Self-selected resistance training intensity in novice weightlifters

The purpose of this study was to determine the intensity of self-selected weightlifting exercise in untrained men and women. Thirteen men (age = 19.5 +/- 1.9, height = 70.0 +/- 2.4 in., weight = 174 +/- 20.1 lb, % fat = 14.3 +/- 6.7) and 17 women (age =18.7 +/- 1.0, height = 64.9 +/- 2.3 in., weight = 135.4 +/- 22.8 lb, % fat= 23.4 +/- 4.7) who were novice lifters completed seated bench press, leg extension, seated back row, military press, and biceps curl. Following self-selection trials, subjects' 1 repetition maximum (1RM) was assessed for each lift. Results showed that for both genders, self-selected loads were all below 60% 1RM. All lift intensities were similar for men and women (range = 42-57% 1RM). Repetitions completed and rating of perceived exertion responses were not different between gender. Results show that subjects do not select a lifting intensity sufficient to induce hypertrophic responses and subsequent strength increases.     

Quantitation of resistance training using the session rating of perceived exertion method

The purpose of this study was to apply the session rating of perceived exertion (RPE) method, which is known to work with aerobic training, to resistance training. Ten men (26.1 +/- 10.2 years) and 10 women (22.2 +/- 1.8 years), habituated to both aerobic and resistance training, performed 3 x 30 minutes aerobic training bouts on the cycle ergometer at intensities of 56%, 71%, and 83% Vo(2) peak and then rated the global intensity using the session RPE technique (e.g., 0-10) 30 minutes after the end of the session. They also performed 3 x 30 minutes resistance exercise bouts with 2 sets of 6 exercises at 50% (15 repetitions), 70% (10 repetitions), and 90% (4 repetitions) of 1 repetition maximum (1RM). After each set the exercisers rated the intensity of that exercise using the RPE scale. Thirty minutes after the end of the bout they rated the intensity of the whole session and of only the lifting components of the session, using the session RPE method. The rated intensity of exercise increased with the %Vo(2) peak and the %1RM. There was a general correspondence between the relative intensity (%Vo(2) peak and % 1RM) and the session RPE. Between different types of resistance exercise at the same relative intensity, the average RPE after each lift varied widely. The resistance training session RPE increased as the intensity increased despite a decrease in the total work performed (p < 0.05). Mean RPE and session RPE-lifting only also grew with increased intensity (p < 0.05). In many cases, the mean RPE, session RPE, and session RPE- lifting only measurements were different at given exercise intensities (p < 0.05). The session RPE appears to be a viable method for quantitating the intensity of resistance training, generally comparable to aerobic training. However, the session RPE may meaningfully underestimate the average intensity rated immediately after each set.     

Monitoring exercise intensity during resistance training using the session RPE scale

This study investigated the reliability of the session rating of perceived exertion (RPE) scale to quantify exercise intensity during high-intensity (H), moderate-intensity (M), and low-intensity (L) resistance training. Nine men (24.7 +/- 3.8 years) and 10 women (22.1 +/- 2.6 years) performed each intensity twice. Each protocol consisted of 5 exercises: back squat, bench press, overhead press, biceps curl, and triceps pushdown. The H consisted of 1 set of 4-5 repetitions at 90% of the subject's 1 repetition maximum (1RM). The M consisted of 1 set of 10 repetitions at 70% 1RM, and the L consisted of 1 set of 15 repetitions at 50% 1RM. RPE was measured following the completion of each set and 30 minutes postexercise (session RPE). Session RPE was higher for the H than M and L exercise bouts (p < or = 0.05). Performing fewer repetitions at a higher intensity was perceived to be more difficult than performing more repetitions at a lower intensity. The intraclass correlation coefficient for the session RPE was 0.88. The session RPE is a reliable method to quantify various intensities of resistance training.     

Changes of muscular sound during sustained isometric contraction up to exhaustion

The sound (SMG) generated by the biceps muscle during isometric exercise at 20, 40, 60, and 80% of maximum voluntary contraction (MVC) up to exhaustion has been recorded by a contact transducer and integrated (iSMG), together with the surface electromyogram (EMG) in eight young untrained men. At the onset of exercise, iSMG and integrated surface EMG (iEMG) amplitude increased linearly with exercise. iSMG remained constant for 253 +/- 73 (SD), 45 +/- 16, 21 +/- 5, and 0 s at the four levels of contraction. Then iSMG increased linearly at 20% MVC, fluctuated at 40% MVC, and decreased exponentially at 60 and 80% MVC. iSMG exhaustion-to-onset ratio was 5.0 at 20%, 1.0 at 40%, and 0.2 at 60 and 80% MVC. On the contrary, independently of exercise intensity, iEMG increased with time, being 1.4 higher at exhaustion than at the onset. The nonunivocal iSMG changes with time and effort of exercise suggest that the sound may be a useful tool to acquire different information to EMG and output force during muscle contraction up to fatigue.     

Trunk muscle activation during dynamic weight-training exercises and isometric instability activities

The purpose of this study was to examine the extent of activation in various trunk muscles during dynamic weight-training and isometric instability exercises. Sixteen subjects performed squats and deadlifts with 80% 1 repetition maximum (1RM), as well as with body weight as resistance and 2 unstable calisthenic-type exercises (superman and sidebridge). Electromyographic (EMG) activity was measured from the lower abdominals (LA), external obliques (EO), upper lumbar erector spinae (ULES), and lumbar-sacral erector spinae (LSES) muscle groups. Results indicated that the LSES EMG activity during the 80% 1RM squat significantly exceeded 80% 1RM deadlift LSES EMG activity by 34.5%. The LSES EMG activity of the 80% 1RM squat also exceeded the body weight squat, deadlift, superman, and sidebridge by 56, 56.6, 65.5, and 53.1%, respectively. The 80% 1RM deadlift ULES EMG activity significantly exceeded the 80% 1RM squat exercise by 12.9%. In addition, the 80% 1RM deadlift ULES EMG activity also exceeded the body weight squat, deadlift, superman, and sidebridge exercises by 66.7, 65.5, 69.3, and 68.6%, respectively. There were no significant changes in EO or LA activity. Therefore, the augmented activity of the LSES and ULES during 80% 1RM squat and deadlift resistance exercises exceeded the activation levels achieved with the same exercises performed with body weight and selected instability exercises. Individuals performing upright, resisted, dynamic exercises can achieve high trunk muscle activation and thus may not need to add instability device exercises to augment core stability training.     

Muscle glycogenolysis during differing intensities of weight-resistance exercise

Skeletal muscle glycogen metabolism was investigated in eight male subjects during and after six sets of 70% one repetition maximum (1 RM, I-70) and 35% 1 RM (I-35) intensity weight-resistance leg extension exercise. Total force application to the machine lever arm was determined via a strain gauge and computer interfaced system and was equated between trials. Compared with the I-70 trial, the I-35 trial was characterized by almost double the repetitions (13 +/- 1 vs. 6 +/- 0) and half the peak concentric torque for each repetition (12.4 +/- 0.5 vs. 24.2 +/- 1.0 Nm). After the sixth set, muscle glycogen degradation was similar between I-70 and I-35 trials (47.0 +/- 6.6 and 46.6 +/- 6.0 mmol/kg wet wt, respectively), as was muscle lactate accumulation (13.8 +/- 0.7 and 16.7 +/- 4.2 mmol/kg wet wt, respectively). After 2 h of passive recovery without caloric intake, muscle glycogen increased by 22.2 +/- 6.8 and 14.2 +/- 2.5 mmol/kg wet wt in the I-70 and I-35 trials, respectively. Optical absorbance measurement of periodic acid-Schiff-stained muscle sections after the 2 h of recovery revealed larger absorbance increases in fast-twitch than in slow-twitch fibers (0.119 +/- 0.024 and 0.055 +/- 0.024, P = 0.02). Data indicated that when external work was constant, the absolute amount of muscle glycogenolysis was the same regardless of the intensity of resistance exercise. Nevertheless the rate of glycogenolysis during the I-70 trial was approximately double that of the I-35 trial.     

Comparison of low- and high-intensity resistance exercise on lipid peroxidation: role of muscle oxygenation

The purpose of this study was to examine the effect of low- vs. high-intensity resistance exercise on lipid peroxidation. In addition, the role of muscle oxygenation on plasma malondialdehyde (MDA) concentrations was explored. Eleven experienced resistance trained male athletes (age: 20.8 +/- 1.3 years; weight: 96.2 +/- 14.4 kg; height: 182.4 +/- 7.3 cm) performed 4 sets of the squat exercise using either a low-intensity, high-volume (LI; 15 repetitions at 60% 1 repetition maximum [1RM]) or high-intensity, low-volume (HI; 4 repetitions at 90% 1RM load). Venous blood samples were obtained before the exercise (PRE), immediately following the exercise (IP), and 20 (20P) and 40 minutes (40P) postexercise. Continuous wave near-infrared spectroscopy was used to measure muscle deoxygenation in the vastus lateralis during exercise. Deoxygenated Hb/Mb change was used to determine reoxygenation rate during recovery. No difference in MDA concentrations was seen between LI and HI at any time. Significant correlations were observed between plasma MDA concentrations at IP and the half-time recovery (T1/2 recovery) of muscle reoxygenation (r = 0.45) and between T1/2 recovery and the area under the curve for MDA concentrations (r = 0.44). Results suggest that increases in MDA occur independently of exercise intensity, but tissue acidosis may have a larger influence on MDA formation.     

No difference in 1RM strength and muscle activation during the barbell chest press on a stable and unstable surface

Exercise or Swiss balls are increasingly being used with conventional resistance exercises. There is little evidence supporting the efficacy of this approach compared to traditional resistance training on a stable surface. Previous studies have shown that force output may be reduced with no change in muscle electromyography (EMG) activity while others have shown increased muscle EMG activity when performing resistance exercises on an unstable surface. This study compared 1RM strength, and upper body and trunk muscle EMG activity during the barbell chest press exercise on a stable (flat bench) and unstable surface (exercise ball). After familiarization, 13 subjects underwent testing for 1RM strength for the barbell chest press on both a stable bench and an exercise ball, each separated by at least 7 days. Surface EMG was recorded for 5 upper body muscles and one trunk muscle from which average root mean square of the muscle activity was calculated for the whole 1RM lift and the concentric and eccentric phases. Elbow angle during each lift was recorded to examine any range-of-motion differences between the two surfaces. The results show that there was no difference in 1RM strength or muscle EMG activity for the stable and unstable surfaces. In addition, there was no difference in elbow range-of-motion between the two surfaces. Taken together, these results indicate that there is no reduction in 1RM strength or any differences in muscle EMG activity for the barbell chest press exercise on an unstable exercise ball when compared to a stable flat surface. Moreover, these results do not support the notion that resistance exercises performed on an exercise ball are more efficacious than traditional stable exercises.     

Magnetic resonance imaging and electromyography as indexes of muscle function.

Electromyography (EMG) is commonly used to determine the electrical activity of skeletal muscle during contraction. To date, independent verification of the relationship between muscle use and EMG has not been provided. It has recently been shown that relaxation- (e.g., T2) weighted magnetic resonance images (MRI) of skeletal muscle demonstrate exercise-induced contrast enhancement that is graded with exercise intensity. This study was conducted to test the hypothesis that exercise-induced magnetic resonance (MR) contrast shifts would relate to EMG amplitude if both measures reflect muscle use during exercise. Both MRI and EMG data were collected for separate eccentric (ECC) and concentric (CON) exercise of increasing intensity to take advantage of the fact that the rate of increase and amplitude of EMG activity are markedly greater for CON muscle actions. Seven subjects 30 +/- 2 (SE) yr old performed five sets of 10 CON or ECC arm curls with each of four resistances representing 40, 60, 80, and 100% of their 10 repetition maximum for CON curls. There was 1.5 min between sets and 30 min between bouts (5 sets of 10 actions at each relative resistance). Multiple echo, transaxial T2-weighted MR images (1.5 T, TR/TE 2,000/30) were collected from a 7-cm region in the middle of the arm before exercise and immediately after each bout. Surface EMG signals were collected from both heads of the biceps brachii and the long head of the triceps brachii muscles. CON and ECC actions resulted in increased integrated EMG (IEMG) and T2 values that were strongly related (r = 0.99, P < 0.05) with relative resistance.(ABSTRACT TRUNCATED AT 250 WORDS)     

Training state improves the relationship between rating of perceived exertion and relative exercise volume during resistance exercises

ABSTRACT: Testa, M, Noakes, TD, and Desgorces, F-D. Training state improves the relationship between rating of perceived exertion and relative exercise volume during resistance exercises. J Strength Cond Res 26(11): 2990-2996, 2012-The aim of this study was to investigate how the rating of perceived exertion (RPE) during resistance exercises was influenced by the exercise volume and athletes' training state. Eighty physical education students (well trained, less well trained, and novices) rated their perceived exertion of multilift sets using the category-ratio scale. These sets were performed with moderate (60-80% of 1-repetition maximum [1RM]) and heavy loads (80-100% of 1RM) involving low volume of exercise (5.5 ± 1.1 reps for moderate and 1.3 ± 0.4 reps for the heavy load) and high volume of exercise (moderate load: 17.5 ± 2.1 reps; high load: 2.9 ± 0.6 reps). The exercise volume of the sets was expressed relatively to individual maximal capacities using the maximum number of repetition (MNR) for the load lifted. General linear model describes that RPE was related to MNR % with a training state effect (p < 0.01) observed only for sets involving a low MNR % and without effect of absolute volume and exercise intensity (high MNR sets: adjusted R = 0.65 and 0.78 and low MNR sets adjusted R = 0.37 and 0.34 in low MNR tests). High standard errors of estimated relative volume appeared when using the RPE from low exercise volume sets (12.8 and 14.4% of actual relative volume). Coaches should consider the RPE resulting from high exercise-induced physical strain to estimate the actual relative volume and to estimate the individual MNR at a given load.     

Strength changes during an in-season resistance-training program for football

The purpose of this study was to examine the effects of both intensity and volume of training during a 2 d.wk(-1) in-season resistance-training program (RTP) for American football players. Fifty-three National Collegiate Athletic Association Division III football players were tested in the 1 repetition maximum (1RM) bench press and 1RM squat on the first day of summer training camp (PRE) and during the final week of the regular season (POST). Subjects were required to perform 3 sets of 6-8 repetitions per exercise. Significant strength improvements in squat were observed from PRE (155.0 +/- 31.8 kg) to POST (163.3 +/- 30.0 kg), whereas no PRE to POST changes in bench press were seen (124.7 +/- 21.0 kg vs.123.9 +/- 18.6 kg, respectively). Training volume and training compliance were not related to strength improvement. Further analysis showed that athletes training at >or=80% of their PRE 1RM had significantly greater strength improvements than athletes training at <80% of their PRE 1RM, for both bench press and squat. Strength improvements can be seen in American football players, during an in-season RTP, as long as exercise intensity is >or=80% of the 1RM.     

Energy cost of moderate-duration resistance and aerobic exercise

The purpose of this study was to compare energy expenditure of resistance and aerobic exercise matched for total time and relative intensity. Ten trained men (24.3 +/- 3.8 years) performed 30 minutes of intermittent free-weight squatting at 70% of 1 repetition maximum and continuous cycling at 70% of Vo(2)max, in a crossover design. Vo(2), kilocalories (kcal), work, respiratory exchange ratio (RER), V(E), heart rate (HR), and rating of perceived exertion (RPE) data were recorded. Cycling resulted in greater total Vo(2) (87 +/- 3 vs. 53 +/- 3 L, mean +/- SEM), kcal expenditure (441 +/- 17 vs. 269 +/- 13), and work (335 +/- 11 vs. 128 +/- 11 kJ) than squatting did. The mean RER was greater during squatting (1.03 +/- 0.01 vs. 0.94 +/- 0.01), and the V(E) values were greater during cycling (82 +/- 3 vs. 70 +/- 3 L.min(-1)). The HR response was nearly identical between exercise modes (160 +/- 5 vs. 160 +/- 4 bpm), whereas the RPE was greater during squatting (16.96 +/- 0.41 vs. 14.88 +/- 0.42). These data suggest that although lower than similarly matched aerobic exercise, resistance exercise resulted in an energy cost that would meet the recommendations for kcal expenditure as suggested by the American College of Sports Medicine, if performed 4-5 days per week. These findings should be considered by coaches and trainers working with individuals mutually interested in muscular development and weight management, because programs of structured resistance exercise may assist with both.     

Endurance capacity of untrained males and females in isometric and dynamic muscular contractions

The capacity to perform isometric and dynamic muscle contractions at different forces has been measured in two separate groups of subjects: 25 men and 25 women performed sustained isometric contractions of the knee-extensor muscles of their stronger leg to fatigue, at forces corresponding to 80%, 50% and 20% of the maximum voluntary force of contraction (MVC). The second experimental model involved a bilateral elbow-flexion weight lifting exercise. Eleven women and 12 men performed repetitions at loads corresponding to 90%, 80%, 70%, 60% and 50% of maximum load (1RM), at a rate of 10 X min-1 to the point of fatigue. Males were stronger (p less than 0.001) than females in both the static (675 +/- 120 N vs 458 +/- 80 N; mean +/- SD) and dynamic (409 +/- 90 N vs 190 +/- 33 N) contractions. Isometric endurance time of the males at a force corresponding to 20% of MVC was less than that of the females (180 +/- 51 s vs 252 +/- 56 s; p less than 0.001) but there was no difference between the sexes at 50% or 80% of MVC. Similarly, when the sexes were compared using dynamic elbow-flexion exercise, the female subjects were able to perform a greater number of repetitions than males at loads of 50% (p less than 0.005), 60% (p less than 0.001) and 70% (p less than 0.025) of 1RM, but there was no difference between the sexes at loads of 80% or 90% of 1RM.(ABSTRACT TRUNCATED AT 250 WORDS)     

Estimation of peak vertical velocity and relative load changes by subjective measures in weightlifting movements

To investigate the ability of the OMNI-RES (0–10) scale to estimate velocity and loading changes during sets to failure in the hang power clean (HPC) exercise. Eleven recreationally resistance-trained males (28.5 ± 3.5 years) with an average one-repetition maximum (1RM) value of 1.1 ± 0.07 kg body mass^-1 in HPC, were assessed on five separate days with 48 hours of rest between sessions. After determining the 1RM value, participants performed four sets to self-determined failure with the following relative loading ranges: 60% < 70%, 70 < 80%, 80 < 90% and > 90%. The peak vertical velocity (PVV), and Rating of Perceived Exertion (RPE) were measured for every repetition of each set. The RPE expressed after the first repetition (RPE-1) and when the highest value of PVV was achieved during the set (RPE-max) were similar and significantly lower than the RPE associated with a 5% (RPE-5%) and 10% (RPE-10%) drop in PVV. In addition, the RPE produced at failure was similar to RPE-5% only for the heaviest range (≥ 90%). Furthermore, RPE-1 was useful to distinguish loading zones between the four assessed ranges (60 < 70%, vs. 70 < 80%, vs. 80 < 90%, vs. ≥ 90%). The RPE seems to be useful to identify PVV changes (maximal, 5% and 10% drop) during continuous sets to self-determined failure and to distinguish 10% loading zone increments, from 60 to 100% of 1RM in the HPC exercise.     

Influence of exercise order on the number of repetitions performed and perceived exertion during resistance exercise in women

The purpose of this study was to investigate the influence of different resistance exercise orders on the number of repetitions performed to failure and on the ratings of perceived exertion (RPE) in trained women. Twenty-three women with a minimum of 2 years of resistance training experience volunteered to participate in the study (age, 24.2 +/- 4.5 years; weight, 56.9 +/- 4.7 kg; height, 162.3 +/- 5.9 cm; percent body fat, 18.2 +/- 2.9%; body mass index, 22.2 +/- 2 kg x m(-2)). Data were collected in 2 phases: (a) determination of a 1 repetition maximum (1RM) for the leg-press (LP), bench press (BP), leg extension (LE), seated machine shoulder press (SP), leg curl (LC), and seated machine triceps extension (TE); and (b) execution of 3 sets, with 2-minute rest intervals between sets and exercises, until fatigue using 80% of 1RM in 2 exercise sequences of the exact opposite order--Sequence A: BP, SP, TE, LP, LE, and LC, and Sequence B: LC, LE, LP, TE, SP, and BP. The RPE (Borg CR-10) was accessed immediately after each sequence and analyzed using a Wilcoxon test. A 2-way analysis of variance with repeated measurements, followed by a post hoc Fisher least significant difference test where indicated was used to analyze the number of repetitions per set of each exercise during the 2 sequences. The RPE was not significantly different between the sequences. The mean number of repetitions per set was always less when an exercise was performed later in the exercise sequence. The data indicate that in trained women, performance of both large- and small-muscle group exercises is affected by exercise sequence.     

The effect of resistance-training intensity on strength-gain response in the older adult

This study examined how training intensity affects strength gains in older adults over an 18-week training period using nonperiodized, progressive resistance-training protocols. Untrained men and women participants were separated into 4 groups: group A (n = 17, 71.4 +/- 4.6 years) performed 2 sets of 15 repetitions maximum (RM), group B (n = 13, 71.5 +/- 5.2 years) performed 3 sets of 9 RM, group C (n = 17, 69.4 +/- 4.4 years) performed 4 sets of 6 RM, group D (n = 14, 72.3 +/- 5.9 years) served as controls. Training groups exercised 2 days/week performing 8 resistance exercises. Except for training intensity, the acute program variables were equated between groups. A 1RM for 8 exercises was obtained every 6 weeks. The total of 1RM for the 8 exercises served as the dependent variable. Results: repeated measures analysis of variance (ANOVA) and Scheffe post hoc revealed that, at 6 weeks, only groups B and C were significantly stronger than group D (p < 0.01). By weeks 12 and 18, all training groups were significantly stronger than controls (p < 0.01). However, no difference existed between groups A, B, and C at any time. The data suggests that, for protocols with equated acute program variables, strength gain is similar over 18 weeks for training intensities ranging from 6 to 15 RM in previously untrained older adults. When programming nonperiodized, progressive resistance exercise for novice senior lifters, in the initial phases of the program, a wide range of intensities may be employed with similar strength gain.     

Effects of exercise order on upper-body muscle activation and exercise performance

With the purpose of manipulating training stimuli, several techniques have been employed to resistance training. Two of the most popular techniques are the pre-exhaustion (PRE) and priority system (PS). PRE involves exercising the same muscle or muscle group to the point of muscular failure using a single-joint exercise immediately before a multi-joint exercise (e.g., peck-deck followed by chest press). On the other hand, it is often recommended that the complex exercises should be performed first in a training session (i.e., chest press before peck-deck), a technique known as PS. The purpose of the present study was to compare upper-body muscle activation, total repetitions (TR), and total work (TW) during PRE and PS. Thirteen men (age 25.08 +/- 2.58 years) with recreational weight-training experience performed 1 set of PRE and 1 set of PS in a balanced crossover design. The exercises were performed at the load obtained in a 10 repetition maximum (10RM) test. Therefore, chest press and peck-deck were performed with the same load during PRE and PS. Electromyography (EMG) was recorded from the triceps brachii (TB), anterior deltoids, and pectoralis major during both exercises. According to the results, TW and TR were not significantly different (p > 0.05) between PRE and PS. Likewise, during the peck-deck exercise, no significant (p > 0.05) EMG change was observed between PRE and PS order. However, TB activity was significantly (p < 0.05) higher when chest press was performed after the peck-deck exercise (PRE). Our findings suggest that performing pre-exhaustion exercise is no more effective in increasing the activation of the prefatigued muscles during the multi-joint exercise. Also, independent of the exercise order (PRE vs. PS), TW is similar when performing exercises for the same muscle group. In summary, if the coach wants to maximize the athlete performance in 1 specific resistance exercise, this exercise should be placed at the beginning of the training session.     

Serum and urinary markers of skeletal muscle tissue damage after weight lifting exercise

The purpose of this study was to determine whether high intensity weight lifting exercise produces elevations of urinary 3-methylhistidine (3-MH), serum creatine kinase activity (CK), and serum myoglobin concentration (MY), and whether trained weight lifters differed in such responses when compared to a group of untrained subjects. Ten experienced male weight lifters (EWL) and seven untrained male subjects (IWL) performed three sets of six weight lifting exercises at 70%-80% of 1 RM. All subjects consumed a meat-free diet. The 3-MH:creatinine (3-MH:CR) values decreased 24 h and 48 h following exercise (P less than 0.05). The 12-h and 24-h postexercise CK response and the 12-h postexercise MY response increased for both EWL and IWL (P less than 0.05). However, EWL had a lower 24-h postexercise CK response and lower 12-h and 24-h postexercise MY responses compared to IWL (P less than 0.05). Within 48 h following weight lifting exercise, skeletal muscle protein degradation (as assessed by 3-MH:CR values) decreased regardless of prior training experience whereas skeletal muscle tissue damage (as assessed by CK and MY responses) increased. However, prior weight lifting training appeared to diminish the extent of muscle tissue damage.