The effectiveness of 0.5-lb increments in progressive resistance exercise.

A traditional progressive resistance exercise program consists of increasing the number of repetitions at a constant load until exceeding an established repetition range. Subsequently, the load is increased by 1.1 kg (2.5 lb) or more, and the lifter works at the new load until again exceeding the repetition range. This investigation examines the use of small incremental loads for 2 upper-body exercises (bench press and triceps press). Subjects were randomly assigned to traditional (TRAD) progressive resistance exercise (5 women, 5 men) and small increment (SI) progressive resistance exercise (5 women, 4 men) groups. Initially, both groups trained for 8 weeks using TRAD progressive resistance exercise. Subjects who achieved 7 repetitions on the final set of an exercise increased the load for the next session by 2.2 (bench press) or 1.1 kg (triceps press). Following the initial 8-week training period, the TRAD group continued for another 8 weeks following the same protocol, whereas the SI group trained for an additional 8 weeks, increasing the load by 0.22 kg (0.5 lb) when completing 7 or 8 repetitions and 0.44 kg (1 lb) when achieving 9 or more repetitions. All groups, except TRAD women, made significant increases in 1 repetition maximum (1RM) for the bench press. Both TRAD men and SI men significantly increased 1RM triceps press. Groups that did not significantly increase 1RM, in either the bench press or triceps press, demonstrated similar trends. For TRAD men and SI men, the number of repetitions to failure for the bench press at 60% 1RM decreased after training. Both regimens proved effective for increasing strength throughout 8 weeks. In conclusion, SI progressive resistance exercise appears to be as effective as TRAD progressive resistance exercise for increasing strength during 8 weeks in short-term pretrained college-aged men and women. However, preliminary data suggest that the TRAD progressive resistance exercise program might be a more effective method of increasing resistance during an extended period.

Skeletal muscle adaptations in elastic resistance-trained young men and women.

Skeletal muscle adaptations (fiber-type composition, cross-sectional area, myosin heavy chain (MHC) content, and capillarity) were assessed in the vastus lateralis muscle of young men and women after 8 weeks of training with the Sportcord, an elastic resistance device. Ten men [mean (SD) age 20 (1.1) years] and 13 women [20 (1.2) years] performed two sets each to failure of single leg squats and leg extensions at approximately 50 repetitions x min(-1). Biopsy samples were taken from the right vastus lateralis muscle before and after training. Six fiber types (I, IC, IIC, IIA, IIAB, and IIB) were classified using myofibrillar ATPase histochemistry. Training with the Sportcord caused a small, but significant, increase in one-repetition maximum using free weights and a large increase in repetitions to failure. In addition, elastic resistance training caused an increase in the percentage of fibers classified as type IIAB for both men and women, and a decrease in the percentage of type IIB fibers in the men. MHC analysis supported these findings (a significant increase in the percentage of MHCIIa for the men). The cross-sectional areas ofboth the type I and IIAB + IIB fibers increased after training for the men, whereas no area changes were found for the women. The capillary:fiber ratio and capillary contacts per fiber type increased significantly for the men, and similar trends were noted for the women. Capillary density did not change in either the men or the women. These data suggest minor changes in fiber type composition (IIB-->IIAB), fiber size, and capillarization following short-term training with elastic resistance. Although muscular changes did occur using the Sportcord, the extent of these changes was less than those reported previously for short-term resistance-training programs using free weights.

Effects of high-intensity resistance training on untrained older men. I. Strength, cardiovascular, and metabolic responses.

Most resistance training studies of older subjects have emphasized low-intensity, short-term training programs that have concentrated on strength measurements. The purpose of this study was, in addition to the determination of strength, to assess intramuscular and transport factors that may be associated with strength increments. Eighteen untrained men ages 60-75 years volunteered for the study; 9 were randomly placed in the resistance-training group (RT), and the other half served as untrained (UT) or control subjects. RT subjects performed a 16-week high-intensity (85-90% 1 repetition maximum (RT]) resistance training program (2 x/wk) consisting of 3 sets each to failure (6-8 repetitions based on 1 RM of 3 exercises): leg press (LP), half squat (HS), and leg extension (LE) with 1-2 minutes rest between sets. Pre- and post- training strength was measured for the 3 training exercises using a 1 RM protocol. Body fat was calculated using a 3-site skinfold method. Biopsies from the vastus lateralis m. were obtained for fiber type composition, cross-sectional area, and capillarization measurements. Exercise metabolism, electrocardiography, and arterial blood pressure were observed continuously during a progressive treadmill test, and resting echocardiographic data were recorded for all subjects. Pre- and post-training venous blood samples were analyzed for serum lipids. Resistance training caused significant changes in the following comparisons: % fat decreased in the RT group by almost 3%, strength improved for all exercises: LE = + 50.4%, LP = + 72.3%, HS = + 83.5%; type IIB fibers decreased and IIA fibers increased; cross-sectional areas of all fiber types (I, IIA, IIB) increased significantly, and capillary to fiber ratio increased but not significantly. No differences were noted for ECG and echocardiographic data. The RT group significantly improved treadmill performance and VO2max. Pre- and post-training serum lipids improved but not significantly. No significant changes occurred in any pre- to post-tests for the UT group. The results show that skeletal muscle in older, untrained men will respond with significant strength gains accompanied by considerable increases in fiber size and capillary density. Maximal working capacity, VO2max, and serum lipid profiles also benefited from high-intensity resistance training, but no changes were observed for HR max, or maximal responses of arterial blood pressure. Older men may not only tolerate very high intensity work loads but will exhibit intramuscular, cardiovascular, and metabolic changes similar to younger subjects.

Effects of high-intensity resistance training on untrained older men. II. Muscle fiber characteristics and nucleo-cytoplasmic relationships.

During growth and repair of skeletal muscle fibers, satellite cells become activated, undergo mitosis, and a daughter nucleus becomes incorporated into the muscle fiber to increase myonuclear numbers. An increase in myonuclei appears to be required for this postnatal growth. This study examined whether muscle fibers of elderly men can hypertrophy with strength training and, if so, whether they have the capacity to incorporate nuclei into the fibers. The sarcoplasmic area associated with each myonucleus was calculated in nine elderly men before and after 16 weeks of strength training, and compared to nine elderly control men. Muscle fiber type changes and myosin heavy chain composition were also compared. All major fiber types (I, IIA, IIB) became significantly larger after training, and a transition of type IIB fibers to IIA occurred with training. The area occupied by each fiber type correlated with myosin heavy chain percentage, and both of these changed similarly with strength training. The cytoplasm-to-myonucleus ratio increased, but not significantly (p = .07), with muscle fiber hypertrophy. Number of myonuclei per fiber and myonuclei per unit length of muscle fiber increased, but not significantly. Cross-sectional areas of the muscle fibers in untrained elderly men were much smaller than in untrained young men (when compared with our earlier studies). Training increased the sizes of the elderly muscle fibers to that of the untrained young men. This hypertrophy of muscle fibers by 30% with training resulted in no change in the cytoplasm-to-myonucleus ratio. This suggests that the myonuclear population continues to adapt to growth stimuli in the elderly muscles.

Fiber type composition of the vastus lateralis muscle of young men and women.

This study presents data collected over the past 10 years on the muscle fiber type composition of the vastus lateralis muscle of young men and women. Biopsies were taken from the vastus lateralis muscle of 55 women (21.2+/-2.2 yr) and 95 men (21.5+/-2.4 yr) who had volunteered to participate in various research projects. Six fiber types (I, IC, IIC, IIA, IIAB, and IIB) were classified using mATPase histochemistry, and cross-sectional area was measured for the major fiber types (I, IIA, and IIB). Myosin heavy chain (MHC) content was determined electrophoretically on all of the samples from the men and on 26 samples from the women. With the exception of fiber Type IC, no significant differences were found between men and women for muscle fiber type distribution. The vastus lateralis muscle of both the men and women contained approximately 41% I, 1% IC, 1% IIC, 31% IIA, 6% IIAB, and 20% IIB. However, the cross-sectional area of all three major fiber types was larger for the men compared to the women. In addition, the Type IIA fibers were the largest for the men, whereas the Type I fibers tended to be the largest for the women. Therefore, gender differences were found with regard to the area occupied by each specific fiber type: IIA>I>IIB for the men and I>IIA>IIB for the women. These data establish normative values for the mATPase-based fiber type distribution and sizes in untrained young men and women.

The effects of short-term resistance training on endocrine function in men and women.

This investigation examined hormonal adaptations to acute resistance exercise and determined whether training adaptations are observed within an 8-week period in untrained men and women. The protocol consisted of a 1-week pre-conditioning orientation phase followed by 8 weeks of heavy resistance training. Three lower-limb exercises for the quadriceps femoris muscle group (squat, leg press, knee extension) were performed twice a week (Monday and Friday) with every other Wednesday used for maximal dynamic 1 RM strength testing. Blood samples were obtained pre-exercise (Pre-Ex), immediately post-exercise (IP), and 5 min post-exercise (5-P) during the first week of training (T-1), after 6 weeks (T-2) and 8 weeks (T-3) of training to determine blood concentrations of whole-blood lactate (LAC), serum total testosterone (TT), sex-hormone binding globulin (SHBG), cortisol (CORT) and growth hormone (GH). Serum TT concentrations were significantly (P < or = 0.05) higher for men at all time points measured. Men did not demonstrate an increase due to exercise until T-2. An increase in pre-exercise concentrations of TT were observed both for men and women at T-2 and T-3. No differences were observed for CORT between men and women; increases in CORT above pre-exercise values were observed for men at all training phases and at T-2 and T-3 for women. A reduction in CORT concentrations at rest was observed both in men and women at T-3. Women demonstrated higher pre-exercise GH values than men at all training phases; no changes with training were observed for GH concentrations. Exercise-induced increases in GH above pre-exercise values were observed at all phases of training. Women demonstrated higher serum concentrations of SHBG at all time points. No exercise-induced increases were observed in men over the training period but women increased SHBG with exercise at T-3. SHBG concentrations in women were also significantly higher at T-2 and T-3 when compared to T-1 values. Increases in LAC concentrations due to exercise were observed both for men and women for all training phases but no significant differences were observed with training. These data illustrate that untrained individuals may exhibit early-phase endocrine adaptations during a resistance training program. These hormonal adaptations may influence and help to mediate other adaptations in the nervous system and muscle fibers, which have been shown to be very responsive in the early phase of strength adaptations with resistance training.

Differential titin isoform expression in human skeletal muscle.

Mammalian skeletal muscle expresses at least two isoforms of the cytoskeletal protein titin (connectin; MW approximately 3000 kDa). These isoforms are associated with different passive force curves, and thus may affect physical performance. To study the distribution of titin and its possible influence on performance in humans, muscle biopsies were obtained from 15 males (mean +/- SE; age = 25.4 +/- 2.9 years, height = 177.7 +/- 1.8 cm, weight = 76.5 +/- 2.2 kg). Two biopsies were obtained on separate occasions from both the right and left vastus lateralis, and one biopsy each from the lateral head of the right gastrocnemius and the right soleus, with all biopsies handled identically. Fibre type analyses were performed via mATPase histochemistry. Expression of titin and myosin heavy chain isoforms were determined by SDS-PAGE. Titin bands in the resulting gels were highly repeatable and were verified by migration patterns, as well as Western blot analysis. Two groups of subjects were identified: group 1 (n = 10) expressed only one titin isoform (titin-1) in all biopsies, and group 2 (n = 5) expressed two titin isoforms (titin-1 and titin-2) in all biopsies. No significant differences (P > 0.05) between groups were observed for percentage fibre types, percentage fibre type areas, fibre type cross-sectional areas, and percentage myosin heavy chain expression when comparing individual muscles, sampling times or bilateral comparisons. This is the first report of differential titin isoform expression in healthy, mature human skeletal muscle, but it is not clear why this occurs or what influence this may have on performance.

A 20-yr longitudinal study of Olympic oarsmen.

Nine 1972 silver-medalist oarsmen were studied before the Olympic Games and 10 and 20 yr later. Peak power, metabolic responses, and heart rate were recorded during rowing ergometry; blood lactate was measured following exercise. The skinfold equation yielded percent body fat. The average change (multiple analysis of variance) among measurements from 1972 to 1992 was 37.5 +/- 3% (P < 0.01). Average changes between 1972 and 1982 and between 1982 and 1992 were similar, 17 and 18%, respectively (P < 0.01). The most significant change between 1972 and 1992 was decreased peak blood lactate (106%). Decreases in peak power, VE, and VO2 (ml.kg-1.min-1) were all similar, approximately 40%, and were significant. Body fat increased (from 12.3 to 15.6%), and absolute VO2 and relative VO2 (lean body mass) decreased 30% (P < 0.01). Only body weight, heart rate, and O2 pulse showed smaller changes, but these changes were still significant (P < 0.05). Relative peak VO2 decreased from 65.5 to 46.8 ml.kg-1.min-1 from 1972 to 1992 and at a rate of 10%.decade-1. The most significant changes between 1972 and 1982 were increases in percent body fat (from 12.3 to 16.3%) and decreases in VO2 values (P < 0.01). There was less change in body fat between 1982 and 1992, but lactate significantly decreased (P < 0.01), as did peak power and absolute and relative VO2 and VE. Although fitness levels in former elite oarsmen decreased each decade, these declines were somewhat arrested by regular aerobic training. Body fat increased and metabolic capacity decreased rapidly during the first decade, whereas anaerobic capacity decreased more significantly in the second decade. Anaerobic capacity diminished at a significantly greater rate than aerobic capacity, probably as a result of the aging process and emphasis on aerobic training in post-competitive years.

Cardiorespiratory and metabolic adaptations to hyperoxic training.

This study examined the effects of hyperoxic training on specific cardiorespiratory and metabolic responses. A group of 19 male subjects trained for 5 weeks on a cycle ergometer at 70 percent of hyperoxic or normoxic maximal heart rate, the hyperoxic group (HG) breathing 70 percent O2, the normoxic group (NG) breathing 21 percent O2. The subjects were tested pre- and post-training under both hyperoxia and normoxia. Measurements included cardiac output (Q(c)), stroke volume (SV), heart rate (HR), pulmonary ventilation (V(E)), oxygen consumption (VO(2)), partial pressure of oxygen (PO(2)), partial pressure of inspired carbon dioxide (PCO(2)), blood lactate concentration [La], and fiber type composition. The V(E) was significantly lower at submaximal work rates (P <0.05) and maximal V(E) increased after training in both groups for both test conditions; hyperoxic V(E) was lower than normoxic V(E) (P <0.05). The maximal V0(2) increased significantly (P <0.05) in both groups for both tests and was 11 percent - 12 percent higher during hyperoxia. Post-training maximal heart rate (HR(max)) was significantly decreased (P <0.05) at the same absolute work rate regardless of the training group or test type. The SV was increased at each work rate and Q c was unchanged. The maximal Q(c) increased significantly (P <0.05) for both groups and types of test: for normoxia: NG 27.3-30.41*min(-1) and HG 30.3-32.31*min(-1) and for hyperoxia: NG 24.7-25.6 and HG 27.9-31.21*min(-1). Although working at the same intensity relative to HR(max), HG showed significantly lower [La] following a single training session, yet maximal values were unchanged after training. Both groups showed a significant increase in the percentage of type IIA fibers post-training but HG retained a larger percentage of IIB fibers. Mitochondrial enzymes; citrate kinase, 3-hydroxyacyl CoA dehydrogenase, and cytochrome c-oxidase were increased in the normoxic trained subjects (P <0.05). In summary, training induced adaptive responses in maximal aerobic power, HR, SV, Q(c), [La], and muscle fiber type composition, independent of inspired PO(2). Intramuscular data suggested there may be some differences between hyperoxic and normoxic training and these were substantiated by mitochondrial enzyme and lactate findings. Our data would suggest that transport mechanisms may limit the ability to increase aerobic power.

Effects of sprint cycle training on human skeletal muscle.

Eleven men sprint trained two to three times per week for 6 wk to investigate possible exercise-induced slow-to-fast fiber type conversions. Six individuals served as controls. Both groups were tested at the beginning and end of the study to determine anaerobic performance and maximal oxygen consumption. In addition, pre- and postbiopsies were extracted from the vastus lateralis muscle and were analyzed for fiber type composition, cross-sectional area, and myosin heavy chain (MHC) content. No significant changes were found in anaerobic or aerobic performance variables for either group. Although a trend was found for a decrease in the percentage of type IIb fibers, high-intensity sprint cycle training caused no significant changes in the fiber type distribution or cross-sectional area. However, the training protocol did result in a significant decrease in MHC IIb with a concomitant increase in MHC IIa for the training men. These data appear to support previous investigations that have suggested exercise-induced adaptations within the fast fiber population (IIb-->IIa) after various types of training (endurance and strength).

Skeletal muscle adaptations during early phase of heavy-resistance training in men and women.

An 8-wk progressive resistance training program for the lower extremity was performed twice a week to investigate the time course for skeletal muscle adaptations in men and women. Maximal dynamic strength was tested biweekly. Muscle biopsies were extracted at the beginning and every 2 wk of the study from resistance-trained and from nontrained (control) subjects. The muscle samples were analyzed for fiber type composition, cross-sectional area, and myosin heavy chain content. In addition, fasting blood samples were measured for resting serum levels of testosterone, cortisol, and growth hormone. With the exception of the leg press for women (after 2 wk of training) and leg extension for men (after 6 wk of training), absolute and relative maximal dynamic strength was significantly increased after 4 wk of training for all three exercises (squat, leg press, and leg extension) in both sexes. Resistance training also caused a significant decrease in the percentage of type IIb fibers after 2 wk in women and 4 wk in men, an increase in the resting levels of serum testosterone after 4 wk in men, and a decrease in cortisol after 6 wk in men. No significant changes occurred over time for any of the other measured parameters for either sex. These data suggest that skeletal muscle adaptations that may contribute to strength gains of the lower extremity are similar for men and women during the early phase of resistance training and, with the exception of changes in the fast fiber type composition, that they occur gradually.

Energy metabolism and fuel utilization.

1) Total energy expenditure during marathon training and competition is among the highest reported for any endurance activity. 2) Although training intensity for the marathon may vary between 60-125% of maximal physical working capacity, elite runners must run consistently at about 80-90% of VO2max in order to achieve successful competitive performances. 3) Earlier studies demonstrated that carbohydrate was the preferential fuel for endurance exercise, but more recent studies have suggested a greater role for lipids than previously thought. Also, proteins may contribute as much as 5-10% of the total energy to a marathon performance. 4) The preponderance of Type I and IIA skeletal muscle fibers among marathon runners and their significantly improved storage capacity for intramuscular lipids and increased mitochondrial density may account for increased reliance on oxidation of fats.

Strength and skeletal muscle adaptations in heavy-resistance-trained women after detraining and retraining.

Six women who had participated in a previous 20-wk strength training study for the lower limb detrained for 30-32 wk and subsequently retrained for 6 wk. Seven untrained women also participated in the 6-wk "retraining" phase. In addition, four women from each group volunteered to continue training an additional 7 wk. The initial 20-wk training program caused an increase in maximal dynamic strength, hypertrophy of all three major fiber types, and a decrease in the percentage of type IIb fibers. Detraining had relatively little effect on fiber cross-sectional area but resulted in an increased percentage of type IIb fibers with a concomitant decrease in IIa fibers. Maximal dynamic strength decreased but not to pretraining levels. Retraining for 6 wk resulted in significant increases in the cross-sectional areas of both fast fiber types (IIa and IIab + IIb) compared with detraining values and a decrease in the percentage of type IIb fibers. The 7-wk extension accentuated these trends such that cross-sectional areas continued to increase (nonsignificant) and no IIb fibers could be found. Similar results were found for the nonpreviously trained women. These data suggest that rapid muscular adaptations occur as a result of strength training in previously trained as well as non-previously trained women. Some adaptations (fiber area and maximal dynamic strength) may be retained for long periods during detraining and may contribute to a rapid return to "competitive" form.

Serum creatine kinase activity and its changes after a muscle biopsy.

The significance of the absolute elevations of serum creatine kinase (CK) levels after intense exercise and injuries was studied by measuring CK activities from seven healthy active males during a 2-week period, with a muscle biopsy taken between the first and second week. Most of the subjects (three lifters and two runners) carried on their normal exercise activities, while two lifters stopped training during the 2 weeks. The weight of the biopsy, number of fibres, percentage of fibre types, and cross-sectional areas of the muscle fibres were measured. The CK levels of the non-active subjects and runners remained consistently low during the control week, whereas those of the lifters were usually 500% greater than those of the other two groups, and fluctuated with the intensity of their workouts. A muscle biopsy, having a mean weight of 71.3 mg and containing 1800 fibres, increased the CK values by approximately 100 units litre-1 (U l-1) in most of the subjects. One runner injured his right hamstring muscles 2 days prior to the biopsy, and his CK values rose from 50 to 4400 U l-1. The increases in CK after the biopsy were not related to fibre type, activity, weight of the biopsy, or number or size of fibres removed. These results indicate that: (1) CK values are consistently lower in normal subjects and runners than in lifters. (2) Weight training results in chronic elevations of CK. (3) Compared to a muscle biopsy, muscular injury dramatically increases CK levels. (4) Elevation of serum CK is observed as early as 1 h after an intense weight-lifting session.(ABSTRACT TRUNCATED AT 250 WORDS)

Muscle hypertrophy and fast fiber type conversions in heavy resistance-trained women.

Twenty-four women completed a 20-week heavy-resistance weight training program for the lower extremity. Workouts were twice a week and consisted of warm-up exercises followed by three sets each of full squats, vertical leg presses, leg extensions, and leg curls. All exercises were performed to failure using 6-8 RM (repetition maximum). Weight training caused a significant increase in maximal isotonic strength (1 RM) for each exercise. After training, there was a decrease in body fat percentage (p less than 0.05), and an increase in lean body mass (p less than 0.05) with no overall change in thigh girth. Biopsies were obtained before and after training from the superficial portion of the vastus lateralis muscle. Sections were prepared for histological and histochemical examination. Six fiber types (I, IC, IIC, IIA, IIAB, and IIB) were distinguished following routine myofibrillar adenosine triphosphatase histochemistry. Areas were determined for fiber types I, IIA, and IIAB + IIB. The heavy-resistance training resulted in significant hypertrophy of all three groups: I (15%), IIA (45%), and IIAB + IIB (57%). These data are similar to those in men and suggest considerable hypertrophy of all major fiber types is also possible in women if exercise intensity and duration are sufficient. In addition, the training resulted in a significant decrease in the percentage of IIB with a concomitant increase in IIA fibers, suggesting that strength training may lead to fiber conversions.

Lipid depletion and repletion in skeletal muscle following a marathon.

Intramuscular lipid content was investigated in muscle biopsies from 10 well-trained endurance athletes before, immediately after, and 1, 3, 5, and 7 days after a marathon. Diets were controlled throughout the entire period of the study. Triglyceride content was ultrastructurally determined by the use of stereological methods. The volume percent lipid significantly decreased after the marathon and was lowest at 3 days post-marathon, rising slightly but still 35% lower than the pre-marathon value by 7 days post-marathon. Glycogen granules were abundant and tightly packed in the pre-marathon biopsies, scarce immediately post-marathon, and abundant, but less tightly packed, 7 days post-marathon. Post-marathon fluctuations in the volume percentages of mitochondria indicated possible fluid shifts within the muscle fibers: dehydration immediately post-marathon followed by rehydration with possible edema. Assuming the content of mitochondria remained constant throughout the recovery period, the ratio of the volume percentage of lipid to the volume percentage of mitochondria indicated that lipid content may have reached pre-marathon levels after 7 days post-marathon.

Effects of a Long-Term Fitness Program on Professional Baseball Players.

In brief: Players on a major league baseball team underwent physical fitness testing over a seven-year period (1981 to 1987). The purpose was to evaluate fitness status and design individualized conditioning programs for both the off-and in-seasons based on the test results. Body composition, flexibility, aerobic capacity, anaerobic power, and muscle strength and power were evaluated. Results indicated that baseball players are highly skilled athletes whose muscle strength and anaerobic power are excellent, whose flexibility is better than average, but whose aerobic capacity is low. A comprehensive conditioning and education program produced significant improvements. It also increased the players' awareness of the importance of a healthy life-style.

A comparison of energy expenditure during rowing and cycling ergometry.

Metabolic and cardiorespiratory responses of healthy adults were compared at similar incremental power outputs during a variable-resistance rowing exercise and a fixed-resistance cycle ergometer exercise. Repeated measurements of power (watts), VEBTPS, VO2 STPD, and HR were obtained on 60 men and 47 women ranging in age from 20 to 74 yr. Average maximal power output for the men was significantly higher (P less than 0.05) for cycling than rowing: 207 +/- 5.2 W vs 195 +/- 58 W (mean +/- SE). A similar difference was also observed for women favoring cycling: 135 +/- 4.1 W vs 126 +/- 4.9 W (mean +/- SE). VEBTPS, VO2 STPD, and HR were significantly higher at all power increments during the rowing graded exercise test (RGXT) when compared with the same exercise intensity during the cycle graded exercise test (CGXT). Consistent linearity was found between VEBTPS and VO2 STPD and between HR and VO2 STPD for both exercises. The linear relationship between VEBTPS and VO2 STPD for men during RGXT was r = 0.976, P less than 0.001, slope = 44.6 +/- 1.03, and for women during RGXT it was r = 0.990, P less than 0.001, slope = 19.6 +/- 0.36. The relationship between HR and VO2 STPD for men during rowing was r = 0.989, P less than 0.001, slope = 29.1 +/- 0.76, and for women during rowing it was r = 0.971, P less than 0.001, slope = 35.7 +/- 0.89. The linear relationship between VEBTPS and VO2 STPD for men during CGXT was r = 0.991, P less than 0.001, slope = 31.1 +/- 0.98, and for women it was r = 0.959, P less than 0.991, slope = 29.6 +/- 0.87. The relationship between HR and VO2 STPD for men during CGXT was r = 0.997, P less than 0.001, slope = 28.1 +/- 0.83, and for women it was r = 0.990, R less than 0.001, slope = 35.9 +/- 0.96. Results indicated that energy costs for rowing ergometry was significantly higher than cycle ergometry at all comparative power outputs including maximum levels. It was concluded that rowing ergometry could be an effective alternative activity for physical fitness and exercise rehabilitation programs.

Effect of a 42.2-km footrace and subsequent rest or exercise on muscular strength and work capacity.

This study 1) quantitates the effect of a 42.2-km footrace (marathon) on leg extensor strength (maximal peak torque, MPT) and work capacity (WC, measured during a leg extensor fatigue test), and 2) describes the effect of either a rest or exercise regimen for 1 wk after the marathon on the recovery of MPT and WC. Ten trained male runners performed personal records in a marathon and were then randomly assigned to either a rest or exercise-recovery group. The rest group did not train, whereas the exercise group ran 20-45 min/day at their selected intensity of exercise [50-60% maximal O2 consumption (Vo2max)] during the recovery week. MPT was measured at 1.1, 3.2, and 5.3 rad X s-1. The total work generated during a 50-contraction active extension-passive flexion fatigue test conducted at 3.2 rad X s-1 was defined as WC. Reports of perceived soreness of the quadriceps were obtained before each strength-testing session. These measurements were obtained before the marathon and 15-20 min and 1, 3, 5, and 7 days postmarathon. A significant reduction in MPT and WC resulted and continued 1 day postmarathon. MPT of both groups improved through day 5 postmarathon at 1.1 and 3.2 rad X s-1. MPT of the rest group improved through day 7 postmarathon but remained less than premarathon MPT. Recovery of MPT was impaired in the exercise group through days 5-7 postmarathon after 40-45 min exercise at 60% Vo2max. WC was recovered 3 days postmarathon in the rest group but was still impaired 7 days postmarathon in the exercise group.(ABSTRACT TRUNCATED AT 250 WORDS)

Applied physiology of rowing.

Elite oarsmen and oarswomen possess large body dimensions and show outstanding aerobic and anaerobic qualities. Oarsmen have VO2max values of 6.1 +/- 0.6 L/min and have incurred O2 debts of between 10 and 20 litres. The caloric expenditure of rowing estimated from the O2 cost of a 6-minute rowing ergometer exercise was calculated at 36 kcal/min, one of the highest energy costs so far reported for any predominantly aerobic-type sport. Aerobic and anaerobic calculations show that 70 to 75% of the energy necessary to row the standard 2000m distance for men is derived from aerobiosis while the remaining 25 to 30% is anaerobic. Women achieve VO2max values of 4.1 +/- 0.4 L/min and slightly lower anaerobic values than men. The relative 60 to 65% energy contribution of aerobic metabolism and 35 to 40% for anaerobiosis is not surprising since women compete at 1000m. Rowers also exhibit excellent isokinetic leg strength and power when compared with other elite athletes and oarswomen produced higher relative leg strength values than men when lean body mass is considered. Muscle fibre type distributions in oarsmen resemble those of distance runners while women tend to have a slightly higher proportion of fast-twitch fibres. An average power output of 390 +/- 13.6W was produced by oarsmen for 6 minutes of simulated rowing while women were able to develop 300 +/- 18.4 for 3 minutes of the same activity. Mechanical efficiency for rowing was calculated at 20 +/- 0.9%. Oarsmen also achieve very high ventilation volumes being able to average above 200 L/min BTPS for 6 minutes of simulated rowing; women ventilate 170 L/min BTPS for 3 minutes of this exercise. Excellent VO2/VE and O2 pulse values demonstrate outstanding cardiorespiratory efficiency. Both oarsmen and oarswomen utilise a unique physiological pattern of race pacing; they begin exertion with a vigorous sprint which places excessive demands on anaerobic metabolism followed by a severely high aerobic steady-state and then an exhaustive sprint at the finish. Tolerance to excessive anaerobiosis is evident by very high lactates and O2 deficits measured during the first 2 minutes of exercise. Physiological profiles of successful international calibre rowing athletes have been established as a result of studies described in this review and the data have been used in a variety of ways to improve rowing performance.