EAL

EE: Physical Activity (2013-2014)

Citation:

Williamson DL, Kirwan JP. A single bout of concentric resistance exercise increases basal metabolic rate 48 hours after exercise in healthy 59- to 77-year-old men. Gerontol A Biol Sci Med Sci. 1997 Nov; 52(6): M352-M355.

Study Design:

Randomized Crossover Trial

Class:

A - Click here for explanation of classification scheme.

Quality Rating:

NEUTRAL: See Quality Criteria Checklist below.

Research Purpose:

To measure BMR under very controlled conditions 48 hour after a single bout of concentric resistance exercise in a group of healthy men.

Definitions

Steady state: Not defined
Concentric phase: Allowing only positive work on the bench press, or with each leg and test supervisors lower the weight to minimize eccentric work.

Inclusion Criteria:

Understand and give written consent
Passed a medical exam (including CBC and urine chemistry, 75gm oral glucose tolerance test), ECG and resistance exercise stress test
Non-medicated
Non-hypertensive
Non-hyperlipidemic
Free of chronic infection or disease
Non-smokers.

Exclusion Criteria:

Refusal to consent
Not meeting inclusion criteria.

Description of Study Protocol:

Slept in facility for three days to familiarize with procedures and diet; pre-screening test determined an individual’s three repetition maximum (3RM) by graded design.

Anthropometric

Height measured? Yes
Weight measured? Yes
Fat-free mass measured? Hydrostatic weighing.

Clinical

Monitored heart rate? Not specified
Body temperature? No
Medications administered? Excluded.

Resting Energy Expenditure

IC type: Plexi-glass hood with Hartmann-Braun analyzer
Equipment of Calibration: Yes
Coefficient of variation using std gases: No
Rest before measure (state length of time rested if available): Sedentary conditions
Measurement length: 15 minutes
Steady state: Not specified
Fasting length: Yes, overnight
Exercise restrictions XX hours prior to test? Yes. Exercise monitored during three-day pre-trial stay and overnight stay prior to BMR measure in General Clinical Research Center
Room temperature: 22°C±1°C
Number of measures within the measurement period: One
Were some measures eliminated? Not specified
Were a set of measurements averaged? One 30-minute continuous measure
Coefficient of variation in subjects measures? No
Training of measurer? Likely
Subject training of measuring process? Yes.

Dietary

Eucaloric diet (60% CHO, 15% protein, 25% fat) to maintain energy balance; devoid of caffeine and alcohol. Total calories provided based on Harris-Benedict equation. Food consisted of normal foods plus Ensure liquid supplemental formula.

Data Collection Summary:

Outcome(s) and Other Measures

Measured REE [(VO₂, L per minute), VCO₂ (L per minute; ml per kg per minute), RQ, ventilation (L per minute)]
Blood sampling, including plasma insulin and metabolites
Independent variables of weight, height, age, BMI fat-free mass and fat mass.

Description of Actual Data Sample:

Subjects: N=12 older healthy males, aged 59 to 77 years (mean 66.5±5.0 SE)
Range: 27 to 34 years.

Statistical Tests

Mean±SE; paired T-test analysis to test for differences in BMR between control (no exercise) and the exercise trial; P<0.01 were significant.

Summary of Results:

Anthropometric

Men (± SE)	Mean
Weight. kg	80.4±8.8
Height, cm	172.3±6.2
BMI, kg/m²	26.2±1.4
Body fat, percent	23.4±4.3

Concentric Exercise Results

Average weight lifted during each knee extension was 18kg±4kg and average of 36kg±7kg was bench pressed.

Indirect Calorimetry Results

The energy expenditure 48 hours after exercise (extrapolated to a 24-hour period) resulted in a 57kcal per 24-hour significant increase (P<0.0002) in expenditure compared to control (1,570kcal±193kcal per 24 hours vs. 1,627kcal±193kcal per 24 hours, respectively); corresponding to a 3% increase in VO₂. No differences between RER.
Group mean baseline VO₂ consumption was 0.225L±0.3L 0₂ per minute and 48-hour post-exercise measure was 0.232L±0.3L 0₂ per minute.

Author Conclusion:

Principal finding of this study was that an acute bout of concentric resistance exercise caused a 3% increase in BMR among a group of healthy 59- to 77-year-old men 48 hours after the exercise bout
The present study was a duration of –90 minutes [Analyst note: Hard to tell if minus sign (-) or approximate (~) sign.] which has been shown to be sufficient to deplete glycogen stores in concentrically exercised muscle; however, with adequate carbohydrate intake (60% of diet), muscle glycogen would have been replenished and normalized within 48 hours after exercise
Based on our observations, it would appear that up to 50% of the increase in metabolic rate attributed to resistance training may be due to the residual effects of the last exercise bout, at least among older healthy men.

Funding Source:

Government:	NIH
University/Hospital:	College of Health and Human Development, Pennsylvania State University

Reviewer Comments:

Strengths

Extensive screening criteria to ensure study subjects free from selection bias
Controlled for kcal content of dietary intake on RMR measurement days
Three-day training at clinical research center to familiarize with test

Generalizability/Weaknesses

Generalizable to non-obese and healthy older adult males
Convenience sampling bias
RMR measurement accuracy did not clearly define steady state or quantify rest after being transported to measure site and did not specify if any time elapsed from resistance exercise before measurement began
Extrapolation of one 30-minute measure to 24-hour period without use of steady state during the measurement introduces caution in application as increase may not entirely reflect a post-exercise increase.

Quality Criteria Checklist: Primary Research
Relevance Questions
	1.	Would implementing the studied intervention or procedure (if found successful) result in improved outcomes for the patients/clients/population group? (Not Applicable for some epidemiological studies)	Yes
	2.	Did the authors study an outcome (dependent variable) or topic that the patients/clients/population group would care about?	Yes
	3.	Is the focus of the intervention or procedure (independent variable) or topic of study a common issue of concern to dieteticspractice?	Yes
	4.	Is the intervention or procedure feasible? (NA for some epidemiological studies)	Yes

Validity Questions
1.	Was the research question clearly stated?		Yes
	1.1.	Was (were) the specific intervention(s) or procedure(s) [independent variable(s)] identified?	N/A
	1.2.	Was (were) the outcome(s) [dependent variable(s)] clearly indicated?	N/A
	1.3.	Were the target population and setting specified?	N/A
2.	Was the selection of study subjects/patients free from bias?		Yes
	2.1.	Were inclusion/exclusion criteria specified (e.g., risk, point in disease progression, diagnostic or prognosis criteria), and with sufficient detail and without omitting criteria critical to the study?	N/A
	2.2.	Were criteria applied equally to all study groups?	N/A
	2.3.	Were health, demographics, and other characteristics of subjects described?	N/A
	2.4.	Were the subjects/patients a representative sample of the relevant population?	N/A
3.	Were study groups comparable?		N/A
	3.1.	Was the method of assigning subjects/patients to groups described and unbiased? (Method of randomization identified if RCT)	N/A
	3.2.	Were distribution of disease status, prognostic factors, and other factors (e.g., demographics) similar across study groups at baseline?	N/A
	3.3.	Were concurrent controls or comparisons used? (Concurrent preferred over historical control or comparison groups.)	N/A
	3.4.	If cohort study or cross-sectional study, were groups comparable on important confounding factors and/or were preexisting differences accounted for by using appropriate adjustments in statistical analysis?	N/A
	3.5.	If case control study, were potential confounding factors comparable for cases and controls? (If case series or trial with subjects serving as own control, this criterion is not applicable.)	N/A
	3.6.	If diagnostic test, was there an independent blind comparison with an appropriate reference standard (e.g., "gold standard")?	N/A
4.	Was method of handling withdrawals described?		Yes
	4.1.	Were follow-up methods described and the same for all groups?	N/A
	4.2.	Was the number, characteristics of withdrawals (i.e., dropouts, lost to follow up, attrition rate) and/or response rate (cross-sectional studies) described for each group? (Follow up goal for a strong study is 80%.)	N/A
	4.3.	Were all enrolled subjects/patients (in the original sample) accounted for?	N/A
	4.4.	Were reasons for withdrawals similar across groups?	N/A
	4.5.	If diagnostic test, was decision to perform reference test not dependent on results of test under study?	N/A
5.	Was blinding used to prevent introduction of bias?		No
	5.1.	In intervention study, were subjects, clinicians/practitioners, and investigators blinded to treatment group, as appropriate?	N/A
	5.2.	Were data collectors blinded for outcomes assessment? (If outcome is measured using an objective test, such as a lab value, this criterion is assumed to be met.)	N/A
	5.3.	In cohort study or cross-sectional study, were measurements of outcomes and risk factors blinded?	N/A
	5.4.	In case control study, was case definition explicit and case ascertainment not influenced by exposure status?	N/A
	5.5.	In diagnostic study, were test results blinded to patient history and other test results?	N/A
6.	Were intervention/therapeutic regimens/exposure factor or procedure and any comparison(s) described in detail? Were interveningfactors described?		Yes
	6.1.	In RCT or other intervention trial, were protocols described for all regimens studied?	N/A
	6.2.	In observational study, were interventions, study settings, and clinicians/provider described?	N/A
	6.3.	Was the intensity and duration of the intervention or exposure factor sufficient to produce a meaningful effect?	N/A
	6.4.	Was the amount of exposure and, if relevant, subject/patient compliance measured?	N/A
	6.5.	Were co-interventions (e.g., ancillary treatments, other therapies) described?	N/A
	6.6.	Were extra or unplanned treatments described?	N/A
	6.7.	Was the information for 6.4, 6.5, and 6.6 assessed the same way for all groups?	N/A
	6.8.	In diagnostic study, were details of test administration and replication sufficient?	N/A
7.	Were outcomes clearly defined and the measurements valid and reliable?		No
	7.1.	Were primary and secondary endpoints described and relevant to the question?	N/A
	7.2.	Were nutrition measures appropriate to question and outcomes of concern?	N/A
	7.3.	Was the period of follow-up long enough for important outcome(s) to occur?	N/A
	7.4.	Were the observations and measurements based on standard, valid, and reliable data collection instruments/tests/procedures?	N/A
	7.5.	Was the measurement of effect at an appropriate level of precision?	N/A
	7.6.	Were other factors accounted for (measured) that could affect outcomes?	N/A
	7.7.	Were the measurements conducted consistently across groups?	N/A
8.	Was the statistical analysis appropriate for the study design and type of outcome indicators?		Yes
	8.1.	Were statistical analyses adequately described and the results reported appropriately?	N/A
	8.2.	Were correct statistical tests used and assumptions of test not violated?	N/A
	8.3.	Were statistics reported with levels of significance and/or confidence intervals?	N/A
	8.4.	Was "intent to treat" analysis of outcomes done (and as appropriate, was there an analysis of outcomes for those maximally exposed or a dose-response analysis)?	N/A
	8.5.	Were adequate adjustments made for effects of confounding factors that might have affected the outcomes (e.g., multivariate analyses)?	N/A
	8.6.	Was clinical significance as well as statistical significance reported?	N/A
	8.7.	If negative findings, was a power calculation reported to address type 2 error?	N/A
9.	Are conclusions supported by results with biases and limitations taken into consideration?		Yes
	9.1.	Is there a discussion of findings?	N/A
	9.2.	Are biases and study limitations identified and discussed?	N/A
10.	Is bias due to study's funding or sponsorship unlikely?		Yes
	10.1.	Were sources of funding and investigators' affiliations described?	N/A
	10.2.	Was the study free from apparent conflict of interest?	N/A