High-intensity Resistance Training Program Research Articles

Studying the Impact of High-Intensity Resistance Training on the Physical Fitness of Cricket Players in Government College of Physical Education, Quetta

This study investigated the impact of a 12-week high-intensity resistance training (HIRT) program on cricket players' physical fitness at the Government College of Physical Education in Quetta, Pakistan. The study included twenty male cricket gentleman's (mean age 23.5 years, SD 3.1). Participants were divided into two groups: The group performing the experiment (EG, n = 10) went through the HIRT program, while the control group (CG, n = 10) did not engage in any specific training. Physical fitness assessments were conducted pre- and post-intervention, including tests for muscular strength, power, agility, and endurance. Results showed significant improvements (p < .05) in muscular strength, power, and agility in the EG compared to the CG. However, no significant differences were found in endurance. These results suggest that HIRT can be a successful technique to enhance fitness levels in cricketers.

Application Of Resistance Training And Strength Exercises For Improving Explosive Force In Students Of Sports University Of Tirana

Resistance training is a potent stimulus to the neuromuscular system for muscle hypertrophy and strength gain which is known to have positive effects on health, weight control and performance The capacity for human exercise performance can be enhanced with prolonged exercise training, whether it is endurance or strength-based. The purpose of this study is to analyse the effectiveness of RT performed with strength exercises for improving body composition, muscle strength and explosive force of SUT students. 45 male students of SUT, aged 18-25 years old, had participated in this study. The training period lasted 12 weeks with 3 times per week sessions. The study was performed following a training protocol by control and experimental groups. The paired samples t-test was used to the comparisons within group, whilst the independent samples t-test was used to compare variables between groups at baseline. The main findings of this study is that HIRT procedures improvements in the maximum power output (peak power) and efficiency of the motion at experimental group are slightly greater than those reported at control group and the estimated mean change in maximum power output and efficiency over the training program was 4.08 W/kg and 4.2% efficiency (p < 0.05) when compared the experimental group to control group. In conclusion, the present study suggest that, the high intensity resistance training program composed by functional training, fitness challenge and core & abdominal exercises have the most benefit form improving body composition, peak maximum power, efficiency and explosive force.

Implementation of a rehabilitation model in a Program of All-Inclusive Care for the Elderly (PACE): Preliminary data.

Nursing home eligible participants in the Program of All-inclusive Care for the Elderly (PACE) are at high risk for falls. Physical function is a modifiable predictor of falls and an important target for prevention. We engaged a PACE site to explore feasibility of implementing progressive intensive rehabilitation to improve physical function and preliminary patient-level improvements. The research involved a mixed-methods, pre-post implementation study with longitudinal patient follow-up at one Denver PACE site. Older adults at risk for institutionalization (N=28) took part in Screening and high-intensity interventions to Improve Falls risk and Transform expectations in age and aging (SHIFT) rehabilitation program over six weeks. Outcomes included the short physical performance battery (SPPB); 4-meter gait speed at baseline, discharge, and 6 and 12 months postdischarge from SHIFT. A focus group with staff explored facilitators and barriers to program implementation in the PACE setting and with complex patients and perceived effectiveness. The rehabilitation team demonstrated high treatment fidelity to SHIFT (>80%). No treatment-specific adverse events were reported. SPPB scores and gait speeds improved significantly over time (p < 0.005). The average SPPB score at evaluation was 4.6 ± 0.24 compared to 7.7 ± 0.38 points at discharge. The average gait speed at evaluation was 0.58 ± 0.03 meters/second (m/s) compared to 0.79 ± 0.04 m/s at discharge. Common barriers to program completion included changes in health status and environmental factors (e.g., transportation). Rehabilitation therapists incorporated a high-intensity resistance training program into routine care of complex older adults in PACE and improved pre-post physical function to levels above independence thresholds (SPPB ≥6; gait speed ≥0.65 m/s). Our pilot implementation study informed refinement of eligibility criteria, number of visits, and strategies to address long-term adherence to enhance scalability and optimize impact.

Exercise Interventions for the Prevention and Treatment of Sarcopenia. A Systematic Umbrella Review

The aim of this systematic review is to provide an overview of the efficacy of different exercise interventions to counter sarcopenia in older adults. This review will allow the Belgian Society of Gerontology and Geriatrics and other scientific societies to formulate specific exercise recommendations in their Clinical Guidelines for Sarcopenia. We used the method of a systematic umbrella-review. Based on the level of evidence, we formulated specific recommendations for clinical practice. Two databases (Pubmed and Web Of Science) were searched systematically and methodological quality of the reviews was assessed. Extracted data was than mapped to an exercise category and an overall synthesis (bottom line statements) was formulated for each of these exercise categories. Subsequently, we assigned a rating of the quality of the evidence supporting each bottom line statement. We identified 14 systematic reviews or meta-analyses, encompassing four exercise categories: resistance training, resistance training + nutritional supplementation, multimodal exercise programmes and bloodflow restriction training. Importantly, very few systematic reviews or meta-analyses clearly mentioned baseline sarcopenia status. There is high quality evidence for a positive and significant effect of resistance training on muscle mass, muscle strength, and physical performance. The added effect of nutritional supplementation for resistance training on muscle function appears limited. Blood flow restriction training is a novel training method that has a significant impact on muscle strength. Since sarcopenia is affecting all skeletal muscles in the body, we recommend training the large muscle groups in a total body approach. Although low-intensity resistance training (≤50% 1RM) is sufficient to induce strength gains, we recommend a high-intensity resistance training program (i.e. 80% 1RM) to obtain maximal strength gains. Multimodal exercises and blood flow restriction resistance training may be considered as well.

The Effects Of A High-volume And High-intensity Resistance Training Program On Arterial Stiffness

The Effects Of A High-volume And High-intensity Resistance Training Program On Arterial Stiffness

Resistance training enhances muscular performance in patients with anorexia nervosa: a randomized controlled trial.

Low-intensity exercise applied in anorexia nervosa patients has been shown to have a harmless effect on body composition and to effect short-term improvements in muscular strength and agility. The aim of this study was to determine the effects of a high-intensity resistance training program designed for adolescents to improve strength and agility in anorexia nervosa restricting-type patients (AN-R). From a total of 36 female patients with AN-R, one group (intervention, n = 18) underwent a supervised high-intensity resistance training program lasting 8 weeks, and the other group with no exercise (control, n = 18). Body weight, body mass index, whole-body muscular strength, and agility were assessed before, after, and 4 weeks after training (detraining). Leg-press, bench-press, and lateral row tests improved significantly (p < 0.001) after 8 weeks of training compared with controls. Improvements were maintained after the detraining period. The training program also showed beneficial effects on agility. A high-intensity resistance training program adapted to the recommendations for adolescents in AN-R patients was effective and safe, improving muscular strength in the whole body and the ability to perform daily tasks. However, long-term maintenance of gains seems to be linked to the continuance of training or the use of a maintenance program.

Creatine supplementation post-exercise does not enhance training-induced adaptations in middle to older aged males

Purpose The present study evaluated the effects of creatine monohydrate (CrM) consumption post-exercise on body composition and muscle strength in middle to older males following a 12-week resistance training program.MethodsIn a double-blind, randomized trial, 20 males aged between 55 and 70 years were randomly assigned to consume either CrM-carbohydrate (CHO) [20 g days−1 CrM + 5 g days−1 CHO × 7 days, then 0.1 g kg−1 CrM + 5 g CHO on training days (average dosage of ~8.8 g)] or placebo CHO (20 g days−1 CHO × 7 days, then 5 g CHO on training days) while participating in a high intensity resistance training program [3 sets × 10 repetitions at 75 % of 1 repetition maximum (1RM)], 3 days weeks−1 for 12 weeks. Following the initial 7-day “loading” phase, participants were instructed to ingest their supplement within 60 min post-exercise. Body composition and muscle strength measurements, blood collection and vastus lateralis muscle biopsy were completed at 0, 4, 8 and 12 weeks of the supplement and resistance training program.ResultsA significant time effect was observed for 1RM bench press (p = 0.016), leg press (p = 0.012), body mass (p = 0.03), fat-free mass (p = 0.005) and total myofibrillar protein (p = 0.005). A trend for larger muscle fiber cross-sectional area in the type II fibers compared to type I fibers was observed following the 12-week resistance training (p = 0.08). No supplement interaction effects were observed.ConclusionPost-exercise ingestion of creatine monohydrate does not provide greater enhancement of body composition and muscle strength compared to resistance training alone in middle to older males.

Exertional Rhabdomyolysis in an Acutely Detrained Athlete/Exercise Physiology Professor

The authors report a case of exercise-induced (exertional) rhabdomyolysis in a male athlete/exercise physiology professor who started a high-intensity resistance training program after a period of detraining. The subject performed 1 high-intensity resistance training session that consisted of 48 total sets of push-ups (24) and chin-ups (24) with no rest between the sets. Two days after the exercise session, the subject reported "Cola colored" urine. On arriving at the hospital, test results indicated elevated myoglobin and creatine kinase (CK) levels (59 159 U/L; normal is 20-200 U/L). Treatment included intravenous hydration with sodium bicarbonate to reduce myoglobin, blood work to monitor CK levels, and acupuncture from the shoulder to hand. Three weeks posttreatment, the subject started to exercise again. This case study illustrates that unaccustomed exercise in the form of high-intensity resistance training may be harmful (ie, severe delayed onset muscle soreness or even worse, as reported in this case, rhabdomyolysis) to detrained athletes.

High‐Intensity Resistance Training with Insufficient Recovery Time Between Bouts Induce Atrophy and Alterations in Myosin Heavy Chain Content in Rat Skeletal Muscle

The aim of this study was to test whether high-intensity resistance training with insufficient recovery time between bouts, could result in a decrease of muscle fiber cross-sectional area (CSA), alter fiber-type frequencies and myosin heavy chain (MHC) isoform content in rat skeletal muscle. Wistar rats were divided into two groups: trained (Tr) and control (Co). Tr group were subjected to a high-intensity resistance training program (5 days/week) for 12 weeks, involving jump bouts into water, carrying progressive overloads based on percentage body weight. At the end of experiment, animals were sacrificed, superficial white (SW) and deep red (DR) portions of the plantaris muscle were removed and submitted to mATPase histochemical reaction and SDS-PAGE analysis. Throughout the experiment, both groups increased body weight, but Tr was lower than Co. There was a significant reduction in IIA and IID muscle fiber CSA in the DR portion of Tr compared to Co. Muscle fiber-type frequencies showed a reduction in Types I and IIA in the DR portion and IID in the SW portion of Tr compared to Co; there was an increase in Types IIBD frequency in the DR portion. Change in muscle fiber-type frequency was supported by a significant decrease in MHCI and MHCIIa isoforms accompanied by a significant increase in MHCIIb isoform content. MHCIId showed no significant differences between groups. These data show that high-intensity resistance training with insufficient recovery time between bouts promoted muscle atrophy and a transition from slow-to-fast contractile activity in rat plantaris muscle.

Regulators of Muscle Hypertrophy are Unaffected by Whey Protein and Casein Supplementation in Older Individuals

PURPOSE: To compare whey and casein protein combined with a 12-week resistance training program on systemic and cellular mechanisms regulating skeletal muscle hypertrophy in older males. METHODS: Thirty-six non-resistance trained males (62.5±6.8 yrs, 177±6.32 cm, 95.25±16.9 kg) were randomized in a double blind manner to ingest either whey protein (WP) [20g/d WP + 5g carbohydrate (CHO)], casein protein (CAS) (20g/d CAS + 5g CHO) or maltodextrose placebo (CHO) [25g/d CHO] while participating in a supervised high intensity resistance training program (3 sets x 10 repetitions at 75% of 1RM), 3 days per week for 12 weeks. Testing sessions were completed prior to (0 weeks), 4 weeks, 8 weeks and 12 weeks post resistance training and supplementation. Each testing session included blood collection and vastus lateralis muscle biopsy. The blood serum was analyzed for insulin-like growth factor 1 (IGF-1), free testosterone and hepatocyte growth factor (HGF) and the muscle tissue for phosphorylated mesenchymal-epithelial transition factor (c-Met). Data was analyzed using repeated measures ANOVA. RESULTS: A significant time effect was observed for serum free testosterone (0 weeks:14.26±9.78pg/ml vs. 12 weeks: 17.01±13.10pg/ml, p<0.05), with subsequent post-hoc analysis revealing significantly higher serum free testosterone levels at 4 weeks (18.61±15.20pg/ml, p=0.021) and 8 weeks (17.67±14.04pg/ml, p=0.028) compared to 0 weeks (14.26±9.78pg/ml). No time effects were evident for serum IGF-1 (0 weeks:0.841±0.487pg/ml vs. 12 weeks:0.824±0.448pg/ml, p=0.309), HGF (0 weeks:332.33±705.17pg/ml vs. 12 weeks:306.52±586.03pg/ml, p=0.483), or phosphorylated c-Met (0 weeks:0.109±0.242ng/mg vs. 12 weeks:0.038±0.039ng/mg, p=0.316). A significant group effect was observed for serum IGF-1 (p<0.05), with subsequent post-hoc analysis revealing significantly higher serum IGF-1 levels in the WP (0.684±0.381, p<0.05) and CAS groups (0.925±0.437, p<0.01) compared to CHO placebo (0.353±0.267). No other group or group by time interactions were observed. CONCLUSIONS: Whey protein and casein supplementation in conjunction with 12-weeks of resistance training were unable to enhance serum IGF-1 and testosterone levels and/or markers of satellite cell activation in older males.

Preoperative Strength Training for Patients Undergoing High Tibial Osteotomy: A Prospective Cohort Study With Historical Controls

Prospective cohort with historical controls. To examine the effects of a 12-week preoperative high-intensity resistance training program on postoperative outcomes. The primary goals of high tibial osteotomy (HTO) are to decrease pain and improve overall function during activities of daily living and participation in sport and recreation in relatively young, active individuals with knee osteoarthritis. However, the postoperative recovery typically requires a considerable period of protected weight-bearing that can result in substantial deficits in muscular strength. Fourteen patients (mean ± SD, 48.0 ± 7.8 years; 13 males, 1 females), scheduled for medial opening wedge HTO, completed a 12-week preoperative high-intensity isokinetic resistance training program focusing on quadriceps and hamstrings strength. These patients were matched to baseline clinical and demographic characteristics of 14 patients who previously received a medial opening wedge HTO without preoperative training. All outcomes were measured before and 6 months after surgery. The sport and recreation subscale of the Knee Injury and Osteoarthritis Outcome Score (KOOS) was the primary outcome of interest. Secondary outcomes included the other KOOS subscales, scores on the Lower Extremity Functional Scale, and selected kinematic and kinetic variables obtained from 3-dimensional gait analysis. The patients in the preoperative training group achieved significantly greater scores on the KOOS sport and recreation (mean ± SD, 58.6 ± 16.6 versus 42.1 ± 20.4; mean difference, 16.4; 95% CI: 2.0, 30.9) and activities of daily living (mean ± SD, 85.3 ± 9.3 versus 76.9 ± 12.0; mean difference, 8.4; 95% CI: 0.1, 16.8) subscales. There were no significant differences between groups on other outcomes. The present findings suggest preoperative high-intensity resistance training of the quadriceps and hamstrings before HTO improves postoperative functioning in sport, recreation, and activities of daily living. Therapy, level 2b.

Case Report

A majority of older adults with hip fracture retain longstanding disabilities following surgery. Research suggests that more aggressive treatment techniques can improve outcome. The purpose of this case report is to describe an evidence-based approach to guide physical therapy examination and intervention for a woman with significant frailty recovering from hip fracture. The patient is a 97-year-old woman residing in a skilled nursing facility 3 months status-postsurgical repair of an intertrochanteric hip fracture. She had received 2 1/2 months of physical therapy care using conventional interventions, however, had not regained her prefracture mobility status. She agreed to participate in a progressive high-intensity resistance training program over a 2-month period to augment her lower-extremity strength and function. The 5-day training regimen emphasized resistance training with a weighted belt twice-weekly with endurance and balance training interposed on nonstrength training days. The patient's goal was to return to community dwelling. Lower-extremity isometric force was measured using handheld dynamometry. Functional mobility was assessed via Timed Up and Go, Six-Minute Walk, Berg Balance, and gait speed tests. A 9-item Physical Performance Test gauged degree of frailty. Hip extension, hip abduction, and knee extension isometric force scores on the involved lower-extremity increased by 8 kg, 3 kg, and 7 kg, respectively. Balance, frailty, and gait speed indices improved from 14 to 45, 8 to 18, and 0.50 to 0.83 m/s, respectively. Prescribed high-intensity resistance training was used to improve the patient's functional status 2 months after completing a conventional physical therapy program.

Resistance Training for Medial Compartment Knee Osteoarthritis and Malalignment

1) To evaluate the effects of a 12-wk high-intensity knee extensor and flexor resistance training program on strength, pain, and adherence in patients with advanced knee osteoarthritis and varus malalignment and 2) to generate pilot data for change in dynamic knee joint load, patent-reported outcomes, and self-efficacy after training. Fourteen patients (48.35 +/- 6.51 yr) with radiographically confirmed medial compartment knee osteoarthritis and varus malalignment of the lower limb were recruited from a surgical waiting list for high tibial osteotomy. Participants completed a high-intensity isokinetic resistance training program three times per week for 12 wk. Knee extensor and flexor strength were assessed every third week, whereas pain and adherence were recorded at every training session. The external knee adduction moment during the gait, the 6-min-walk test, the Knee Injury and Osteoarthritis Outcome Score (KOOS), and the Arthritis Self-Efficacy Scale (ASES) were also evaluated before and after training. Significant improvements in knee extensor and flexor strength were observed without increases in pain during or after training. Adherence to the high-intensity program was high. No significant changes were observed for dynamic knee joint load or the KOOS. There was a significant increase in the function subscale of the ASES only. These findings suggest that patients with advanced knee osteoarthritis and malalignment can experience substantial gains in strength after a high-intensity resistance training program without concomitant increases in pain, adverse events, or compromised adherence. These findings provide support for future clinical trials with longer-term outcomes.

Influence of a High-Intensity Resistance Training Program on Muscular Strength in Coronary Patients

Patients enrolled in a traditional phase 3 cardiac rehabilitation often participate in moderate resistance training (RT) in conjunction with their endurance exercise regimen. Within our maintenance rehabilitation program, we developed an advanced RT program to further enhance strength and functional improvements in our patient population. PURPOSE: To assess relative changes in upper-and-lower body muscular strength during participation in our high-intensity RT program. METHODS: Clinically stable coronary patients (mean ± SD age = 61 ± 11.2 years) were required to meet strict program entry guidelines including ejection fraction > 45%. Small training groups (1-4 patients) met 3 days/week for one hour for a minimum of 1 month. Patients were tested for muscular strength on chest and leg press exercise machines using standard repetition maximum (RM) testing. Patients were retested on identical equipment for RM every 2 months during participation in the program. RESULTS: There were no adverse responses to testing or participation during high-intensity RT programs. Twenty patients consented and were tested for muscular strength. Selected baseline and serial testing data are shown in the table below:TableChange in weights lifted represent plates on Cybex training equipment (chest press=9 lb plates; leg press=12 lb plates). CONCLUSIONS: These data demonstrate improvements in muscular strength as measured by 1 -RM testing in cardiac patients enrolled in an advanced RT program. Significant muscular strength gains can be safely achieved following high-intensity RT programs in selected, clinically stable coronary patients.

Effects of High Intensity Resistance Training on Arterial Stiffness and Wave Reflection in Women

Cross-sectional studies reported that chronic resistance training is associated with arterial stiffening in men. These findings are in marked contrast to those found with aerobic exercise and may have important clinical relevance with regard to cardiovascular disease risk. However, the effect of resistance training on arterial stiffness has not been confirmed by interventional studies nor has this relation been investigated in women. To determine whether a strength training program increases regional and central arterial stiffness in women, 23 healthy young women (29+/-1 years; mean+/-SD) participated in a high-intensity strength and power training program for 11 weeks. Ten other women (27+/-2 years) served as time controls. In the intervention group, one repetition maximal strength increased 12% to 17% (P<.0001), and leg fat-free mass (via DEXA) increased significantly. Brachial blood pressure (BP) and fasting plasma lipid and lipoprotein concentrations did not change across the 11 weeks. Carotid augmentation index, a measure of arterial wave reflection and arterial stiffness, increased from -8%+/-13% to 1%+/-18% (P<.05), and carotid-femoral pulse wave velocity increased (791+/-88 v 833+/-96 cm/sec; P<.05). There were no changes in femoral-ankle pulse wave velocity, a segmental measure of peripheral arterial stiffness. We concluded that a high-intensity resistance training program increases arterial stiffness and wave reflection in young healthy women. Our present interventional results are consistent with the previous cross-sectional studies in men in which high-intensity strength training is associated with arterial stiffening.

The Effects of Strength Training on Arterial Stiffness in Women

0377 Cross-sectional studies reported that chronic resistance training is associated with arterial stiffening in men. These findings are in marked contrast to those found with aerobic exercise and may have important clinical relevance with regard to cardiovascular disease risk. However, the effect of resistance training on arterial stiffness has not been confirmed by interventional studies nor has this relation been investigated in women. PURPOSE: To determine if a short-term, high-intensity, progressive strength training program increases regional and central arterial stiffness in women. METHODS: Twenty-four healthy young women (30 ± 1 yrs) participated in a high intensity strength and power training program 90 min/day, 4 days/wk for 128 wks. Two days of the week were devoted to leg/trunk exercises and two days to upper body exercises. Heavy (85% 1 repetition maximum (RM), 8–10 reps × 3 sets) and light (65% 1 RM, 10 reps × 3 sets) exercises were performed each day. Ten other women (27 ± 2 yrs) served as time controls. Blood pressure and measures of arterial stiffness were obtained using a recently-validated automatic device (Colin VP-2000; Colin Medical, San Antonio, TX). RESULTS: One RMrepetition maximal strength increased between 12 and 17% (p < 0.0001)., L and leg fat-free mass (via DEXA) also increased significantly. Brachial blood pressure and fasting plasma lipid and lipoprotein concentrations did not change across the 128 wks. Carotid augmentation index, a measure of arterial wave reflection and arterial stiffness, increased from −8.3 ± 2.6 to 0.5 ± 3.5% (p < 0.05). There were no changes in carotid-femoral or femoralankle pulse wave velocity which are, segmental measures of central and peripheral arterial stiffness, respectively. There were no significant changes in any of the variables in the control group. CONCLUSIONS: A high intensity resistance training program increases amplification of arterial wave reflection that is associated with arterial stiffness in women. Our present interventional results are consistent with the previous cross-sectional studies indicating that high intensity strength training is associated with arterial stiffening. Supported by the Austin Fire Department, GSSI, and NIH grant AG20966

THE EFFECT OF HIGH INTENSITY RESISTANCE TRAINING ON ISOTONIC STRENGTH AMONG FEMALE COLLEGIATE BASKETBALL PLAYERS

Purpose: The purpose of this study was to examine the effect of a single-set, high intensity resistance training program on isotonic strength among female collegiate basketball players. Methods: Twelve healthy, moderately resistance trained female collegiate basketball players were randomly assigned to either a single-set, exhaustive high intensity (N = 6) or multiple-set (N = 6) group. Both groups performed heavy resistance exercise for 10 weeks. The high intensity group performed one set of 6–10 RM to volitional muscular fatigue for each exercise. The subjects were then urged to try additional repetitions until they were unsuccessful in completing a repetition. After this brief isometric contraction the set was terminated. The multiple-set group performed three sets of each exercise at 6–10 RM, but the subjects were not urged to try additional repetitions after volitional muscular fatigue. Isotonic strength data were collected at baseline and at 10 weeks by determining each subject's 1 RM leg press and bench press strength. The change in isotonic strength was compared within and between groups. Results: (reported by mean change ± SD): The change in 1 RM leg press and bench press strength (125.0 ± 33.5 lbs. and 12.5 ± 2.7 lbs., respectively) in the high intensity group was significant (p < 0.0001). The change in 1 RM leg press and bench press strength (20.8 ± 10.7 lbs. and 5.8 ± 5.8 lbs., respectively) in the multiple-set group was also significant (p < 0.03). The isotonic strength gains were significantly greater in the high intensity group than in the multiple-set group (p < 0.0002 and p < 0.02 for leg press and bench press, respectively). Conclusion: The data from this study indicate that a single-set, exhaustive high intensity resistance training program elicits superior gains in isotonic strength than does a multiple-set program among moderately resistance trained female collegiate basketball players.

THE EFFECTS OF 6-MONTHS OF AEROBIC EXERCISE OR HIGH INTENSITY RESISTANCE EXERCISE ON BODY MASS AND BODY COMPOSITION IN OVERWEIGHT MIDDLE AGE MEN

We compared the effects of 6-months of aerobic exercise vs. high intensity resistance exercise on body mass (BM), body fat percent (%Fat), and fat free mass (FFM) in 17 healthy, overweight, sedentary middle-age men. After baseline testing, subjects were randomly assigned to either an aerobic (n = 7; age, 36 ± 3; BMI, 31 ± 4) or resistance training (n = 10; age, 36 ± 6 y; BMI, 31 ± 4) group. All exercise sessions were supervised. The aerobic exercise program consisted of walking and/or jogging at an intensity that corresponded to 70–80% of maximal aerobic power and began at 3 d/wk for 20 m and progressed to 4 d/wk for 45 m by week 10. The resistance training consisted of a linearly periodized high intensity resistance training program designed to target all major muscle groups. Training began at 3 d and progressed to 4 d/wk for 45 min per session by week 10. Both groups completed 3 d dietary food recors at baseline and 6-months and were provided nutritional counseling and instructed to reduce caloric intake by approximately 500 kcal. BM was measured monthly with %Fat, and FFM measured at baseline and 6-months using a Lunar DEXA. There was no significant difference from baseline to 6 months in BM between groups, however the aerobic group significantly decreased BM from baseline (102.7 ± 10.4 kg) to 6 months (95.9 ± 6.9 kg). There was no significant change in %Fat between groups, but both groups experienced significant reductions in %Fat from baseline (resistance 36.0 ± 6.2%; aerobic 34.8 ± 6.3) to 6 months (resistance 34.4 ± 7.2%; aerobic 31.7 ± 6.4%). There was a significant decrease in FFM from baseline (66.7 ± 6.50 kg) to 6 months (65.4 ± 6.7 kg) in the aerobic group and a significant increase in FFM from baseline (63.8 ± 5.3) to 6 months (64.7 ± 5.5) in the resistance group. We concluded that for middle-aged males, aerobic exercise was effective in reducing BM, by decreasing both %Fat and FFM. Resistance exercise was not effective for reducing BM but does have a positive effect upon body composition, as indicated by a significant decrease in %Fat, and a significant increase in FFM. Funded by the American Heart Association #99511162.

A MINIMALISTIC MODEL OF RESISTANCE TRAINING: EFFECTS ON SKELETAL MUSCLE FUNCTION DURING UNLOADING

1657 Since astronaut time and energy are at a premium, effective countermeasure programs must be designed to maximize benefits while minimizing the time/energy cost. Therefore, our intent was to design and evaluate a low volume, high intensity resistance training program (RTP) on the preservation of knee extensor and plantar flexor strength and size in response to unloading. Eight men underwent 21 days of unilateral lower limb suspension (ULLS) and were assigned to no exercise (NE, n=4) or countermeasures (CM, n=4). CM was performed every third day over the 21 d period (total of 6 sessions). CM consisted of 2 maximal isometric contractions, 1 set of 10 concentric (CON) and eccentric (ECC) isotonic repetitions, and 1 set to exhaustion, at 80% of the CON 1-repetition maximum (1RM). Maximal CON and ECC 1RM strength and maximal isokinetic strength across 6 CON (1.05-8.73 rad·sec−1) and ECC velocities (1.05-5.24 rad·sec−1) were assessed. Knee extensor work capacity (WC) was evaluated during 30 maximal CON contractions at 3.14 rad·sec−1. Neural activation of v. lat, v. med, gast and sol was measured by electromyography (EMG). Muscle cross sectional area (CSA) was measured by computed tomography (CT). NE CON and ECC isokinetic strength decreased at all velocities (range. 13-30%) and peak isometric and 1RM strength declined 19% and 20%, respectively (p<0.05). CM showed no strength changes. Knee extensor WC decreased 15% in NE (p<0.05), and was unaltered in CM. Submaximal v. lat EMG increased and maximal v. lat, gast and sol EMG decreased in NE (p<0.05). CSA decreased 8% (quadricep) and 9% (calf) in NE, while no changes in CM were observed. These data suggest muscle strength and size are preserved during unloading using a low volume, high intensity RTP performed every third day. Supported by NASA and the Indiana Space Grant Consortium.

THE EFFECTS OF CHRONIC RESISTANCE TRAINING ON COMMUNITY DWELLING POST-MENOPAUSAL WOMEN WITH LOW BONE MINERAL DENSITY

967 The purpose of this study was to assess the effects of resistance training on dynamic strength, isokinetic strength, balance and the IGF system in post-menopausal women with low bone mineral density. Thirteen post-menopausal women including, seven who were osteopenic (66.9 years of age) and six who were osteoporotic (67.8 years of age) participated in a progressive high intensity resistance training program which included nine exercises targeting the lower extremities. There was a significant increase in dynamic strength for both the osteopenic (36-90%) and osteoporotic (58-105%) groups. Isokinetic strength also increase significantly in hip flexion and extension in the osteoporotic group (24.9 and 26.8% respectively), as well as hip extension for the osteopenic group (19.2%). Associated with these changes in strength were significant improvements in balance. Post training values for IGF-1 were significantly (P< 0.05) elevated above pre-training baseline values (osteopenic- +81%; osteoporotic- +52%) but there were no significant changes in IGFBP-3 or IGFBP-1 levels as a result of training. However there was a significant decrease in the BP-3/IGF-1 and BP-1/IGF-1 ratio indicating an increase in bioavailability of IGF-1 which may contribute to the significant increase in strength and balance in our subjects.