Muscles
Conditions
Keywords
Delayed Onset Muscle Soreness, Eccentric exercise, Masters athlete
Brief summary
The purpose of this study to determine if older adults who are healthy and physically active (i.e., Masters athletes) demonstrate slower rates of recovery from unaccustomed strenuous exercise of downhill running than younger peers.
Detailed description
There is a well-conceived notion that the recovery from strenuous exercise gets slower as individuals get older in age. Studies using animal models have demonstrated that stretching of electrically-activated skeletal muscle to mimic eccentric muscle contractions results in a greater decline and slower recovery in muscular force in old mice than in young mice. Similarly, in human studies using sedentary adults, age has been associated with a slower rate of recovery from a series of eccentric contractions. However, the process of aging is often confounded by coexisting diseases and gradual sedentary lifestyles that progress with advancing aging. Could older adults who are apparently healthy and habitually exercising demonstrate slower rates of recovery from strenuous exercise? In a small-scale study, recreationally-active middle-aged adults did not display a slower recovery from unaccustomed eccentric exercise than young adults. Masters athletes are an effective experimental model to address this question as extrinsic factors (e.g., deconditioning, chronic degenerative diseases) that often confound the intrinsic aging process can be minimized in this population. As no study has been conducted in Masters athletes, it is unknown if Masters athletes would experience slower rates of recovery similar to their sedentary peers. With this information as background, the general aim of the proposed study is to determine if older adults who are healthy and physically active demonstrate slower rates of recovery from unaccustomed strenuous exercise of downhill running than younger peers. In an attempt to properly determine the influence of aging and regular physical activity, 4 groups of apparently healthy adults, including young sedentary, young trained, older sedentary, and older trained adults, will be studied. A total of 60 apparently healthy men and women will serve as subjects. Half will be young \[18-40-year-old (n=30)\] and the other half older \[50-80-year-old (n=30)\]. After the screening and familiarization, investigators will ask participants to visit the laboratory four times (four consecutive days) to perform downhill running and to test physiological measurements (muscular strength, pain scale, range of motion, arterial stiffness and blood pressure and blood creatinine and myoglobin concentrations).
Interventions
acute downhill running
Sponsors
Study design
Eligibility
Inclusion criteria
* Sedentary (exercise \< 1 time/week) or well-trained individuals (exercise ≧ 2 times/week) * Ages 18-39 and 50-80 years * Individuals who can safely exercise
Exclusion criteria
* Individuals who reports Symptoms or Signs Suggestive of Disease on the Health Research Questionnaire (heart and respiratory problems, dizziness and ankle edema). * Individuals who report substance abuse within the last 6 months (elicit drugs, alcohol) * Smokers
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Rate of Force Development | After the downhill running protocol, various markers of muscle damage and muscular strength were obtained 24 hours post (the third visit), 48 hours post (the forth visit) and 72 hours post (the fifth visit). | Rate of force development are measured by determining peak torque achieved on an isometric leg extension machine. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Pain Scale | After the downhill running protocol, muscle damage pain scale was measured 24 hours post (the third visit), 48 hours post (the forth visit) and 72 hours post (the fifth visit). | Pain scale on quadriceps muscle was assessed using a validated visual pain scale. The scale was on a 10-point scale (0 being absence of soreness, 10 being worst imaginable soreness). |
Countries
United States
Participant flow
Recruitment details
We planned to recruit a total of 60 participants. However, we were not able to recruit older unfit adults so this group was dropped from the study. Additionally, this was a research project conducted by a visiting scholar and his departure approached quickly so the study was closed prematurely with smaller numbers in each group.
Participants by arm
| Arm | Count |
|---|---|
| Young Fit Young (18-39 yrs) people who have endurance training habit | 15 |
| Young Unfit Young (18-39 yrs) people who have sedentary lifestyle | 10 |
| Older Fit Older (50-80 yrs) people who have endurance training habit | 14 |
| Total | 39 |
Baseline characteristics
| Characteristic | Young Fit | Young Unfit | Older Fit | Total |
|---|---|---|---|---|
| Age, Continuous Age | 27 years STANDARD_DEVIATION 2 | 28 years STANDARD_DEVIATION 2 | 58 years STANDARD_DEVIATION 2 | 38 years STANDARD_DEVIATION 2 |
| Ethnicity (NIH/OMB) Hispanic or Latino | 1 Participants | 0 Participants | 1 Participants | 2 Participants |
| Ethnicity (NIH/OMB) Not Hispanic or Latino | 14 Participants | 10 Participants | 13 Participants | 37 Participants |
| Ethnicity (NIH/OMB) Unknown or Not Reported | 0 Participants | 0 Participants | 0 Participants | 0 Participants |
| Sex: Female, Male Female | 5 Participants | 6 Participants | 8 Participants | 19 Participants |
| Sex: Female, Male Male | 10 Participants | 4 Participants | 6 Participants | 20 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk | EG002 affected / at risk | EG003 affected / at risk |
|---|---|---|---|---|
| deaths Total, all-cause mortality | 0 / 15 | 0 / 10 | 0 / 14 | 0 / 0 |
| other Total, other adverse events | 0 / 15 | 0 / 10 | 0 / 14 | 0 / 0 |
| serious Total, serious adverse events | 0 / 15 | 0 / 10 | 0 / 14 | 0 / 0 |
Outcome results
Rate of Force Development
Rate of force development are measured by determining peak torque achieved on an isometric leg extension machine.
Time frame: After the downhill running protocol, various markers of muscle damage and muscular strength were obtained 24 hours post (the third visit), 48 hours post (the forth visit) and 72 hours post (the fifth visit).
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Young Fit | Rate of Force Development | Baseline | 102 Nm | Standard Error 3 |
| Young Fit | Rate of Force Development | 24h post | 97 Nm | Standard Error 3 |
| Young Fit | Rate of Force Development | 48h post | 100 Nm | Standard Error 2 |
| Young Fit | Rate of Force Development | 72h post | 102 Nm | Standard Error 2 |
| Young Unfit | Rate of Force Development | 72h post | 105 Nm | Standard Error 4 |
| Young Unfit | Rate of Force Development | Baseline | 108 Nm | Standard Error 4 |
| Young Unfit | Rate of Force Development | 48h post | 106 Nm | Standard Error 5 |
| Young Unfit | Rate of Force Development | 24h post | 106 Nm | Standard Error 4 |
| Older Fit | Rate of Force Development | 72h post | 103 Nm | Standard Error 2 |
| Older Fit | Rate of Force Development | 24h post | 100 Nm | Standard Error 3 |
| Older Fit | Rate of Force Development | 48h post | 103 Nm | Standard Error 3 |
| Older Fit | Rate of Force Development | Baseline | 100 Nm | Standard Error 2 |
Pain Scale
Pain scale on quadriceps muscle was assessed using a validated visual pain scale. The scale was on a 10-point scale (0 being absence of soreness, 10 being worst imaginable soreness).
Time frame: After the downhill running protocol, muscle damage pain scale was measured 24 hours post (the third visit), 48 hours post (the forth visit) and 72 hours post (the fifth visit).
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Young Fit | Pain Scale | 72h post | 2.7 arbitrary scale unit from 0 to 10 | Standard Error 0.5 |
| Young Fit | Pain Scale | Baseline | 0.2 arbitrary scale unit from 0 to 10 | Standard Error 0.1 |
| Young Fit | Pain Scale | 48h post | 4.2 arbitrary scale unit from 0 to 10 | Standard Error 0.6 |
| Young Fit | Pain Scale | 24h post | 3.7 arbitrary scale unit from 0 to 10 | Standard Error 0.5 |
| Young Unfit | Pain Scale | 48h post | 4.9 arbitrary scale unit from 0 to 10 | Standard Error 0.7 |
| Young Unfit | Pain Scale | 72h post | 3.2 arbitrary scale unit from 0 to 10 | Standard Error 0.8 |
| Young Unfit | Pain Scale | Baseline | 0.1 arbitrary scale unit from 0 to 10 | Standard Error 0.1 |
| Young Unfit | Pain Scale | 24h post | 4.7 arbitrary scale unit from 0 to 10 | Standard Error 0.6 |
| Older Fit | Pain Scale | 72h post | 1.5 arbitrary scale unit from 0 to 10 | Standard Error 0.4 |
| Older Fit | Pain Scale | 24h post | 2.4 arbitrary scale unit from 0 to 10 | Standard Error 0.6 |
| Older Fit | Pain Scale | 48h post | 2.7 arbitrary scale unit from 0 to 10 | Standard Error 0.6 |
| Older Fit | Pain Scale | Baseline | 0.0 arbitrary scale unit from 0 to 10 | Standard Error 0 |