Supervised Strength Training Program Research Articles

ECG CHARACTERISTICS IN SENIORS PARTICIPATING IN A STRUCTURED FITNESS PROGRAM: A PILOT STUDY

PURPOSE: Undergraduate exercise science students can benefit from curriculum which includes authentic, hands-on opportunities for learning. A 12-lead electrocardiograph (ECG) can serve as both as a teaching and screening tool to assess cardiac abnormalities in seniors (over age 65) prior to beginning an exercise program. The purpose of this pilot study was to evaluate the ECG characteristics of older adults prior to participation in a twice-weekly supervised strength training program. METHODS: Thirty seniors (Males = 10; Females = 20; Age =72 ± 7.6yrs) completed cardiovascular screening with resting 12-lead ECG analysis prior to program participation. An exercise physiologist reviewed all ECG results and any identified abnormalities were referred to a cardiologist. Gender, ECG abnormalities, and anthropometrics were compared using a mixed model ANOVA. Chi-square analysis was used to test for differences in the frequency of ECG findings across gender. RESULTS: Thirty seniors (Males = 10; Females = 20; Age =72 ± 7.6yrs) completed cardiovascular screening with resting 12-lead ECG analysis prior to program participation. An exercise physiologist reviewed all ECG results and any identified abnormalities were referred to a cardiologist. Gender, ECG abnormalities, and anthropometrics were compared using a mixed model ANOVA. Chi-square analysis was used to test for differences in the frequency of ECG findings across gender CONCLUSIONS: A pre-exercise ECG can be a useful teaching and screening tool for students who are preparing to supervise older adults in a structured strength training program. ECG results can be used to adjust training variables (type, duration, and intensity) accordingly for each individual senior participant.

A randomized controlled trial of the effect of supervised progressive cross-continuum strength training and protein supplementation in older medical patients: the STAND-Cph trial

BackgroundDuring hospitalization, older adults (+ 65 years) are inactive, which puts them at risk of functional decline and loss of independence. Systematic strength training can prevent loss of functional performance and combining strength training with protein supplementation may enhance the response in muscle mass and strength. However, we lack knowledge about the effect of strength training commenced during hospitalization and continued after discharge in older medical patients. This assessor-blinded, randomized study investigated the effect of a simple, supervised strength training program for the lower extremities, combined with post-training protein supplementation during hospitalization and in the home setting for 4 weeks after discharge, on the effect on change in mobility in older medical patients.MethodsOlder medical patients (≥ 65 years) admitted acutely from their home to the Emergency Department were randomized to either standard care or supervised progressive strength training and an oral protein supplement during hospitalization and at home 3 days/week for 4 weeks after discharge. The primary outcome was between-group difference in change in mobility from baseline to 4 weeks after discharge assessed by the De Morton Mobility Index, which assesses bed mobility, chair mobility, static and dynamic balance, and walking. Secondary outcomes were 24-h mobility, lower extremity strength, gait speed, grip strength and activities of daily living.ResultsEighty-five patients were randomized to an intervention group (N = 43) or a control group (N = 42). In the intervention group, 43% were highly compliant with the intervention. Our intention-to-treat analysis revealed no between-group difference in mobility (mean difference in change from baseline to 4 weeks, − 4.17 (95% CI − 11.09; 2.74; p = 0.24) nor in any of the secondary outcomes. The per-protocol analysis showed that the daily number of steps taken increased significantly more in the intervention group compared to the control group (mean difference in change from baseline to 4 weeks, 1033.4 steps (95% CI 4.1; 2062.7), p = 0.049, adjusted for mobility at baseline and length of stay; 1032.8 steps (95% CI 3.6; 2061.9), p = 0.049, adjusted for mobility at baseline, length of stay, and steps at baseline).ConclusionsSimple supervised strength training for the lower extremities, combined with protein supplementation initiated during hospitalization and continued at home for 4 weeks after discharge was not superior to usual care in the effect on change in mobility at 4 weeks in older medical patients. For the secondary outcome, daily number of steps, high compliance with the intervention resulted in a greater daily number of steps. Less than half of the patients were compliant with the intervention indicating that a simpler intervention might be needed.Trial registrationClinicalTrials.gov, NCT01964482. Registered on 14 October 2013. Trial protocol PubMed ID (PMID), 27039381.

Oxidative Stress Parameters and Its Associations With Arterial Stiffness in Competitive Powerlifting Athletes After 12-Week Supervised Strength Training.

Jürgenson, J, Serg, M, Kampus, P, Kals, J, Zagura, M, Viru, M, Zilmer, K, Zilmer, M, Eha, J, and Unt, E. Oxidative stress parameters and its associations with arterial stiffness in competitive powerlifting athletes after 12-week supervised strength training. J Strength Cond Res 33(7): 1816-1822, 2019-Available studies have not revealed a clear understanding of the impact of intensive strength training on arterial stiffness and oxidative stress (OxS) parameters, which may have a significant impact on further cardiovascular health of an athlete. The purpose of this study was to evaluate the effect of a 12-week supervised strength training program (SSTP) on oxidative stress indices and its relationship with arterial stiffness in powerlifting athletes. A total of 19 men (28 ± 6 years) exercised for 12 weeks (4 days per week with intensity 60-90% assessed from 1 repetition maximum, 90-120 minutes per session). Oxidative stress parameters and arterial stiffness (SphygmoCor 7.1) were measured before and after SSTP. The study results showed that total peroxide concentration increased and total antioxidant capacity decreased significantly after SSTP. There were no significant changes in carotid-femoral pulse wave velocity (cfPWV) or in the augmentation index. Correlation analysis revealed that the magnitude of the increase of cfPWV was significantly related to the increase of OxS. The current study demonstrated that a 12-week SSTP in powerlifting athletes produced significant changes in OxS indices, which were positively related to increased aortic stiffness. This novel finding may have significant implications about the effect of OxS on cardiovascular health after high-intensity strength training. Furthermore, strength and conditioningcoaches may have to consider the long-term exercise-induced changes in OxS on an individual level, where increased OxS leads to impaired arterial stiffness and cardiovascular health.

Safety And Feasibility Of Strength Training In Patients With Duchenne Muscular Dystrophy

Duchenne muscular dystrophy (DMD) is a rapidly progressive and currently incurable neuromuscular disease. Understanding the role of exercise is important for these patients as high-intensity or eccentric actions can be damaging in DMD yet a lack of loading may exacerbate muscle dysfunction. While a few studies show submaximal exercise may be safe and potentially delay the loss of muscle function in DMD, no study has systematically examined the potential of strengthening exercise to improve muscle function or attenuate disease progression. PURPOSE: To examine the safety and feasibility of a pilot, in-home strengthening intervention consisting of knee extensor (KE) and flexor (KF) exercise in DMD. METHODS: Eight ambulatory boys with DMD [9.3 (0.8) yrs, BMI 19.0 (4.6) kg/m2] on corticosteroid therapy were recruited to undergo 12 weeks of isometric exercise training of the bilateral KE and KF. Exercise prescription consisted of 4 sets x 6 reps, 3x/week at a target intensity of 50% maximal volitional contraction (MVC). At baseline (BL), MVC testing and training familiarization were done for one week on site. The exercise equipment (custom built chair, laptop, and load cell) was subsequently shipped allowing for in-home training and supervision via live video conferencing for each session. Safety outcome measures to assess muscle damage included magnetic resonance proton transverse relaxation time (T2) of KE and KF, pain assessment, and creatine kinase levels at BL, 1, 6, and 12wks. Peak strength (KE and KF MVC) and time to ascend/descend 4 steps were also assessed at BL and 12wks. RESULTS: The 7 boys who completed the strength training program had a compliance of 84.9 (9.0)% for the exercise sessions. The safety measures did not indicate signs of muscle damage [non-significant change in mean T2: KE=2.3 (3.6)% and KF= 0.4 (4.6)%]. Peak torque increased by 20.6% for KE (p<0.01) and 14.3% for KF (p<0.05), and the time to ascend (13.5%, p<0.05) and descend (22.7%, p<0.05) steps improved after exercise training. CONCLUSION: This in-home, 12-week supervised strength training program was safe, feasible, and improved strength and function in boys with DMD. Future research is required to optimize the strengthening protocol and further explore its potential efficacy and clinical application.

Supervised progressive cross-continuum strength training compared with usual care in older medical patients: study protocol for a randomized controlled trial (the STAND-Cph trial).

BackgroundHospitalization in older adults is characterized by physical inactivity and a risk of losing function and independence. Systematic strength training can improve muscle strength and functional performance in older adults. Few studies have examined the effect of a program initiated during hospitalization and continued after discharge. We conducted a feasibility study prior to this trial and found a progression model for loaded sit-to-stands feasible in older medical patients. This study aims to determine whether a simple supervised strength training program for the lower extremities (based on the model), combined with post-training protein supplementation initiated during hospitalization and continued at home for 4 weeks, is superior to usual care on change in mobility 4 weeks after discharge in older medical patients.MethodsEighty older medical patients (65 years or older) acutely admitted from their own homes will be included in this randomized, controlled, parallel-group, investigator-blinded, superiority trial. After baseline assessments patients will be randomized to (1) intervention: progressive strength training during hospitalization and after discharge (home-based), or (2) control: usual care. Shortly after discharge, 4 weeks after discharge (primary end point) and 6 months after discharge patients will be assessed in their own homes. The intervention encompasses strength training consisting of two lower extremity exercises (sit-to-stand and heel raise) daily during hospitalization and three times per week for 4 weeks after discharge. Both exercises follow pre-defined models for progression and will be performed for three sets of 8–12 repetitions maximum in each training session. Thereafter, the patient will be asked to consume a protein supplement given orally containing 18 g milk-based protein. The primary outcome will be change in the de Morton Mobility Index score from baseline to 4 weeks after discharge. Secondary outcomes will be 24-h mobility level, isometric knee extension strength, the 30-sec sit-to-stand test, habitual gait speed, hand-grip strength, and Activities of Daily Living.DiscussionWe chose to investigate the effect of a minimal time-consuming treatment approach, i.e. two well-performed strength training exercises combined with protein supplementation, to facilitate implementation in a busy clinical care setting, given a positive trial outcome.Trial registrationClinicalTrials.gov: NCT01964482.

Effects of Aquatic and Dry Land Resistance Training Devices on Body Composition and Physical Capacity in Postmenopausal Women

To determine the effects of a supervised strength training program on body composition and physical capacity of older women using three different devices: weight machines, elastic bands, and aquatic devices that increase drag forces (ADIDF). Four groups were formed: control group, weight machine group (WMG), elastic band group (EBG) and a group that used ADIDF (ADIDFG). Body composition and physical capacity were assessed before and after the intervention period. The ADIDFG showed improvements in fat mass (FM), fat-free mass of the left arm (FFM-LA) and right arm (FFM-RA), knee push-up test (KPT), squat test (ST) and crunch test (CT) (p <0.05). Individuals in the EBG and WMG also improved their FM, fat free mass (FFM), FFM-LA, FFM-RA, KPU, ST and CT. ADIDF training improves body composition and physical capacity of postmenopausal women as does performing land-based training programs.

The Exercising Together project: Design and recruitment for a randomized, controlled trial to determine the benefits of partnered strength training for couples coping with prostate cancer

Prostate cancer can threaten quality of life for the patient and his spouse and the quality of his marital relationship. The purpose of our study is to evaluate the effects of “Exercising Together” – a partnered strength training program for married couples coping with prostate cancer – on the physical and emotional health of prostate cancer survivors (PCS) and their spouses and on marital quality. We are conducting a 6-month randomized controlled trial with two groups: 1) Exercising Together - a progressive, supervised strength training program and 2) a usual care control condition. The primary aims of this exploratory study are to: 1) Determine the effect of partnered strength training on physical and emotional health (muscle strength, physical function, body composition and self-report physical and mental health) in PCS, 2) Determine the effect of partnered strength training on physical and emotional health in spouses and 3) Explore the effect of partnered strength training on marital quality (incongruence, communication, relationship quality, intimacy) of the PCS and spouse. Target accrual has been met in this study with 64 couples enrolled and randomized to exercise (n=32) or usual care (n=32) groups. This study is the first to examine the feasibility of this exercise format in both the chronically ill patient and spouse and explore benefits at the individual and couple level.

Effects of progressive strength training on muscle mass in type 2 diabetes mellitus patients determined by computed tomography

To examine the effect of a 4-month progressive strength training program on muscle and fat mass assessed by computed tomography (CT) in type 2 diabetes mellitus (T2DM) patients, and to assess the relationships of changes in muscle cross-section area (CSA) with glycaemic control. Twenty adults (mean age +/- SE: 56.4 +/- 0.9 a) with T2DM participated in a supervised strength training program for 4 months 3 days/week. Muscle and fat areas of the quadriceps muscle were estimated by CT volumetry before and immediately after the training. Glycaemic (HbA1c) and anthropometric (BMI, skinfolds) measurements were assessed at 0 and 4 months, respectively. After strength training, muscle strength increased significantly in all measured muscle groups. Quadriceps size (CSA of the muscle) was increased by 2.4% (from 7.99 +/- 0.3 cm(3) to 8.18 +/- 0.3 cm(3), p = 0.003) for the right extremity, 3.9% (from 8.1 +/- 0.4 cm(3) to 8.41 +/- 0.5 cm(3), p = 0.04) for the left side. Fat tissue CSA reduced from 0.66 +/- 0.1 cm(3) to 0.56 +/- 0.12 cm(3) for the right leg (15.3% reduction) and from 0.58 +/- 0.12 cm(3) to 0.37 +/- 0.13 cm(3) for the left leg (35.8% reduction), resulting in a mean fat CSA reduction of 24.8%. Fat mass assessed by skin folds was significantly reduced and lean body mass was significantly increased. The change in muscle CSA was not correlated with the changes in HbA1c or muscle strength. Strength training significantly improves both muscle mass and the muscle to fat ratio in T2DM. However, changes in muscle observed with computed tomography were not related to changes observed in HbA1c with training.

Can a rehabilitative strength training program reverse muscle atrophy/weakness associated with androgen ablation therapy in prostate cancer patients?

9642 Background: Men treated with hormone therapy for prostate cancer often experience fatigue, muscle loss,bone loss and weight gain, among other side effects. To determine the effects of a rehabilitative strength training program on muscle mass and functional capacity in prostate cancer patients receiving androgen ablation therapy 20 patients were randomly assigned to exercise or control groups. Methods: Upper and lower extremity strength measurements (predicted 1-RM ) were made using an algorithm that considers resistance and the number of repetitions. Muscle and fat mass were measured using DXA and functional capacity and lower extremity power were determined with a Wingate Cycle ergometer test. The baseline pre-test was completed prior to commencing hormone therapy and the post-test following a 12-week supervised strength training exercise program consisting of three 90-minute sessions per week. Results: Eight patients acted as control (age= 71.6 yrs, ht=177 cm, wt=86.3 kg, BMI=27.6) and 10 completed the exercise trial (age= 65.8 years, ht=178 cm, wt=85.5 kg, BMI=27.0). Strength measurements in controls decreased (mean change=−3%) over the 12-week period. Strength increased significantly (p<0.05) with the chest press (15%), seated row (14%) and hamstring curl (22%) in exercisers and nonsignificant increases were observed in lat pull (12%) and leg press (4%). Mean change in all exercises, E=+11%. Lean mass and fat mass did not change significantly (p>0.05). Peak power (PP) and total work (TW) decreased in controls (PP=−11%; TW=−10%) and increased in exercisers (PP=+7%; TW=+9%) (p<0.05). Conclusions: This pilot data suggests that a 12-week supervised strength training program helps prostate cancer patients maintain or increase muscle strength and functional capacity while undergoing androgen ablation therapy. No significant financial relationships to disclose.

Variants in MCP1 and MCP1R are Associated with Baseline Muscle Size and Strength

Recent research has implicated several chemokines and their receptors in the pathogenesis of many conditions, including muscle damage and repair. Chemokines and chemokine receptors are members of the inflammatory system in skeletal muscle; examining genetic variation in the genes encoding these proteins may help explain inter-individual differences in muscle, fat, and bone phenotypes as well as differences in the response to resistance training. PURPOSE: We set out to determine if genetic variants of 2 inflammatory genes active in muscle (MCP1 and MCP1R) showed associations with muscle size or strength and the response to resistance training. METHODS: 1200 college-aged subjects underwent a 12 wk supervised strength training program for the upper arm muscles. Muscle size (via MRI) and strength measurements (1 RM and isometric) were taken before and after training. The study participants were then genotyped for genetic variants in the chemokine gene MCP1 (rs3760396, rs2857656, rs4586, rs13900) and the chemokine receptor gene MCP1R (rs3918358 and rs1799864). RESULTS: In females, the C allele of the rs2857656 SNP was associated with higher baseline (1-RM and isometric) muscle quality and lower baseline subcutaneous fat volume (p = 0.0179, p = 0.0415, and p = 0.0118, respectively). In males, the C allele was associated with higher baseline strength (1-RM) and baseline torque (p = 0.0050 and p = 0.0044, respectively). For SNP rs4586, the C allele was associated with higher baseline strength (1-RM and isometric, p = 0.0185 and p = 0.0264, respectively) and with higher baseline torque (1-RM and isometric, p= 0.0105 and p = 0.0204, respectively) in males only. In females, the T allele of the rs13900 SNP was associated with higher baseline (1-RM and isometric) muscle quality and lower baseline subcutaneous fat volume (p = 0.0156, p = 0.0282, and p = 0.0270, respectively). In males, the T allele of this SNP was associated with higher baseline strength (1-RM and isometric), torque, and higher cortical bone volume (p= 0.0029, p = 0.0476, p = 0.0023, and p = 0.0478, respectively). CONCLUSIONS: Variants in the MCP1 and MCP1R genes show strong associations with several body composition components, indicating that inflammatory/immune genes in skeletal muscle contribute to the multigenic system that determines overall body composition.

Strength Training in Children and Teens

When Is a Child Ready to Begin Strength Training? Parents frequently ask at what age their children can start strength training. It should be noted that our nation has health objectives (1) that strive to increase the number of children aged six years and older who regularly participate in physical activities that enhance and maintain muscular fitness. Children can increase strength as part of normal household and yard chores, games, playing at the park, and climbing ropes and jungle gyms. There is no predefined age at which children can begin to participate in a well-organized and supervised strength training program (2, 3). At a minimum, all participants should be able to accept and follow directions (2–6). Generally, if a child or adolescent is capable of participating in an organized youth sport, he or she is capable of participating in an individualized conditioning program designed to condition the body to meet the physical demands imposed by the sport (3–5, 7). A child or adolescent should begin strength training only if he or she believes it to be worthwhile and should be encouraged to continue participation only if the program is fun, challenging, and safe (8). Because many parents are uninformed about the risks, benefits, and expectations of participating in a youth strength training program, the health/fitness professional can help parents to make informed decisions as to the readiness of their children. Some organizations (2, 6–8) suggest that all participants should have a medical examination by a physician knowledgeable in sports medicine before participating in strength training. For apparently healthy children and adolescents, a preparticipation medical exam is desirable but not mandatory (3, 4). A preparticipation physical exam should be required of participants with known or suspected conditions that require treatment or may exclude or limit their participation (3).

Strength training for prepubescent males: is it safe?

This study examined the safety of one type of strength training for prepubescent males. Eighteen males (average age, 8.3 +/- 1.2 years) participated in a 45 min/session, three session/week, 14 week supervised strength training program with an attendance rate of 91.5%. Concentric work was done almost exclusively. KinCom analysis showed significant strength gain in this group (P less than 0.05), while an age, sex, and activity matched control group did not gain strength. Safety was evaluated by injury surveillance, blood pressure and heart rate monitoring, scintigraphy, and creatine phosphokinase measurement. Effects on growth and development, flexibility, and motor performance were also investigated, as these are factors with an impact on sports injury occurrence. Results showed that in the short term, supervised concentric strength training results in a low injury rate and does not adversely affect bone, muscle, or epiphyses; nor does it adversely affect growth, development, flexibility, or motor performance. As the safety question is multifaceted, this should not lead to the conclusion that strength training for prepubescents is uniformly safe. Further research is needed.

The effects of hydraulic resistance strength training in pre-pubertal males

In order to examine the effectiveness and safety of hydraulic resistance strength training in young males, 26 pre-pubertal males (mean age = 8.2 +/- 1.3 yr) completed a 14-wk strength training study. Subjects were evaluated before and after the 14-wk experimental period for pubertal state (Tanner's sexual maturity rating, serum testosterone, and serum dihydroepiandrosterone sulfate). Effectiveness of the strength training program was determined by measuring pre-post differences in: isokinetic strength for flexion and extension at the knee and elbow joints at two speeds (30 degrees and 90 degrees X s-1) (KIN COM, Chattecx, Inc., Chattanooga, TN), flexibility, standing long jump, vertical jump, body composition parameters, maximal oxygen consumption, and creatinine phosphokinase. Safety of strength training was assessed by biphasic musculoskeletal scintigraphy before and after the program and by physician evaluation of complaints by subjects. Strength training subjects (N = 16) participated in a 45 min/session, 3 session/wk, 14-wk supervised strength training program with an attendance rate of 91.5%. Participants performed concentric work using hydraulic resistance equipment (Hydra-Fitness Industries, Belton, TX). Eccentric work was not performed. Control subjects (N = 10) did not strength train but did participate in sport activities and activities of daily living. Results indicated that strength training subjects increased isokinetic strength as a result of strength training (average concentric work/repetition increases by 18.5 to 36.6% for the eight motions tested; torque scores over the first 90% of the range of motion increases by 13.1 to 45.1% for the eight motions tested). These changes were significantly greater than changes seen in the control group (P less than 0.05). Strength training subjects also demonstrated significant improvements (as compared to control subjects) in vertical jump (+10.4%), flexibility (+8.4%), and maximal oxygen consumption [+19.4% (l X min-1), +13.8% (ml X kg X min-1)] after the experimental period. Musculoskeletal scintigraphy revealed no evidence of damage to epiphyses, bone, or muscle as a result of strength training. Only one strength training-related injury was reported (left shoulder pain, 3 strength training sessions missed). In contrast, six strength training subjects sustained injuries during activities of daily living, resulting in 47 missed strength training sessions. It was concluded that, in the short term, supervised concentric strength training using hydraulic resistance equipment is safe and effective in pre-pubertal boys.