Age-related declines in maximal aerobic capacity in regularly exercising vs. sedentary women: a meta-analysis
Margaret D. Fitzgerald 1 , Hirofumi Tanaka 1 , Zung V. Tran 2 , and Douglas R. Seals 1 , 3 1 Human Cardiovascular Research Laboratory, Center for Physical Activity, Disease Prevention, and Aging, Department of Kinesiology, University of Colorado, Boulder 80309; 2 Center for Research in Ambulatory...
Gespeichert in:
| Veröffentlicht in: | Journal of applied physiology (1985) 1997-07, Vol.83 (1), p.160-165 |
|---|---|
| Hauptverfasser: | , , , |
| Format: | Artikel |
| Sprache: | eng |
| Schlagworte: | |
| Online-Zugang: | Volltext |
| Tags: |
Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
|
| container_end_page | 165 |
|---|---|
| container_issue | 1 |
| container_start_page | 160 |
| container_title | Journal of applied physiology (1985) |
| container_volume | 83 |
| creator | Fitzgerald, Margaret D Tanaka, Hirofumi Tran, Zung V Seals, Douglas R |
| description | Margaret D.
Fitzgerald 1 ,
Hirofumi
Tanaka 1 ,
Zung V.
Tran 2 , and
Douglas R.
Seals 1 , 3
1 Human Cardiovascular Research
Laboratory, Center for Physical Activity, Disease Prevention, and
Aging, Department of Kinesiology, University of Colorado, Boulder
80309; 2 Center for Research
in Ambulatory Health Care Administration, Medical Group Management
Association, Englewood 80112; and
3 Divisions of Cardiology and
Geriatric Medicine, Department of Medicine, University of Colorado
Health Sciences Center, Denver, Colorado 80262
Received 16 September 1996; accepted in final form 12 March 1997.
Fitzgerald, Margaret D., Hirofumi Tanaka, Zung V. Tran, and
Douglas R. Seals. Age-related declines in maximal aerobic capacity
in regularly exercising vs. sedentary women: a meta-analysis. J. Appl. Physiol. 83(1): 160-165, 1997. Our purpose was to determine the relationship between habitual
aerobic exercise status and the rate of decline in maximal aerobic
capacity across the adult age range in women. A meta-analytic approach
was used in which mean maximal oxygen consumption
( O 2 max ) values from
female subject groups (ages 18-89 yr) were obtained from the
published literature. A total of 239 subject groups from 109 studies
involving 4,884 subjects met the inclusion criteria and were
arbitrarily separated into sedentary (groups = 107; subjects = 2,256),
active (groups = 69; subjects = 1,717), and endurance-trained (groups = 63; subjects = 911) populations.
O 2 max averaged 29.7 ± 7.8, 38.7 ± 9.2, and 52.0 ± 10.5 ml · kg 1 · min 1 ,
respectively, and was inversely related to age within each population ( r = 0.82 to 0.87, all
P |
| doi_str_mv | 10.1152/jappl.1997.83.1.160 |
| format | Article |
| fullrecord | <record><control><sourceid>proquest_highw</sourceid><recordid>TN_cdi_highwire_physiology_jap_83_1_160</recordid><sourceformat>XML</sourceformat><sourcesystem>PC</sourcesystem><sourcerecordid>79135190</sourcerecordid><originalsourceid>FETCH-LOGICAL-c471t-95f540f5f1135f5da4f25c739de5002d06cd582f9e8d0ac61c8b160597594ad53</originalsourceid><addsrcrecordid>eNp1UEtv1DAQthCoLIVfgJB8QPSU1E7iOOZWVS0gVeqlnK1Ze5J15TywE7r59_W2S-HCaUb6XjMfIR85yzkXxfk9TJPPuVIyb8qc57xmr8gmIUWWVv6abBopWCZFI9-SdzHeM8arSvATcqIKXiuhNqS_6DAL6GFGSy0a7waM1A20h73rwVPAMG6doQYmMG5eD1jAbvEQ_Epxj8G46IaO_o45jWhxmCGs9GHscfhKgfY4QwYD-DW6-J68acFH_HCcp-Tn9dXd5ffs5vbbj8uLm8xUks-ZEq2oWCtazsu0WqjaQhhZKouCscKy2ljRFK3CxjIwNTfNNn0slBSqAivKU_Ll2XcK468F46x7Fw16DwOOS9RSJWOuWCKWz0QTxhgDtnoK6e2was70oWT9VLI-lKybUnOdcpLq09F-2fZoXzTHVhP--YhDNODbAEMq6YVWSMnr6p_wnet2Dy6gnnappdGP3aqvF-_vcD8fDvgTrCfbJtXZ_1WJ_PfMR2LMp-Y</addsrcrecordid><sourcetype>Aggregation Database</sourcetype><iscdi>true</iscdi><recordtype>article</recordtype><pqid>79135190</pqid></control><display><type>article</type><title>Age-related declines in maximal aerobic capacity in regularly exercising vs. sedentary women: a meta-analysis</title><source>MEDLINE</source><source>American Physiological Society</source><source>Elektronische Zeitschriftenbibliothek - Frei zugängliche E-Journals</source><source>Alma/SFX Local Collection</source><creator>Fitzgerald, Margaret D ; Tanaka, Hirofumi ; Tran, Zung V ; Seals, Douglas R</creator><creatorcontrib>Fitzgerald, Margaret D ; Tanaka, Hirofumi ; Tran, Zung V ; Seals, Douglas R</creatorcontrib><description>Margaret D.
Fitzgerald 1 ,
Hirofumi
Tanaka 1 ,
Zung V.
Tran 2 , and
Douglas R.
Seals 1 , 3
1 Human Cardiovascular Research
Laboratory, Center for Physical Activity, Disease Prevention, and
Aging, Department of Kinesiology, University of Colorado, Boulder
80309; 2 Center for Research
in Ambulatory Health Care Administration, Medical Group Management
Association, Englewood 80112; and
3 Divisions of Cardiology and
Geriatric Medicine, Department of Medicine, University of Colorado
Health Sciences Center, Denver, Colorado 80262
Received 16 September 1996; accepted in final form 12 March 1997.
Fitzgerald, Margaret D., Hirofumi Tanaka, Zung V. Tran, and
Douglas R. Seals. Age-related declines in maximal aerobic capacity
in regularly exercising vs. sedentary women: a meta-analysis. J. Appl. Physiol. 83(1): 160-165, 1997. Our purpose was to determine the relationship between habitual
aerobic exercise status and the rate of decline in maximal aerobic
capacity across the adult age range in women. A meta-analytic approach
was used in which mean maximal oxygen consumption
( O 2 max ) values from
female subject groups (ages 18-89 yr) were obtained from the
published literature. A total of 239 subject groups from 109 studies
involving 4,884 subjects met the inclusion criteria and were
arbitrarily separated into sedentary (groups = 107; subjects = 2,256),
active (groups = 69; subjects = 1,717), and endurance-trained (groups = 63; subjects = 911) populations.
O 2 max averaged 29.7 ± 7.8, 38.7 ± 9.2, and 52.0 ± 10.5 ml · kg 1 · min 1 ,
respectively, and was inversely related to age within each population ( r = 0.82 to 0.87, all
P < 0.0001). The rate of decline in
O 2 max with
increasing subject group age was lowest in sedentary women ( 3.5
ml · kg 1 · min 1
· decade 1 ), greater in
active women ( 4.4
ml · kg 1 · min 1
· decade 1 ), and
greatest in endurance-trained women ( 6.2
ml · kg 1 · min 1 · decade 1 )
(all P < 0.001 vs. each other). When
expressed as percent decrease from mean levels at age ~25 yr, the
rates of decline in
O 2 max were similar
in the three populations ( 10.0 to 10.9%/decade). There
was no obvious relationship between aerobic exercise status and the
rate of decline in maximal heart rate with age. The results of this
cross-sectional study support the hypothesis that, in contrast to the
prevailing view, the rate of decline in maximal aerobic capacity with
age is greater, not smaller, in endurance-trained vs. sedentary women.
The greater rate of decline in
O 2 max in endurance-trained populations may be related to their higher values as
young adults (baseline effect) and/or to greater age-related reductions in exercise volume; however, it does not appear to be
related to a greater rate of decline in maximal heart rate with age.
aging; exercise; maximal oxygen consumption
0161-7567/97 $5.00
Copyright © 1997 the American Physiological Society</description><identifier>ISSN: 8750-7587</identifier><identifier>EISSN: 1522-1601</identifier><identifier>DOI: 10.1152/jappl.1997.83.1.160</identifier><identifier>PMID: 9216959</identifier><identifier>CODEN: JAPHEV</identifier><language>eng</language><publisher>Bethesda, MD: Am Physiological Soc</publisher><subject>Adolescent ; Adult ; Aged ; Aged, 80 and over ; Aging - physiology ; Biological and medical sciences ; Body Weight - physiology ; Clinical Trials as Topic ; Exercise - physiology ; Female ; Fundamental and applied biological sciences. Psychology ; Heart Rate - physiology ; Humans ; Middle Aged ; Oxygen Consumption - physiology ; Physical Fitness ; Regression Analysis ; Vertebrates: body movement. Posture. Locomotion. Flight. Swimming. Physical exercise. Rest. Sports</subject><ispartof>Journal of applied physiology (1985), 1997-07, Vol.83 (1), p.160-165</ispartof><rights>1997 INIST-CNRS</rights><lds50>peer_reviewed</lds50><woscitedreferencessubscribed>false</woscitedreferencessubscribed><citedby>FETCH-LOGICAL-c471t-95f540f5f1135f5da4f25c739de5002d06cd582f9e8d0ac61c8b160597594ad53</citedby><cites>FETCH-LOGICAL-c471t-95f540f5f1135f5da4f25c739de5002d06cd582f9e8d0ac61c8b160597594ad53</cites></display><links><openurl>$$Topenurl_article</openurl><openurlfulltext>$$Topenurlfull_article</openurlfulltext><thumbnail>$$Tsyndetics_thumb_exl</thumbnail><link.rule.ids>315,781,785,3040,27929,27930</link.rule.ids><backlink>$$Uhttp://pascal-francis.inist.fr/vibad/index.php?action=getRecordDetail&idt=2771640$$DView record in Pascal Francis$$Hfree_for_read</backlink><backlink>$$Uhttps://www.ncbi.nlm.nih.gov/pubmed/9216959$$D View this record in MEDLINE/PubMed$$Hfree_for_read</backlink></links><search><creatorcontrib>Fitzgerald, Margaret D</creatorcontrib><creatorcontrib>Tanaka, Hirofumi</creatorcontrib><creatorcontrib>Tran, Zung V</creatorcontrib><creatorcontrib>Seals, Douglas R</creatorcontrib><title>Age-related declines in maximal aerobic capacity in regularly exercising vs. sedentary women: a meta-analysis</title><title>Journal of applied physiology (1985)</title><addtitle>J Appl Physiol (1985)</addtitle><description>Margaret D.
Fitzgerald 1 ,
Hirofumi
Tanaka 1 ,
Zung V.
Tran 2 , and
Douglas R.
Seals 1 , 3
1 Human Cardiovascular Research
Laboratory, Center for Physical Activity, Disease Prevention, and
Aging, Department of Kinesiology, University of Colorado, Boulder
80309; 2 Center for Research
in Ambulatory Health Care Administration, Medical Group Management
Association, Englewood 80112; and
3 Divisions of Cardiology and
Geriatric Medicine, Department of Medicine, University of Colorado
Health Sciences Center, Denver, Colorado 80262
Received 16 September 1996; accepted in final form 12 March 1997.
Fitzgerald, Margaret D., Hirofumi Tanaka, Zung V. Tran, and
Douglas R. Seals. Age-related declines in maximal aerobic capacity
in regularly exercising vs. sedentary women: a meta-analysis. J. Appl. Physiol. 83(1): 160-165, 1997. Our purpose was to determine the relationship between habitual
aerobic exercise status and the rate of decline in maximal aerobic
capacity across the adult age range in women. A meta-analytic approach
was used in which mean maximal oxygen consumption
( O 2 max ) values from
female subject groups (ages 18-89 yr) were obtained from the
published literature. A total of 239 subject groups from 109 studies
involving 4,884 subjects met the inclusion criteria and were
arbitrarily separated into sedentary (groups = 107; subjects = 2,256),
active (groups = 69; subjects = 1,717), and endurance-trained (groups = 63; subjects = 911) populations.
O 2 max averaged 29.7 ± 7.8, 38.7 ± 9.2, and 52.0 ± 10.5 ml · kg 1 · min 1 ,
respectively, and was inversely related to age within each population ( r = 0.82 to 0.87, all
P < 0.0001). The rate of decline in
O 2 max with
increasing subject group age was lowest in sedentary women ( 3.5
ml · kg 1 · min 1
· decade 1 ), greater in
active women ( 4.4
ml · kg 1 · min 1
· decade 1 ), and
greatest in endurance-trained women ( 6.2
ml · kg 1 · min 1 · decade 1 )
(all P < 0.001 vs. each other). When
expressed as percent decrease from mean levels at age ~25 yr, the
rates of decline in
O 2 max were similar
in the three populations ( 10.0 to 10.9%/decade). There
was no obvious relationship between aerobic exercise status and the
rate of decline in maximal heart rate with age. The results of this
cross-sectional study support the hypothesis that, in contrast to the
prevailing view, the rate of decline in maximal aerobic capacity with
age is greater, not smaller, in endurance-trained vs. sedentary women.
The greater rate of decline in
O 2 max in endurance-trained populations may be related to their higher values as
young adults (baseline effect) and/or to greater age-related reductions in exercise volume; however, it does not appear to be
related to a greater rate of decline in maximal heart rate with age.
aging; exercise; maximal oxygen consumption
0161-7567/97 $5.00
Copyright © 1997 the American Physiological Society</description><subject>Adolescent</subject><subject>Adult</subject><subject>Aged</subject><subject>Aged, 80 and over</subject><subject>Aging - physiology</subject><subject>Biological and medical sciences</subject><subject>Body Weight - physiology</subject><subject>Clinical Trials as Topic</subject><subject>Exercise - physiology</subject><subject>Female</subject><subject>Fundamental and applied biological sciences. Psychology</subject><subject>Heart Rate - physiology</subject><subject>Humans</subject><subject>Middle Aged</subject><subject>Oxygen Consumption - physiology</subject><subject>Physical Fitness</subject><subject>Regression Analysis</subject><subject>Vertebrates: body movement. Posture. Locomotion. Flight. Swimming. Physical exercise. Rest. Sports</subject><issn>8750-7587</issn><issn>1522-1601</issn><fulltext>true</fulltext><rsrctype>article</rsrctype><creationdate>1997</creationdate><recordtype>article</recordtype><sourceid>EIF</sourceid><recordid>eNp1UEtv1DAQthCoLIVfgJB8QPSU1E7iOOZWVS0gVeqlnK1Ze5J15TywE7r59_W2S-HCaUb6XjMfIR85yzkXxfk9TJPPuVIyb8qc57xmr8gmIUWWVv6abBopWCZFI9-SdzHeM8arSvATcqIKXiuhNqS_6DAL6GFGSy0a7waM1A20h73rwVPAMG6doQYmMG5eD1jAbvEQ_Epxj8G46IaO_o45jWhxmCGs9GHscfhKgfY4QwYD-DW6-J68acFH_HCcp-Tn9dXd5ffs5vbbj8uLm8xUks-ZEq2oWCtazsu0WqjaQhhZKouCscKy2ljRFK3CxjIwNTfNNn0slBSqAivKU_Ll2XcK468F46x7Fw16DwOOS9RSJWOuWCKWz0QTxhgDtnoK6e2was70oWT9VLI-lKybUnOdcpLq09F-2fZoXzTHVhP--YhDNODbAEMq6YVWSMnr6p_wnet2Dy6gnnappdGP3aqvF-_vcD8fDvgTrCfbJtXZ_1WJ_PfMR2LMp-Y</recordid><startdate>19970701</startdate><enddate>19970701</enddate><creator>Fitzgerald, Margaret D</creator><creator>Tanaka, Hirofumi</creator><creator>Tran, Zung V</creator><creator>Seals, Douglas R</creator><general>Am Physiological Soc</general><general>American Physiological Society</general><scope>IQODW</scope><scope>CGR</scope><scope>CUY</scope><scope>CVF</scope><scope>ECM</scope><scope>EIF</scope><scope>NPM</scope><scope>AAYXX</scope><scope>CITATION</scope><scope>7X8</scope></search><sort><creationdate>19970701</creationdate><title>Age-related declines in maximal aerobic capacity in regularly exercising vs. sedentary women: a meta-analysis</title><author>Fitzgerald, Margaret D ; Tanaka, Hirofumi ; Tran, Zung V ; Seals, Douglas R</author></sort><facets><frbrtype>5</frbrtype><frbrgroupid>cdi_FETCH-LOGICAL-c471t-95f540f5f1135f5da4f25c739de5002d06cd582f9e8d0ac61c8b160597594ad53</frbrgroupid><rsrctype>articles</rsrctype><prefilter>articles</prefilter><language>eng</language><creationdate>1997</creationdate><topic>Adolescent</topic><topic>Adult</topic><topic>Aged</topic><topic>Aged, 80 and over</topic><topic>Aging - physiology</topic><topic>Biological and medical sciences</topic><topic>Body Weight - physiology</topic><topic>Clinical Trials as Topic</topic><topic>Exercise - physiology</topic><topic>Female</topic><topic>Fundamental and applied biological sciences. Psychology</topic><topic>Heart Rate - physiology</topic><topic>Humans</topic><topic>Middle Aged</topic><topic>Oxygen Consumption - physiology</topic><topic>Physical Fitness</topic><topic>Regression Analysis</topic><topic>Vertebrates: body movement. Posture. Locomotion. Flight. Swimming. Physical exercise. Rest. Sports</topic><toplevel>peer_reviewed</toplevel><toplevel>online_resources</toplevel><creatorcontrib>Fitzgerald, Margaret D</creatorcontrib><creatorcontrib>Tanaka, Hirofumi</creatorcontrib><creatorcontrib>Tran, Zung V</creatorcontrib><creatorcontrib>Seals, Douglas R</creatorcontrib><collection>Pascal-Francis</collection><collection>Medline</collection><collection>MEDLINE</collection><collection>MEDLINE (Ovid)</collection><collection>MEDLINE</collection><collection>MEDLINE</collection><collection>PubMed</collection><collection>CrossRef</collection><collection>MEDLINE - Academic</collection><jtitle>Journal of applied physiology (1985)</jtitle></facets><delivery><delcategory>Remote Search Resource</delcategory><fulltext>fulltext</fulltext></delivery><addata><au>Fitzgerald, Margaret D</au><au>Tanaka, Hirofumi</au><au>Tran, Zung V</au><au>Seals, Douglas R</au><format>journal</format><genre>article</genre><ristype>JOUR</ristype><atitle>Age-related declines in maximal aerobic capacity in regularly exercising vs. sedentary women: a meta-analysis</atitle><jtitle>Journal of applied physiology (1985)</jtitle><addtitle>J Appl Physiol (1985)</addtitle><date>1997-07-01</date><risdate>1997</risdate><volume>83</volume><issue>1</issue><spage>160</spage><epage>165</epage><pages>160-165</pages><issn>8750-7587</issn><eissn>1522-1601</eissn><coden>JAPHEV</coden><abstract>Margaret D.
Fitzgerald 1 ,
Hirofumi
Tanaka 1 ,
Zung V.
Tran 2 , and
Douglas R.
Seals 1 , 3
1 Human Cardiovascular Research
Laboratory, Center for Physical Activity, Disease Prevention, and
Aging, Department of Kinesiology, University of Colorado, Boulder
80309; 2 Center for Research
in Ambulatory Health Care Administration, Medical Group Management
Association, Englewood 80112; and
3 Divisions of Cardiology and
Geriatric Medicine, Department of Medicine, University of Colorado
Health Sciences Center, Denver, Colorado 80262
Received 16 September 1996; accepted in final form 12 March 1997.
Fitzgerald, Margaret D., Hirofumi Tanaka, Zung V. Tran, and
Douglas R. Seals. Age-related declines in maximal aerobic capacity
in regularly exercising vs. sedentary women: a meta-analysis. J. Appl. Physiol. 83(1): 160-165, 1997. Our purpose was to determine the relationship between habitual
aerobic exercise status and the rate of decline in maximal aerobic
capacity across the adult age range in women. A meta-analytic approach
was used in which mean maximal oxygen consumption
( O 2 max ) values from
female subject groups (ages 18-89 yr) were obtained from the
published literature. A total of 239 subject groups from 109 studies
involving 4,884 subjects met the inclusion criteria and were
arbitrarily separated into sedentary (groups = 107; subjects = 2,256),
active (groups = 69; subjects = 1,717), and endurance-trained (groups = 63; subjects = 911) populations.
O 2 max averaged 29.7 ± 7.8, 38.7 ± 9.2, and 52.0 ± 10.5 ml · kg 1 · min 1 ,
respectively, and was inversely related to age within each population ( r = 0.82 to 0.87, all
P < 0.0001). The rate of decline in
O 2 max with
increasing subject group age was lowest in sedentary women ( 3.5
ml · kg 1 · min 1
· decade 1 ), greater in
active women ( 4.4
ml · kg 1 · min 1
· decade 1 ), and
greatest in endurance-trained women ( 6.2
ml · kg 1 · min 1 · decade 1 )
(all P < 0.001 vs. each other). When
expressed as percent decrease from mean levels at age ~25 yr, the
rates of decline in
O 2 max were similar
in the three populations ( 10.0 to 10.9%/decade). There
was no obvious relationship between aerobic exercise status and the
rate of decline in maximal heart rate with age. The results of this
cross-sectional study support the hypothesis that, in contrast to the
prevailing view, the rate of decline in maximal aerobic capacity with
age is greater, not smaller, in endurance-trained vs. sedentary women.
The greater rate of decline in
O 2 max in endurance-trained populations may be related to their higher values as
young adults (baseline effect) and/or to greater age-related reductions in exercise volume; however, it does not appear to be
related to a greater rate of decline in maximal heart rate with age.
aging; exercise; maximal oxygen consumption
0161-7567/97 $5.00
Copyright © 1997 the American Physiological Society</abstract><cop>Bethesda, MD</cop><pub>Am Physiological Soc</pub><pmid>9216959</pmid><doi>10.1152/jappl.1997.83.1.160</doi><tpages>6</tpages></addata></record> |
| fulltext | fulltext |
| identifier | ISSN: 8750-7587 |
| ispartof | Journal of applied physiology (1985), 1997-07, Vol.83 (1), p.160-165 |
| issn | 8750-7587 1522-1601 |
| language | eng |
| recordid | cdi_highwire_physiology_jap_83_1_160 |
| source | MEDLINE; American Physiological Society; Elektronische Zeitschriftenbibliothek - Frei zugängliche E-Journals; Alma/SFX Local Collection |
| subjects | Adolescent Adult Aged Aged, 80 and over Aging - physiology Biological and medical sciences Body Weight - physiology Clinical Trials as Topic Exercise - physiology Female Fundamental and applied biological sciences. Psychology Heart Rate - physiology Humans Middle Aged Oxygen Consumption - physiology Physical Fitness Regression Analysis Vertebrates: body movement. Posture. Locomotion. Flight. Swimming. Physical exercise. Rest. Sports |
| title | Age-related declines in maximal aerobic capacity in regularly exercising vs. sedentary women: a meta-analysis |
| url | https://sfx.bib-bvb.de/sfx_tum?ctx_ver=Z39.88-2004&ctx_enc=info:ofi/enc:UTF-8&ctx_tim=2024-12-15T08%3A19%3A36IST&url_ver=Z39.88-2004&url_ctx_fmt=infofi/fmt:kev:mtx:ctx&rfr_id=info:sid/primo.exlibrisgroup.com:primo3-Article-proquest_highw&rft_val_fmt=info:ofi/fmt:kev:mtx:journal&rft.genre=article&rft.atitle=Age-related%20declines%20in%20maximal%20aerobic%20capacity%20in%20regularly%20exercising%20vs.%20sedentary%20women:%20a%20meta-analysis&rft.jtitle=Journal%20of%20applied%20physiology%20(1985)&rft.au=Fitzgerald,%20Margaret%20D&rft.date=1997-07-01&rft.volume=83&rft.issue=1&rft.spage=160&rft.epage=165&rft.pages=160-165&rft.issn=8750-7587&rft.eissn=1522-1601&rft.coden=JAPHEV&rft_id=info:doi/10.1152/jappl.1997.83.1.160&rft_dat=%3Cproquest_highw%3E79135190%3C/proquest_highw%3E%3Curl%3E%3C/url%3E&disable_directlink=true&sfx.directlink=off&sfx.report_link=0&rft_id=info:oai/&rft_pqid=79135190&rft_id=info:pmid/9216959&rfr_iscdi=true |