Exercise, Health & You: How Much Is Enough?

A place to get your questions answered from McDougall staff dietitian, Jeff Novick, MS, RDN.

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Re: Exercise, Health & You: How Much Is Enough?

Postby JeffN » Wed Jul 11, 2018 11:01 am

Is objectively measured light-intensity physical activity associated with health outcomes after adjustment for moderate-to-vigorous physical activity in adults? A systematic review.
Int J Behav Nutr Phys Act. 2018 Jul 9;15(1):65. doi: 10.1186/s12966-018-0695-z.

https://ijbnpa.biomedcentral.com/articl ... 018-0695-z

Abstract

BACKGROUND:
An increasing number of studies have demonstrated that light-intensity physical activity (LPA) confers health benefits after adjustment for moderate-to-vigorous physical activity (MVPA). The purpose of this systematic review was to summarize existing epidemiological evidence on associations of objectively measured LPA with health outcomes in adults.

METHODS:
This review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched on PubMed, Web of Science, CINAL, and Cochrane Library for articles analyzing the association between objectively determined LPA and health outcomes that were published up to January 2017. Data were extracted regarding authors, publication year, country of survey, study setting, number of participants, study design, physical activity (PA) assessment (type of accelerometer and intensity), health outcomes, confounders, and results (summary measures and association). A coding system was used to summarize the results.

RESULTS:
Of the 3254 studies identified, 24 cross-sectional and 6 longitudinal studies were included in this review. Most of the studies targeted the Western population. LPA was inversely associated with all-cause mortality risk and associated favorably with some cardiometabolic risk factors including waist circumference, triglyceride levels, insulin, and presence of metabolic syndrome. Only a small amount of data were available on mental health and cognitive function.

CONCLUSIONS:
LPA appears to be beneficially associated with important health outcomes after adjustment for MVPA in the adult population. Although current global PA guidelines recommend only MVPA, promoting LPA may confer additional health benefits.
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Re: Exercise, Health & You: How Much Is Enough?

Postby JeffN » Mon Oct 01, 2018 6:51 am

The ‘nail in the coffin’

Science of Medicine Feature Review
The Goldilocks Zone for Exercise: Not Too Little, Not Too Much
by James H. O’Keefe, MD, Evan L. O’Keefe, MS & Carl J. Lavie, MD
Missouri Medicine | March/april 2018 | 115:2 | 103
http://www.omagdigital.com/publication/?i=490187

Abstract
Homo sapiens are evolutionarily adapted to be very physically active throughout life, and thus habitual physical activity (PA) is essential for well-being and longevity. Never the less, middle-aged and older individuals engaging in excessive strenuous endurance exercise appear to be at increased risk for a variety of adverse cardiovascular (CV) effects including atrial fibrillation, myocardial fibrosis, and coronary atherosclerosis. An emerging body of evidence indicates U-shaped or reverse J-shaped curves whereby low doses and moderate doses of PA significantly reduce long-term risks for both total mortality and CV mortality, however, at very high doses of chronic strenuous exercise much of the protection against early mortality and CV disease is lost. The optimal dose, or what we term ‘Goldilocks Zone,’ of PA may be: at least 150 minutes per week of moderate-intensity aerobic exercise or 75 minutes per week of vigorous-intensity aerobic activity, but not more than four to five cumulative hours per week of vigorous (heart-pounding, sweat- producing) exercise, especially for those over 45 years of age. It is also important to take at least one day per week off from vigorous exercise. There appears to be no concerns about an upper threshold for safety for leisure-time low-to-moderate intensity activities such as walking at a comfortable pace, housework, gardening, etc. After every 30 consecutive minutes spent sitting, stand up and move, ideally walking briskly for about five minutes.


The Goldilocks Zone for Physical Activity or Physicians Exercise Prescription

• Aim for the CDC Physical Activity Guideline 150 minutes per week of moderate-intensity aerobic exercise or 75 minutes per week of vigorous-intensity aerobic activity

• Try to limit doses of vigorous (heart-pounding, sweat-producing) exercise to not more than 4 to 5 cumulative hours per week, especially for those over 45 years of age.

• After 30 consecutive minutes spent sitting, stand up and move, ideally walking briskly for about 5 minutes. consider a standing desk to reduce prolonged sitting. (NOTE: I call this Intermittent Walking and you can read about it here. viewtopic.php?f=22&t=44648 and here viewtopic.php?f=22&t=57651)

• changing from a completely sedentary lifestyle to one that incorporates even a modest amount of PA will confer substantial benefits to mental and physical health.

• for individuals performing doses of strenuous exercise above recommended levels, consider substituting less aerobically demanding PA, such as walking, yoga, stability exercises, strength training, etc.

• there appears to be no concerns about an upper threshold for safety when performing leisure-time low-to-moderate intensity activities, such as walking at a comfortable pace, housework, gardening, baseball or softball, bowling, volleyball, golf, doubles tennis (and other racquet sports), dancing, croquet, etc.

• Take at least 1 day per week off from vigorous exercise.

• for very high exercisers over 50 years of age, consideration should be given to some cardiac testing (e.g. CT scanning for CAC, or exercise testing and /or echocardiography.)
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Re: Exercise, Health & You: How Much Is Enough?

Postby JeffN » Fri Nov 16, 2018 1:31 pm

Editorial
Marathon Running: An Unhealthy Addiction!
by John C. Hagan, III, MD
Missouri Medicine | March/April 2018 | 115:2 | 97
https://www.msma.org/uploads/6/2/5/3/62 ... _momed.pdf

Marathons, in the Long Run, Not Heart Healthy! This was our call-out cover message in the notable March/April 2014 issue of Missouri Medicine.1 With the passage of time - four years to be exact - it’s now apparent Missouri Medicine authors got it right. Their naysayers got it wrong. The research paper by Robert S. Schwartz, MD, et al., an editorial review by eminent cardiologists Carl J. Lavie, MD, and Peter A. McCullough, MD, and the editorial outlining my ‘heart of stone’ from over three decades of marathon running
remain our most widely publicized original research. They were noted and quoted in the Wall Street Journal, New York Times, and Runner’s World to modestly name only a few.

In this current 2018 editorial and in the following scientific article, “The Goldilocks Zone for Exercise: Not Too Little. Not Too Much,” by James H. O’Keefe, MD, Evan L. O’Keefe, MS, and Carl J. Lavie, MD, (see page 98) Missouri Medicine updates subsequent research that has vindicated our earlier conclusions and assertions. New message: Frequent exercise is extremely important to health but in moderate amounts at low to moderate intensity. Long duration-high intensity exercise is not heart healthy. Moderation in intensity and duration is especially important after 40-45 years of age.
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Re: Exercise, Health & You: How Much Is Enough?

Postby JeffN » Mon Dec 03, 2018 7:22 am

The U.S. Department of Health and Human Services. Executive Summary: Physical Activity Guidelines for Americans, 2ndhttps://health.gov/paguidelines/second-edition/pdf/PAG_ExecutiveSummary.pdf


New Physical Activity Guidelines for Americans
The Nutrition Source
Harvard T.H. Chan School of Public Health
11/13/19

https://www.hsph.harvard.edu/nutritions ... americans/

In November 2018, the U.S. Department of Health and Human Services released its second edition of the Physical Activity Guidelines for Americans to provide evidence-based recommendations for children and adults. [2] Included are new evidence about specific health benefits of exercise and updated guidelines for different age groups: ages 3-5, 6-17, adults, and older adults. Special conditions in adults are addressed such as pregnancy and postpartum, chronic diseases, and disabilities. The guidelines highlight the specific amounts of exercise needed for each age and condition and types of exercises.

- Guidelines for adults are the same but with a new focus: The first edition of the Physical Activity Guidelines for Americans stated that 10-minute bouts of physical activity a few times a day counted toward meeting the guidelines. The second edition removed this requirement to encourage Americans to simply move more frequently throughout the day. The key messages are to move more and sit less, and some activity is better than none. This recommendation is based on new evidence showing a strong relationship between being highly sedentary and an increased risk of heart disease, high blood pressure, and deaths from all causes. All types of physical activity can help offset these risks.

- - For increased health benefits, adults should engage in at least 150 to 300 minutes a week of moderate-intensity aerobic activity, like brisk walking or fast dancing. At least two days a week should include muscle-strengthening activities, such as lifting weights or bodyweight exercises like push-ups, lunges, and squats. Ideally these exercises are spread throughout the week instead of over one or two days; for example, exercising 45 minutes every other day at a moderate to vigorous intensity is more sustainable and safer for your body than exercising for 1 ½ hr on Saturday and Sunday.

- - Exercising for more than 300 minutes a week can improve health even more.

- Guidelines for older adults are the same as adults but should also include balance training such as tai chi or yoga. To ensure safety, before starting a program they should be aware of their level of fitness and any health conditions that may require a modified level of physical activity. Discussing an exercise regimen with their doctor before beginning a program may be helpful. It is important to increase physical activity gradually over time, to “start low and go slow” with lower intensity activities and then gradually increasing how often and how long the activities are performed.
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Re: Exercise, Health & You: How Much Is Enough?

Postby JeffN » Mon Dec 17, 2018 10:25 am

Physical activity less than the recommended amount may prevent the onset of major biological risk factors for cardiovascular disease: a cohort study of 198 919 adults.
Br J Sports Med. 2018 Dec 15. pii: bjsports-2018-099740.
doi: 10.1136/bjsports-2018-099740. [Epub ahead of print]
PMID: 30554146

Abstract
OBJECTIVES:
We examined the dose-response relationship between physical activity (PA) and incidence of cardiovascular disease (CVD) risk factors in adults in Taiwan.
METHODS:
This study included 1 98 919 participants, aged 18-97 years, free of CVD, cancer and diabetes at baseline (1997-2013), who were followed until 2016. At baseline, participants were classified into five PA levels: inactive' (0 metabolic equivalent of task (MET)-h/week), 'lower insufficiently active' (0.1-3.75 MET-h/week), 'upper insufficiently active' (3.75-7.49 MET-h/week), 'active' (7.5-14.99 MET-h/week) and 'highly active' (≥15 MET-h/week]. CVD risk factors were assessed at baseline and at follow-up by physical examination and laboratory tests. Analyses were performed with Cox regression and adjusted for the main confounders.
RESULTS:
During a mean follow-up of 6.0±4.5 years (range 0.5-19 years), 20 447 individuals developed obesity, 19 619 hypertension, 21 592 hypercholesterolaemia, 14 164 atherogenic dyslipidaemia, 24 275 metabolic syndrome and 8548 type 2 diabetes. Compared with inactive participants, those in the upper insufficiently active (but not active) category had a lower risk of obesity (HR 0.92; 95% CI 0.88 to 0.95), atherogenic dyslipidaemia (0.96; 0.90 to 0.99), metabolic syndrome (0.95; 0.92 to 0.99) and type 2 diabetes (0.91; 0.86 to 0.97). Only highly active individuals showed a lower incidence of CVD risk factors than their upper insufficiently active counterparts.
CONCLUSION:
Compared with being inactive, doing half the recommended amount of PA is associated with a lower incidence of several common biological CVD risk factors. Given these benefits, half the recommended amount of PA is an evidence based target for inactive adults.
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Re: Exercise, Health & You: How Much Is Enough?

Postby JeffN » Wed May 29, 2019 2:48 pm

Original Investigation

Association of Step Volume and Intensity With All-Cause Mortality in Older Women
JAMA Intern Med. Published online May 29, 2019. doi:10.1001/jamainternmed.2019.0899

Key Points

Question: Are increased numbers of steps per day associated with lower mortality rates among older women?

Findings: In this cohort study of 16 741 women with a mean age of 72 years, steps per day were measured over 7 days. Women who averaged approximately 4400 steps/d had significantly lower mortality rates during a follow-up of 4.3 years compared with the least active women who took approximately 2700 steps/d; as more steps per day were accrued, mortality rates progressively decreased before leveling at approximately 7500 steps/d.

Meaning: More steps taken per day are associated with lower mortality rates until approximately 7500 steps/d.

Abstract
Importance: A goal of 10 000 steps/d is commonly believed by the public to be necessary for health, but this number has limited scientific basis. Additionally, it is unknown whether greater stepping intensity is associated with health benefits, independent of steps taken per day.

Objective: To examine associations of number of steps per day and stepping intensity with all-cause mortality.

Design, Setting, and Participants: This prospective cohort study included 18 289 US women from the Women’s Health Study who agreed to participate by wearing an accelerometer during waking hours for 7 days between 2011 and 2015. A total of 17 708 women wore and returned their devices; data were downloaded successfully from 17 466 devices. Of these women, 16 741 were compliant wearers (≥10 h/d of wear on ≥4 days) and included in the analyses, which took place between 2018 and 2019.

Exposures: Steps per day and several measures of stepping intensity (ie, peak 1-minute cadence; peak 30-minute cadence; maximum 5-minute cadence; time spent at a stepping rate of ≥40 steps/min, reflecting purposeful steps).

Main Outcomes and Measures: All-cause mortality.

Results: Of the 16 741 women who met inclusion criteria, the mean (SD) age was 72.0 (5.7) years. Mean step count was 5499 per day, with 51.4%, 45.5%, and 3.1% of time spent at 0, 1 to 39 (incidental steps), and 40 steps/min or greater (purposeful steps), respectively. During a mean follow-up of 4.3 years, 504 women died. Median steps per day across low-to-high quartiles of distribution were 2718, 4363, 5905, and 8442, respectively. The corresponding quartile hazard ratios (HRs) associated with mortality and adjusted for potential confounders were 1.00 (reference), 0.59 (95% CI, 0.47-0.75), 0.54 (95% CI, 0.41-0.72), and 0.42 (95% CI, 0.30-0.60), respectively (P < .01). In spline analysis, HRs were observed to decline progressively with higher mean steps per day until approximately 7500 steps/d, after which they leveled. For measures of stepping intensity, higher intensities were associated with significantly lower mortality rates; however, after adjusting for steps per day, all associations were attenuated, and most were no longer significant (highest vs lowest quartile for peak 1-minute cadence, HR = 0.87 [95% CI, 0.68-1.11]; peak 30-minute cadence, HR = 0.86 [95% CI, 0.65-1.13]; maximum 5-minute cadence, HR = 0.80 [95% CI, 0.62-1.05]; and time spent at a stepping rate of ≥40 steps/min, HR = 1.27 [95% CI, 0.96-1.68]; P > .05).

Conclusions and Relevance: Among older women, as few as approximately 4400 steps/d was significantly related to lower mortality rates compared with approximately 2700 steps/d. With more steps per day, mortality rates progressively decreased before leveling at approximately 7500 steps/d. Stepping intensity was not clearly related to lower mortality rates after accounting for total steps per day.
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Re: Exercise, Health & You: How Much Is Enough?

Postby JeffN » Fri Aug 16, 2019 10:18 am

Turns out the same simplicity that applies to nutrition/diet also applies to exercise. Following a complicated variable weight-training routine didn’t make any significant difference compared to a simple unvarying one. Pick a simple compound exercise for each body section and repeat 2-3x a week. I give an example here. Just do it :)

viewtopic.php?f=22&t=57444&p=578249&#p578249

Myofibrillar protein synthesis and muscle hypertrophy individualised responses to systematically changing resistance training variables in trained young men
03 JUL 2019
https://doi.org/10.1152/japplphysiol.00350.2019
https://www.physiology.org/doi/abs/10.1 ... 00350.2019

Abstract

The manipulation of resistance training (RT) variables is used among athletes, recreational exercisers and compromised populations (e.g., elderly) attempting to potentiate muscle hypertrophy. However, it is unknown whether an individual's inherent predisposition dictates the RT-induced muscle hypertrophic response. Twenty resistance-trained young (26(3)y) men performed 8wk unilateral RT (2∙wk-1) with one leg randomly assigned to a standard progressive RT (CON), and the contralateral leg to a variable RT (VAR, modulating exercise load, volume, contraction type and interset rest interval). The VAR leg completed all 4 RT variations every 2wk. Bilateral vastus lateralis cross-sectional area (CSA) was measured pre- and post-RT, and acute integrated myofibrillar protein synthesis (MyoPS) rates were assessed at rest and over 48h following the final RT session. Muscle CSA increase was similar between CON and VAR (P>0.05), despite higher total training volume (TTV) in VAR (P<0.05). The 0-48h integrated MyoPS increase post-exercise was slightly greater for VAR than CON (P<0.05). All participants were considered 'responders' to RT, although none benefited to a greater extent from a specific protocol. Between-subjects variability (MyoPS, 3.30%; CSA, 37.8%) was 40-fold greater than the intra-subject (between legs) variability (MyoPS, 0.08%; CSA, 0.9%). The higher TTV and greater MyoPS response in VAR did not translate to a greater muscle hypertrophic response. Manipulating common RT variables elicited similar muscle hypertrophy than a standard progressive-RT program in trained young men. Intrinsic individual factors are key determinants of the MyoPS and change in muscle CSA compared with extrinsic manipulation of common RT variables.
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Re: Exercise, Health & You: How Much Is Enough?

Postby JeffN » Tue Sep 24, 2019 12:53 pm

Device-measured light-intensity physical activity and mortality: A meta-analysis.
Ku PW, Hamer M, Liao Y, Hsueh MC, Chen LJ.
Scand J Med Sci Sports. 2019 Sep 23. doi: 10.1111/sms.13557. [Epub ahead of print] Review.
PMID: 31545531
Abstract
INTRODUCTION:
The association of light-intensity physical activity (LPA) with mortality is poorly understood. This meta-analysis of cohort studies aimed to examine the dose-response relationships between daily device-measured LPA and mortality in adults aged 18 or older and to explore whether the associations were independent of moderate-to-vigorous physical activity (MVPA).
METHODS:
Searches for prospective cohort studies providing effect estimates of daily LPA (exposure) on all-cause mortality (outcome) were systematically undertaken in electronic databases up to 30 April 2019. Subgroup analyses and meta-regression analyses with random-effects models were performed to quantify the dose-response relationships between daily LPA and mortality. Sensitivity analyses were also conducted to assess the stability of the results.
RESULTS:
A total of 11 studies were included in the meta-analysis. Analyses contained 49,239 individuals (mean age 60.7, SD = 13.6) who were followed up for a mean 6.2 years (2.3 - 14.2 years), during which 3,669 (7.5%) died. In comparison with the reference group (< 3 hours/day), the pooled HRs (and 95% CIs) of mortality were 0.71 (0.62 - 0.82), 0.68 (0.59 - 0.79), 0.56 (0.44 - 0.71) for groups 3 - < 5 hours/day, 5 - < 7 hours/day, and more than 7 hours a day LPA respectively. Meta-regression models indicated that there was a log-cubic dose-response relationship between daily LPA and mortality in adults and older people, independent of MVPA.
CONCLUSIONS:
Time spent in daily LPA was associated with reduced risks of mortality in adults and older people. These data support the inclusion of LPA in the future physical activity guidelines.
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Re: Exercise, Health & You: How Much Is Enough?

Postby JeffN » Sat Dec 28, 2019 9:28 am

A picture is worth a 1000 words and a little exercise goes a long way

This is a classic case of diminishing returns.

A 30 brisk walk is about 3.5 Mets/hour. If done 6x a week, that is 10.5 METs/week. Let’s round off to 10. Going from sedentary to exercising 30 minutes a day would reduce your risk by 31% (From 1.0 to .69). Adding in an additional 30 minutes, from 30 minutes to 60 minutes 6x a week, only gets you another .06 (from .69 to .63). Adding in an additional 30 minutes, from 60 minutes to 90 minutes 6x a week, only gets you another .02 (.63 to .61). Adding in an additional 30 minutes, from 90 minutes to 120 minutes 6x a week, gets you no additional benefit. (.61 to .61)

1st 30 minutes - .31 benefit (31%)
2nd 30 minutes - .06 additional benefit (6%)
3rd 30 minutes - .02 additional benefit (2%)
4th 30 minutes - .00 additional benefit (0%)

Image

Leisure time physical activity and mortality: a detailed pooled analysis of the dose-response relationship. JAMA Intern Med 2015;175:959-67.

Here is an earlier one from earlier in the thread showing the same thing

viewtopic.php?f=22&t=43482#p451282

Image
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Re: Exercise, Health & You: How Much Is Enough?

Postby JeffN » Wed Feb 26, 2020 7:44 am

Official Statement from the AHA

Exercise-Related Acute Cardiovascular Events and Potential Deleterious Adaptations Following Long-Term Exercise Training: Placing the Risks Into Perspective–An Update: A Scientific Statement From the American Heart Association
Originally published26 Feb 2020Circulation. ;0:CIR.0000000000000749

https://www.ahajournals.org/doi/10.1161 ... 0000000749

Abstract
Epidemiological and biological plausibility studies support a cause-and-effect relationship between increased levels of physical activity or cardiorespiratory fitness and reduced coronary heart disease events. These data, plus the well-documented anti-aging effects of exercise, have likely contributed to the escalating numbers of adults who have embraced the notion that “more exercise is better.” As a result, worldwide participation in endurance training, competitive long distance endurance events, and high-intensity interval training has increased markedly since the previous American Heart Association statement on exercise risk. On the other hand, vigorous physical activity, particularly when performed by unfit individuals, can acutely increase the risk of sudden cardiac death and acute myocardial infarction in susceptible people. Recent studies have also shown that large exercise volumes and vigorous intensities are both associated with potential cardiac maladaptations, including accelerated coronary artery calcification, exercise-induced cardiac biomarker release, myocardial fibrosis, and atrial fibrillation. The relationship between these maladaptive responses and physical activity often forms a U- or reverse J-shaped dose-response curve. This scientific statement discusses the cardiovascular and health implications for moderate to vigorous physical activity, as well as high-volume, high-intensity exercise regimens, based on current understanding of the associated risks and benefits. The goal is to provide healthcare professionals with updated information to advise patients on appropriate preparticipation screening and the benefits and risks of physical activity or physical exertion in varied environments and during competitive events.
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Re: Exercise, Health & You: How Much Is Enough?

Postby JeffN » Fri Feb 28, 2020 4:16 pm

Association of Ascending Aortic Dilatation and Long-term Endurance Exercise Among Older Masters-Level Athletes

JAMA Cardiol. Published online February 26, 2020. doi:10.1001/jamacardio.2020.0054

https://jamanetwork.com/journals/jamaca ... erm=022620

Key Points
Question What is the prevalence of aortic dilatation among long-term endurance athletes?

Findings In this cross-sectional study of 442 masters-level athletes, 94 individuals (21%) were found to have an ascending aortic size of 40 mm or larger, representing a marked increase in the prevalence of aortic dilatation compared with that predicted by established age- and sex-specific population nomograms.

Meaning This study identified an elevated prevalence of aortic dilatation among aging endurance athletes without clear explanatory risk factors, suggesting that long-term endurance exercise is associated with aortic enlargement.

Abstract

Importance Aortic dilatation is frequently encountered in clinical practice among aging endurance athletes, but the distribution of aortic sizes in this population is unknown. It is additionally uncertain whether this may represent aortic adaptation to long-term exercise, similar to the well-established process of ventricular remodeling.

Objective To assess the prevalence of aortic dilatation among long-term masters-level male and female athletes with about 2 decades of exercise exposure.

Design, Setting, and Participants This cross-sectional study evaluated aortic size in veteran endurance athletes. Masters-level rowers and runners aged 50 to 75 years were enrolled from competitive athletic events across the United States from February to October 2018. Analysis began January 2019.

Exposures Long-term endurance exercise.

Main Outcomes and Measures The primary outcome was aortic size at the sinuses of Valsalva and the ascending aorta, measured using transthoracic echocardiography in accordance with contemporary guidelines. Aortic dimensions were compared with age, sex, and body size–adjusted predictions from published nomograms, and z scores were calculated where applicable.

Results Among 442 athletes (mean [SD] age, 61 [6] years; 267 men [60%]; 228 rowers [52%]; 214 runners [48%]), clinically relevant aortic dilatation, defined by a diameter at sinuses of Valsalva or ascending aorta of 40 mm or larger, was found in 21% (n = 94) of all participants (83 men [31%] and 11 women [6%]). When compared with published nomograms, the distribution of measured aortic size displayed a rightward shift with a rightward tail (all P < .001). Overall, 105 individuals (24%) had at least 1 z score of 2 or more, indicating an aortic measurement greater than 2 SDs above the population mean. In multivariate models adjusting for age, sex, body size, hypertension, and statin use, both elite competitor status (rowing participation in world championships or Olympics or marathon time under 2 hours and 45 minutes) and sport type (rowing) were independently associated with aortic size.

Conclusions and Relevance Clinically relevant aortic dilatation is common among aging endurance athletes, raising the possibility of vascular remodeling in response to long-term exercise. Longitudinal follow-up is warranted to establish corollary clinical outcomes in this population.



(Study) Conclusions

In conclusion, we present data characterizing ascending aortic dimensions among aging competitive endurance athletes with the principal finding of a marked increase in the prevalence of aortic dilatation based on established population nomograms. This finding was consistent between men and women and across athletes participating in 2 of the most common endurance sports. Thus, it appears that the aorta is an exercise-responsive plastic organ that remodels in the setting of long-term exercise. Further longitudinal study will be required to establish definitive clinical correlates of these findings.
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Re: Exercise, Health & You: How Much Is Enough?

Postby JeffN » Thu Apr 02, 2020 7:18 am

Keep walking! Even if it is around your home!

Association of Daily Step Count and Step Intensity With Mortality Among US Adults
Barry I. Graubard, PhD1; Susan A. Carlson, PhD4; Eric J. Shiroma, ScD5; Janet E. Fulton, PhD4; Charles E. Matthewsh
JAMA. 2020;323(12):1151-1160. doi:10.1001/jama.2020.1382

https://jamanetwork.com/journals/jama/a ... ct/2763292

Question
What are the associations between daily step counts and step intensity with mortality among US adults?

Findings
In this observational study that included 4840 participants, a greater number of steps per day was significantly associated with lower all-cause mortality (adjusted hazard ratio for 8000 steps/d vs 4000 steps/d, 0.49). There was no significant association between step intensity and all-cause mortality after adjusting for the total number of steps per day.

Meaning
Greater numbers of steps per day were associated with lower risk of all-cause mortality.

Abstract
Importance
It is unclear whether the number of steps per day and the intensity of stepping are associated with lower mortality.

Objective
Describe the dose-response relationship between step count and intensity and mortality.

Design, Setting, and Participants
Representative sample of US adults aged at least 40 years in the National Health and Nutrition Examination Survey who wore an accelerometer for up to 7 days ( from 2003-2006). Mortality was ascertained through December 2015.

Exposures
Accelerometer-measured number of steps per day and 3 step intensity measures (extended bout cadence, peak 30-minute cadence, and peak 1-minute cadence [steps/min]). Accelerometer data were based on measurements obtained during a 7-day period at baseline.

Main Outcomes and Measures
The primary outcome was all-cause mortality. Secondary outcomes were cardiovascular disease (CVD) and cancer mortality. Hazard ratios (HRs), mortality rates, and 95% CIs were estimated using cubic splines and quartile classifications adjusting for age; sex; race/ethnicity; education; diet; smoking status; body mass index; self-reported health; mobility limitations; and diagnoses of diabetes, stroke, heart disease, heart failure, cancer, chronic bronchitis, and emphysema.

Results
A total of 4840 participants (mean age, 56.8 years; 2435 [54%] women; 1732 [36%] individuals with obesity) wore accelerometers for a mean of 5.7 days for a mean of 14.4 hours per day. The mean number of steps per day was 9124. There were 1165 deaths over a mean 10.1 years of follow-up, including 406 CVD and 283 cancer deaths. The unadjusted incidence density for all-cause mortality was 76.7 per 1000 person-years (419 deaths) for the 655 individuals who took less than 4000 steps per day; 21.4 per 1000 person-years (488 deaths) for the 1727 individuals who took 4000 to 7999 steps per day; 6.9 per 1000 person-years (176 deaths) for the 1539 individuals who took 8000 to 11 999 steps per day; and 4.8 per 1000 person-years (82 deaths) for the 919 individuals who took at least 12 000 steps per day. Compared with taking 4000 steps per day, taking 8000 steps per day was associated with significantly lower all-cause mortality (HR, 0.49 [95% CI, 0.44-0.55]), as was taking 12 000 steps per day (HR, 0.35 [95% CI, 0.28-0.45]). Unadjusted incidence density for all-cause mortality by peak 30 cadence was 32.9 per 1000 person-years (406 deaths) for the 1080 individuals who took 18.5 to 56.0 steps per minute; 12.6 per 1000 person-years (207 deaths) for the 1153 individuals who took 56.1 to 69.2 steps per minute; 6.8 per 1000 person-years (124 deaths) for the 1074 individuals who took 69.3 to 82.8 steps per minute; and 5.3 per 1000 person-years (108 deaths) for the 1037 individuals who took 82.9 to 149.5 steps per minute. Greater step intensity was not significantly associated with lower mortality after adjustment for total steps per day (eg, highest vs lowest quartile of peak 30 cadence: HR, 0.90 [95% CI, 0.65-1.27]; P value for trend = .34).

Conclusions and Relevance
Based on a representative sample of US adults, a greater number of daily steps was significantly associated with lower all-cause mortality. There was no significant association between step intensity and mortality after adjusting for total steps per day.

Mass Media Article

Stuck Inside? Keep Walking
Taking an extra 4,000 steps a day, even if it’s around your living room, may lower your risk of dying prematurely.
NY Times

https://www.nytimes.com/2020/04/01/well ... ealth.html
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Re: Exercise, Health & You: How Much Is Enough?

Postby JeffN » Mon Aug 31, 2020 12:34 pm

Inflammatory Effects of High and Moderate Intensity Exercise—A Systematic Review
Front Physiol. 2019; 10: 1550.
Published online 2020 Jan 9. doi: 10.3389/fphys.2019.01550

Abstract

Background: Exercise leads to a robust inflammatory response mainly characterized by the mobilization of leukocytes and an increase in circulating inflammatory mediators produced by immune cells and directly from the active muscle tissue. Both positive and negative effects on immune function and susceptibility to minor illness have been observed following different training protocols. While engaging in moderate activity may enhance immune function above sedentary levels, excessive amounts of prolonged, high-intensity exercise may impair immune function. Thus, the aim of the present review was to clarify the inflammatory effects in response to different exercise intensities.

Methods: Search was performed on PubMed and was completed on July 31st, 2017. The studies were eligible if they met the predefined inclusion criteria: a) observational or interventional studies, b) conducted in healthy adults (18–65 years), c) written in Portuguese, English or Spanish, d) including moderate and/or intense exercise. Eighteen articles were included. The specific components that were examined included circulating blood levels of cytokines, leukocytes, creatine kinase (CK) and C-reactive protein (CRP). The methodological quality of the included studies was assessed.

Results: Most of the intervention studies showed changes in the assessed biomarkers, although these changes were not consistent. White blood cells (WBC) had an increase immediately after intensive exercise (> 64% VO2max), without alteration after moderate exercise (46–64% VO2max). The results suggested an elevation of the pro-inflammatory cytokines, namely IL-6, followed by an elevation of IL-10 that were more evident after intense exercise bouts. CRP increased both after intense and moderate exercise, with peak increases up to 28 h. CK increased only after intensive and long exercising.

Conclusion: In summary, intense long exercise can lead, in general, to higher levels of inflammatory mediators, and thus might increase the risk of injury and chronic inflammation. In contrast, moderate exercise or vigorous exercise with appropriate resting periods can achieve maximum benefit.
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Re: Exercise, Health & You: How Much Is Enough?

Postby JeffN » Wed Dec 09, 2020 1:06 pm

Joint associations of accelero-meter measured physical activity and sedentary time with all-cause mortality: a harmonised meta-analysis in more than 44 000 middle-aged and older individuals
British Journal of Sports Medicine 2020;54:1499-1506.

ABSTRACT

Objectives
To examine the joint associations of accelerometer-measured physical activity and sedentary time with all-cause mortality.
Methods We conducted a harmonised meta-analysis including nine prospective cohort studies from four countries. 44 370 men and women were followed for4.0 to 14.5 years during which 3451 participants died (7.8% mortality rate). Associations between different combinations of moderate-to-vigorous intensity physical activity (MVPA) and sedentary time were analysed at study level using Cox proportional hazards regression analysis and summarised using random effects meta- analysis.

Results
Across cohorts, the average time spent sedentary ranged from 8.5 hours/day to 10.5 hours/day and 8 min/day to 35 min/day for MVPA. Compared with the referent group (highest physical activity/lowest sedentary time), the risk of death increased with lower levels of MVPA and greater amounts of sedentary time. Among those in the highest third of MVPA, the risk of death was not statistically different from the referentfor those in the middle (16%; 95% CI 0.87% to 1.54%) and highest (40%; 95% CI 0.87% to 2.26%) thirds of sedentary time. Those in the lowest third of MVPA had a greater risk of death in all combinations with sedentary time; 65% (95% CI 1.25% to 2.19%), 65% (95% CI 1.24% to 2.21%) and 263% (95% CI 1.93% to 3.57%), respectively.

Conclusion
Higher sedentary time is associated with higher mortality in less active individuals when measured by accelerometry. About 30–40 min of MVPA per day attenuate the association between sedentary time and risk of death, which is lower than previous estimates from self-reported data.
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Re: Exercise, Health & You: How Much Is Enough?

Postby JeffN » Thu Sep 16, 2021 8:12 am

U-Shaped Association Between Duration of Sports Activities and Mortality: Copenhagen City Heart Study
Published:August 17, 2021DOI:
https://doi.org/10.1016/j.mayocp.2021.05.028
PlumX Metrics

https://www.mayoclinicproceedings.org/article/S0025-6196(21)00475-4/fulltext

Objective

To investigate the association between the duration of weekly leisure-time sports activity and all-cause mortality.

Methods

As part of the prospective Copenhagen City Heart Study, 8697 healthy adults completed a comprehensive questionnaire about leisure-time sports activities. Duration (minutes per week) of leisure-time sports activities was recorded for tennis, badminton, soccer, handball, cycling, swimming, jogging, calisthenics, health club activities, weightlifting, and other sports. The primary end point was all-cause mortality, and the median follow-up was 25.6 years. The association between duration of leisure-time sports activities and all-cause mortality was studied using multivariable Cox proportional hazards regression analysis.

Results

Compared with the reference group of 2.6 to 4.5 hours of weekly leisure-time sports activities, we found an increased risk for all-cause mortality for those with 0 hours (hazard ratio [HR], 1.51; 95% CI, 1.29 to 1.76), for those with 0.1 to 2.5 hours (HR, 1.24; 95% CI, 1.05 to 1.46), and for those with more than 10 hours (HR, 1.18; 95% CI, 1.00 to 1.39) of weekly leisure-time sports activities. These relationships were generally consistent with additional adjustments for potential confounders among subgroups of age, sex, education, smoking, alcohol intake, and body mass index, when the first 5 years of follow-up were excluded, and for cardiovascular disease mortality.

Conclusion

We observed a U-shaped association between weekly duration of leisure sports activities and cardiovascular and all-cause mortality, with lowest risk for those participating in 2.6 to 4.5 weekly hours, being consistent across subgroups. Participation in sport activities should be promoted, but the potential risk of very high weekly hours of sport participation should be considered for inclusion in guidelines and recommendations.

NOTE: 30 (-45) minutes a day, 5-6 days a week will put you in the range for lowest risk,
30 min x 5 days = 150 minutes /60 = 2.5 hours a week
45 min x 6 days = 270 minutes /60 = 4.5 hours a week
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