Brett A. Dolezal

Muscle damage and resting metabolic rate after acute resistance exercise with an eccentric overload.

PURPOSE The purpose of this investigation was to determine whether muscle damage caused from acute resistance exercise with an eccentric overload would influence resting metabolic rate (RMR) up to 72 h postexercise in resistance-trained (RT) and untrained (UT) subjects. METHODS Nine RT and 9 UT male subjects (mean +/- SD; age = 20.7 +/- 2.1 yr; body mass = 79.0 +/- 1.4 kg; height = 178.4 +/- 3.1 cm; and body fat = 10.2 +/- 1.6%) were measured for RMR, creatine kinase concentration ([CK]), and rating of perceived muscle soreness (RPMS) on five consecutive mornings. To induce muscle damage, after the measurements on day 2, each subject performed leg presses that emphasized the eccentric movement for 8 sets at his six-repetition maximum (6-RM). RESULTS Compared with baseline, the RMR (kJ x d(-1) and kJ x kg FFM(-1) x h(-1) was significantly elevated for RT and UT at 24 h and 48 h postexercise. From 24 h to 48 h to 72 h postexercise, RMR significantly decreased within both groups. The UT group had a significantly higher RMR at 24 h (9,705.4 +/- 204.5 kJ x d(-1)) and 48 h postexercise (8,930.9 +/- 104.4 kJ x d(-1)) when compared with the RT group (9,209.3 +/- 535.3 and 8,601.7 + 353.7 kJ x d(-1)). Both [CK] and RPMS showed a similar time course. CONCLUSION There was a significantly higher [CK] for the UT group at 24 h postexercise (320.4 +/- 20.1 U x L(-1)) and for both [CK] and RPMS at 48 h (1,140.3 +/- 37.1 U x L(-1) and 4.4 +/- 0.5, respectively) and 72 h postexercise (675.9 +/- 41.7 U x L(-1) and 1.67 +/- 0.5, respectively) when compared with the RT group (24 h, 201.9 +/- 13.4 U x L(-1); 48 h, 845.4 +/- 30.7 U x L(-1) and 3.7 +/- 0.5: and 72 h postexercise, 420.2 +/- 70.2 U x L(-1) and 0.89 +/- 0.3). These data indicate that eccentrically induced muscle damage causes perturbations in RMR up to 48 h postexercise.

Eight weeks of exercise training improves fitness measures in methamphetamine-dependent individuals in residential treatment.

Objectives:Physical exercise has been shown to benefit diverse medical and behavioral conditions. This study assesses the feasibility and efficacy of an 8-week endurance and resistance training program on fitness measures in individuals undergoing residential treatment for methamphetamine (MA) dependence. Methods:A total of 39 MA-dependent individuals were randomized to 3 days/week of exercise training (ET, n = 15) or health education without training (equal attention [EA], n = 14) over 8 weeks. Aerobic performance (O2max) was measured by indirect calorimetry, body composition by skinfolds, muscle strength by 1-repetition maximum (1-RM), and endurance at 85% of 1-RM for both leg press (LP) and chest press (CP). Results:A total of 29 individuals completed the study for a 74% adherence rate. Baseline characteristics (mean ± SD) were balanced between groups: age 31 ± 7 years; height = 1.74 ± 0.07 m; weight 82.0 ± 15.0 kg. The ET group significantly improved O2max by 0.63 ± 0.22 L/min (+21%), LP strength by 24.4 ± 5.6 kg (+40%), and CP strength by 20.6 ± 5.7 kg (+49%). The ET group increased LP and CP endurance by 120% and 96%, respectively and showed significant reductions in body weight of 1.7 ± 2.4 kg (−2%), % body fat of 2.8 ± 1.3% (−15%), and fat weight 2.8 ± 1.8 kg (−18%). All changes were significant (P < 0.001) for ET, and no changes were seen for the EA group. Conclusions:Individuals recovering from MA dependence showed substantial improvements in aerobic exercise performance, muscle strength and endurance, and body composition with ET. These findings demonstrate the feasibility of an ET intervention in these participants and also show excellent responsiveness to the exercise stimulus resulting in physiological changes that might enhance recovery from drug dependency.

Effect of Exercise Training on Striatal Dopamine D2/D3 Receptors in Methamphetamine Users during Behavioral Treatment

Methamphetamine use disorder is associated with striatal dopaminergic deficits that have been linked to poor treatment outcomes, identifying these deficits as an important therapeutic target. Exercise attenuates methamphetamine-induced neurochemical damage in the rat brain, and a preliminary observation suggests that exercise increases striatal D2/D3 receptor availability (measured as nondisplaceable binding potential (BPND)) in patients with Parkinson’s disease. The goal of this study was to evaluate whether adding an exercise training program to an inpatient behavioral intervention for methamphetamine use disorder reverses deficits in striatal D2/D3 receptors. Participants were adult men and women who met DSM-IV criteria for methamphetamine dependence and were enrolled in a residential facility, where they maintained abstinence from illicit drugs of abuse and received behavioral therapy for their addiction. They were randomized to a group that received 1 h supervised exercise training (n=10) or one that received equal-time health education training (n=9), 3 days/week for 8 weeks. They came to an academic research center for positron emission tomography (PET) using [18F]fallypride to determine the effects of the 8-week interventions on striatal D2/D3 receptor BPND. At baseline, striatal D2/D3 BPND did not differ between groups. However, after 8 weeks, participants in the exercise group displayed a significant increase in striatal D2/D3 BPND, whereas those in the education group did not. There were no changes in D2/D3 BPND in extrastriatal regions in either group. These findings suggest that structured exercise training can ameliorate striatal D2/D3 receptor deficits in methamphetamine users, and warrants further evaluation as an adjunctive treatment for stimulant dependence.

Exercise Training Improves Heart Rate Variability after Methamphetamine Dependency

PURPOSE Heart rate variability (HRV) reflects a healthy autonomic nervous system and is increased with physical training. Methamphetamine dependence (MD) causes autonomic dysfunction and diminished HRV. We compared recently abstinent methamphetamine-dependent participants with age-matched, drug-free controls (DF) and also investigated whether HRV can be improved with exercise training in the methamphetamine-dependent participants. METHODS In 50 participants (MD = 28; DF = 22), resting heart rate (HR; R-R intervals) was recorded over 5 min while seated using a monitor affixed to a chest strap. Previously reported time domain (SDNN, RMSSD, pNN50) and frequency domain (LFnu, HFnu, LF/HF) parameters of HRV were calculated with customized software. MD were randomized to thrice-weekly exercise training (ME = 14) or equal attention without training (MC = 14) over 8 wk. Groups were compared using paired and unpaired t-tests. Statistical significance was set at P ≤ 0.05. RESULTS Participant characteristics were matched between groups (mean ± SD): age = 33 ± 6 yr; body mass = 82.7 ± 12 kg, body mass index = 26.8 ± 4.1 kg·min. Compared with DF, the MD group had significantly higher resting HR (P < 0.05), LFnu, and LF/HF (P < 0.001) as well as lower SDNN, RMSSD, pNN50, and HFnu (all P < 0.001). At randomization, HRV indices were similar between ME and MC groups. However, after training, the ME group significantly (all P < 0.001) increased SDNN (+14.7 ± 2.0 ms, +34%), RMSSD (+19.6 ± 4.2 ms, +63%), pNN50 (+22.6% ± 2.7%, +173%), HFnu (+14.2 ± 1.9, +60%), and decreased HR (-5.2 ± 1.1 bpm, -7%), LFnu (-9.6 ± 1.5, -16%), and LF/HF (-0.7 ± 0.3, -19%). These measures did not change from baseline in the MC group. CONCLUSIONS HRV, based on several conventional indices, was diminished in recently abstinent, methamphetamine-dependent individuals. Moreover, physical training yielded a marked increase in HRV, representing increased vagal modulation or improved autonomic balance.

Firefighter health and fitness assessment: a call to action.

Abstract Storer, TW, Dolezal, BA, Abrazado, ML, Smith, DL, Batalin, MA, Tseng, C-H, and Cooper, CB; The PHASER Study Group. Firefighter health and fitness assessment: A call to action. J Strength Cond Res 28(3): 661–671, 2014—Sudden cardiac deaths experienced by firefighters in the line of duty account for the largest proportion of deaths annually. Several fire service standards for fitness and wellness have been recommended but currently only 30% of U.S. fire departments are implementing programs for this purpose. The Department of Homeland Security Science and Technology Directorate has initiated the Physiological Health Assessment System for Emergency Responders (PHASER) program aiming to reduce these line-of-duty deaths through an integration of medical science and sensor technologies. Confirming previous reports, PHASER comprehensive risk assessment has identified lack of physical fitness with propensity for overexertion as a major modifiable risk factor. We sought to determine if current levels of fitness and cardiovascular disease (CVD) risk factors in a contemporary cohort of firefighters were better than those reported over the past 30 years. Fifty-one firefighters from a Southern California department were characterized for physical fitness and CVD risk factors using standard measures. Overall, physical fitness and risk factors were not different from previous reports of firefighter fitness and most subjects did not achieve recommended fitness standards. Considering the lack of widespread implementation of wellness/fitness programs in the U.S. fire service together with our findings that low physical fitness and the presence of CVD risk factors persist, we issue a call to action among health and fitness professionals to assist the fire service in implementing programs for firefighters that improve fitness and reduce CVD risk factors. Fitness professionals should be empowered to work with fire departments lending their expertise to guide programs that achieve these objectives, which may then lead to reduced incidence of sudden cardiac death or stroke.

Impact of an exercise intervention on methamphetamine use outcomes post-residential treatment care.

BACKGROUND We examined the efficacy of an 8-week exercise intervention on posttreatment methamphetamine (MA) use among MA-dependent individuals following residential treatment. METHODS 135 individuals newly enrolled in treatment were randomly assigned to a structured 8-week exercise intervention or health education control group. Approximately 1 week after completion of the intervention, participants were discharged to the community. Interview data and urine samples were collected at 1-, 3-, and 6-months post-residential care. Of the sample, 54.8% were classified as higher severity users (using MA more than 18 days in the month before admission) and 45.2% as lower severity users (using MA for up to 18 days in the month before admission). Group differences in MA use outcomes were examined over the 3 timepoints using mixed-multivariate modeling. RESULTS While fewer exercise participants returned to MA use compared to education participants at 1-, 3- and 6-months post-discharge, differences were not statistically significant. A significant interaction for self-reported MA use and MA urine drug test results by condition and MA severity was found: lower severity users in the exercise group reported using MA significantly fewer days at the three post-discharge timepoints than lower severity users in the education group. Lower severity users in the exercise group also had a lower percentage of positive urine results at the three timepoints than lower severity users in the education group. These relationships were not present in the comparison of the higher severity conditions. CONCLUSION Results support the value of exercise as a treatment component for individuals using MA 18 or fewer days/month.

Exercise for methamphetamine dependence: Rationale, design, and methodology

BACKGROUND Effective pharmacotherapies to treat methamphetamine (MA) dependence have not been identified, and behavioral therapies are marginally effective. Based on behavioral studies demonstrating the potential efficacy of aerobic exercise for improving depressive symptoms, anxiety, cognitive deficits, and substance use outcomes, the study described here is examining exercise as a potential treatment for MA-dependent individuals. METHODS This study is randomizing 150 participants with MA dependence at a residential treatment facility for addictive disorders to receive either a thrice-weekly structured aerobic and resistance exercise intervention or a health education condition. Recruitment commenced in March, 2010. Enrollment and follow-up phases are ongoing, and recruitment is exceeding targeted enrollment rates. CONCLUSIONS Seeking evidence for a possibly effective adjunct to traditional behavioral approaches for treatment of MA dependence, this study is assessing the ability of an 8-week aerobic and resistance exercise protocol to reduce relapse to MA use during a 12-week follow-up period after discharge from residential-based treatment. The study also is evaluating improvements in health and functional outcomes during and after the protocol. This paper describes the design and methods of the study.

The Impact of Exercise On Depression and Anxiety Symptoms Among Abstinent Methamphetamine-Dependent Individuals in A Residential Treatment Setting

BACKGROUND This paper reports data from a study designed to determine the impact of an 8-week exercise program on depression and anxiety symptoms among newly abstinent methamphetamine (MA)-dependent individuals in residential treatment. METHODS One hundred thirty-five MA-dependent individuals, newly enrolled in residential treatment, were randomly assigned to receive either a 3-times-per-week, 60-minute structured exercise program for 8 weeks (24 sessions) or an equivalent number of health education sessions. Using mixed-modeling repeated-measures regression, we examined changes in weekly total depression and anxiety scores as measured by the Beck Depression Inventory and Beck Anxiety Inventory over the 8-week study period. RESULTS Mean age of participants was 31.7 (SD = 6.9); 70.4% were male and 48% Latino. Analyses indicate a significant effect of exercise on reducing depression (β = -0.63, P = 0.001) and anxiety (β = -0.95, P=0.001) symptoms (total scores) over the 8-week period compared to a health education control group. A significant dose interaction effect between session attendance and exercise was found as well on reducing depression (β = -0.61, P < 0.001) and anxiety symptoms (β = -0.22, P=0.009) over time compared to the control group. CONCLUSIONS Results support the role of a structured exercise program as an effective intervention for improving symptoms of depression and anxiety associated with MA abstinence.

Effect of Supervised, Periodized Exercise Training vs. Self-directed Training on Lean Body Mass and Other Fitness Variables in Health Club Members

Abstract Storer, TW, Dolezal, BA, Berenc, MN, Timmins, JE, and Cooper, CB. Effect of supervised, periodized exercise training vs. self-directed training on lean body mass and other fitness variables in health club members. J Strength Cond Res 28(7): 1995–2006, 2014—Conventional wisdom suggests that exercise training with a personal trainer (PTr) is more beneficial for improving health-related fitness than training alone. However, there are no published data that confirm whether fitness club members who exercise with a PTr in the fitness club setting obtain superior results compared with self-directed training. We hypothesized that club members randomized to receive an evidence-based training program would accrue greater improvements in lean body mass (LBM) and other fitness measures than members randomized to self-training. Men, aged 30–44 years, who were members of a single Southern California fitness club were randomized to exercise with a PTr administering a nonlinear periodized training program (TRAINED, N = 17) or to self-directed training (SELF, N = 17); both groups trained 3 days per week for 12 weeks. Lean body mass was determined by dual-energy x-ray absorptiometry. Secondary outcomes included muscle strength 1 repetition maximum (1RM), leg power (vertical jump), and aerobic capacity (V[Combining Dot Above]O2max). TRAINED individuals increased LBM by 1.3 (0.4) kg, mean (SEM) vs. no change in SELF, p = 0.029. Similarly, significantly greater improvements were seen for TRAINED vs. SELF in chest press strength (42 vs. 19%; p = 0.003), peak leg power (6 vs. 0.6%; p < 0.0001), and V[Combining Dot Above]O2max (7 vs. −0.3%; p = 0.01). Leg press strength improved 38 and 25% in TRAINED and SELF, respectively (p = 0.14). We have demonstrated for the first time in a fitness club setting that members whose training is directed by well-qualified PTrs administering evidence-based training regimens achieve significantly greater improvements in LBM and other dimensions of fitness than members who direct their own training.

Evaluation of a Wearable Physiological Status Monitor During Simulated Fire Fighting Activities

A physiological status monitor (PSM) has been embedded in a fire-resistant shirt. The purpose of this research study was to examine the ability of the PSM-shirt to accurately detect heart rate (HR) and respiratory rate (RR) when worn under structural fire fighting personal protective equipment (PPE) during the performance of various activities relevant to fire fighting. Eleven healthy, college-aged men completed three activities (walking, searching/crawling, and ascending/descending stairs) that are routinely performed during fire fighting operations while wearing the PSM-shirt under structural fire fighting PPE. Heart rate and RR recorded by the PSM-shirt were compared to criterion values measured concurrently with an ECG and portable metabolic measurement system, respectively. For all activities combined (overall) and for each activity, small differences were found between the PSM-shirt and ECG (mean difference [95%CI]: overall: −0.4 beats/min [−0.8, −0.1]; treadmill: −0.4 beats/min [−0.7, −0.1]; search: −1.7 beats/min [−3.1, −.04]; stairs: 0.4 beats/min [0.04, 0.7]). Standard error of the estimate was 3.5 beats/min for all tasks combined and 1.9, 5.9, and 1.9 beats/min for the treadmill walk, search, and stair ascent/descent, respectively. Correlations between the PSM-shirt and criterion heart rates were high (r = 0.95 to r = 0.99). The mean difference between RR recorded by the PSM-shirt and criterion overall was 1.1 breaths/min (95%CI: −1.9 to −0.4). The standard error of the estimate for RR ranged from 4.2 breaths/min (treadmill) to 8.2 breaths/min (search), with an overall value of 6.2 breaths/min. These findings suggest that the PSM-shirt provides valid measures of HR and useful approximations of RR when worn during fire fighting duties.