml min−1 per 100 ml tissue and 107±9.2 ml min−1 per 100 ml tissue , respectively ; P<0.05 ) . PHRT and PHET improved humoral measures of TEAC ( + 24 and + 30 % ) and 8-iso-PGF2α ( −43 and −40 % , respectively ; P⩽0.05 ) . This study provides evidence that young prehypertensives  exhibit reduced resistance artery endothelial function and that short-term ( 8 weeks ) resistance or endurance training are effective in improving resistance artery endothelial function and oxidant/antioxidant balance in young prehypertensives BACKGROUND there have been few population -based , r and omized controlled trials on the effects of strength or endurance training on cardiovascular fitness in older women . OBJECTIVE to study the effects of strength or endurance training on cardiovascular fitness in women aged 76 - 78 years . DESIGN a population -based , r and omized controlled trial . SETTING exercise laboratory in a university faculty of sport and health sciences . SUBJECTS we r and omly assigned 42 medically-screened women aged 76 - 78 years , drawn from the population register to strength ( n=16 ) , endurance ( n=15 ) or control ( n=11 ) groups . METHODS subjects in the two exercise groups performed a supervised , individually tailored 18-week strength or endurance training programme . Controls continued with physical activity at their normal level . RESULTS the strength training group showed an increase in cycle ergometer peak power from 68.1 to 70.3 W ( P=0.035 compared with controls ) . Their peak power per kg body weight increased from 1.02 to 1.05 , while that of the endurance training group increased from 0.91 to 0.93 ( P=0.027 and P=0.049 respectively ) . Peak oxygen uptake increased from 18.1 to 19.7 ml x kg(-1 ) x min(-1 ) in the strength and from 17.1 to 18.2 in the endurance group ( non-significant ) . Six subjects ( 19 % ) in the exercise groups withdrew from the study because of health problems . CONCLUSIONS even with its limitations , the study suggests that the effect of 18-week strength or endurance training on cardiovascular fitness among women aged > /=75 is relatively small . Furthermore , health problems can emerge during training programmes in medically-screened elderly women The purpose of this trial was to determine whether exercise without weight loss would reduce F2-isoprostanes in previously sedentary young women . Participants ( N=319 ) were r and omized to four months of 150min/week aerobic exercise or a control group . Plasma free F2-isoprostanes were measured by gas chromatography-mass spectrometry . Other assessment s included fitness and % body fat . Intervention groups were compared with stratification by quartiles of baseline plasma F2-isoprostane . This stratified comparison was linearly adjusted for baseline plasma F2-isoprostane and we also used baseline plasma F2-isoprostane as a propensity score to balance the intervention . Training result ed in significant improvements in aerobic fitness ( 0.88 METs ) and body fat percent ( 1 % ) in exercisers compared to controls ( p<0.001 ) . The exercise group had significantly higher mean baseline plasma F2-isoprostanes ( 79.1 vs 67.9pg/mL ) than the control group in the highest quartile of baseline plasma F2-isoprostanes . Within this highest quartile , exercise led to a greater decline in plasma F2-isoprostanes ( -20.2±2.5pg/mL ) than control ( -7.4±2.5pg/mL ) ; with adjustment for baseline plasma F2-isoprostanes and in the balanced groups , this difference was reduced but remained significant . Four months of exercise training result ed in significant reductions of systemic oxidative stress only among previously sedentary young women who were in the highest quartile of plasma F2-isoprostanes at baseline ( ≥57pg/mL ) . Our findings indicate that the benefits of aerobic exercise in reducing systemic oxidative stress may be limited to those who present higher baseline levels of plasma F2-isoprostanes OBJECTIVE To assess the effect of a 12-week arm-cranking exercise program on reducing oxidative damage in untrained adults with chronic spinal cord injury ( SCI ) . DESIGN R and omized controlled trial . SETTING Community-based supervised intervention . PARTICIPANTS Male adults with complete SCI at or below the fifth thoracic level ( T5 ) ( N=17 ) volunteered for this study . Participants were r and omly allocated to the intervention ( n=9 ) or control ( n=8 ) group using a concealed method . INTERVENTION A 12-week arm-cranking exercise program , 3 sessions/wk , consisting of warming-up ( 10 - 15min ) followed by a main part in arm-crank ( 20 - 30min [ increasing 2min and 30s every 3wk ] ) at a moderate work intensity of 50 % to 65 % of the heart rate reserve ( starting at 50 % and increasing 5 % every 3 weeks ) and by a cooling-down period ( 5 - 10min ) . MAIN OUTCOME MEASURES Plasmatic levels of total antioxidant status as well as erythrocyte glutathione peroxidase activity were measured . Lipid and protein oxidation were determined as malondialdehyde and carbonyl group levels , respectively . Furthermore , physical fitness and body composition were assessed . RESULTS When compared with baseline results , maximum oxygen consumption was significantly increased ( P=.031 ) , suggesting an improvement in physical fitness in the intervention group . Regarding the antioxidant defense system , it was found that both total antioxidant status ( P=.014 ) and erythrocyte glutathione peroxidase activity ( P=.027 ) were significantly increased at the end of the training program . As a consequence , plasmatic levels of malondialdehyde ( P=.008 ) and carbonyl groups ( P=.022 ) were significantly reduced . CONCLUSION A 12-week arm-cranking exercise program improved the antioxidant defense system in adults with chronic SCI , which may finally attenuate both lipid and protein oxidation in this population Purpose  Rheumatoid arthritis ( RA ) patients display high levels of oxidative stress . Transient exercise-induced increases in oxidative stress are thought to be adaptive in healthy population s. This study investigated the effect of exercise on markers of oxidative stress in RA , following acute exercise and a period of exercise training . Methods Acute exercise study : RA patients ( N = 12 , age : 56 ± 11 ) undertook a bout of exercise ( 30–40 min , 70 % VO2MAX ) , and blood sample s were taken before and after exercise to assess markers of oxidative stress . Training study :  RA patients ( N = 19 , age : 56 ± 10 ) were r and omised into either a control or exercise group , who undertook 3 exercise sessions per week ( 30–40 min @70 % VO2MAX ) for 3 months . Plasma markers of oxidative stress ( protein carbonyls ( PC ) , lipid hydroperoxides ( LOOH ) , 3-nitrotyrosine ( 3-NT ) , total antioxidant capacity ( TAC ) and catalase ( CAT ) activity ) , inflammation ( interleukin-8 ( IL-8 ) and C-reactive protein ( CRP ) ) and nitric oxide metabolites ( NOx ) were assessed before and after training . Results Acute exercise study : Protein carbonyls ( PC ) ( + 18 % ) and NOx ( + 27 % ) were significantly increased following exercise .  Training study : 3-nitrotyrosine ( 3-NT ) decreased ( 2.18 ± 1.78 to 1.10 ± 0.93 μM ) in the exercise group only , alongside increases in aerobic fitness ( 24.45 ± 4.98 to 27.10 ± 4.51 ml/kg/min−1 ) and reductions in disease activity score ( DAS : 3.47 ± 1.17 to 2.88 ± 0.76 ) . PC , LOOH , TAC , IL-8 , CRP and NOx concentrations , and CAT activity were unchanged in both groups . Conclusions Aerobic exercise training did not increase markers of oxidative stress in RA  patients . 3-Nitrotyrosine and disease activity were decreased following exercise training Abstract Exercise can be an effective treatment for  depression . Although the efficacy of exercise is well established , little is 
    Output:
    
Conclusion The pooled analysis revealed that regardless of intensity , volume , type of exercise , and studied population , the antioxidant indicators tended to increase and pro-oxidant indicators tended to decrease after training .
Therefore , we conclude that exercise training seems to induce an antioxidant effect .
Thus , it is suggested that people practice some kind of exercise to balance the redox state , regardless of their health status , to improve health-related outcomes