ripheral blood concentrations of testosterone in males FLECK. Hormonal and growth factor responses to heavy resist-(9, 13, 19, 29). Furthermore, it has been suggested that ance exercise protocols. J. Appl, Physiol. 69(4): 1442-1450, training may influence resting values of testosterone (14-1990.-To examine endogenous anabolic hormone and growth training m a i lun ingivale t estosterone (14-factor responses to various heavy resistance exercise protocols 16). Limited data also indicate that human growth hor-(HREPs), nine male subjects performed each of six randomly mone may increase in response to an acute bout of assigned HREPs, which consisted of identically ordered exer-resistance exercise (25, 29, 33). VanHelder et al. (33) cises carefully designed to control for load [5 vs. 10 repetitions have demonstrated that human growth hormone elevamaximum (RM)], rest period length (1 vs. 3 min), and total tions may be dependent on specific exercise characteriswork effects. Serum human growth hormone (hGH), testoster-tics such as the load utilized and frequency of lifting one (T), somatomedin-C (SM-C), glucose, and whole blood exercise. To our knowledge, no data exist regarding solactate (HLa) concentrations were determined preexercise, matomedin-C responses to heavy resistance exercise promidexercise (i.e., after 4 of 8 exercises), and at 0, 5, 15, 30, 60, tocols. The purpose of this investigation was to deter-90, and 120 min postexercise. All HREPs produced significant mine the impact of load, rest period length, and total (P < 0.05) temporal increases in serum T concentrations, min te ima toftload, rest p rod th andmtota although the magnitude and time point of occurrence above work on serum testosterone, human growth hormone, resting values varied across HREPs. No differences were ob-and somatomedin-C response patterns during and after served for T when integrated areas under the curve (AUCs) different heavy resistance exercise protocols. were compared. Although not all HREPs produced increases in serum hGH, the highest responses were observed consequent METHODS to the H10/1 exercise protocol (high total work, 1 min rest, 10-RM load) for both temporal and time integrated (AUC) reNine healthy male subjects gave informed written consponses. The pattern of SM-C increases varied among HREPs sent to participate in this investigation. The physical and did not consistently follow hGH changes. Whereas tem-characteristics of the subjects were the following: age, poral changes were observed, no integrated time (A T "-) differ-24.66 ± 4.27 (SD) yr; height, 178.41 ± 7.77 cm; body ences between exercise protocols occurred. These data indicate that the release patterns (temporal or time integrated) observed mass, 81.08 l 12.03 kg; maximal oxygen consumption, are complex functions of the type of HREPs utilized and the 54.17 ±4.63 ml.kg-min-; and body fat 1596+4.18%. physiological mechanisms involved with determining periph-All subjects had recreational experience with resistance era] circulatory concentrations (e.g., clearance ...

To examine endogenous anabolic hormonal responses to two different types of heavy resistance exercise protocols (HREPs), eight male and eight female subjects performed two randomly assigned protocols (i.e. P-1 and P-2) on separate days. Each protocol consisted of eight identically ordered exercises carefully designed to control for load, rest period length, and total work (J) effects. P-1 utilized a 5 RM load, 3-min rest periods and had lower total work than P-2. P-2 utilized a 10 RM load, 1-min rest periods and had a higher total work than P-1. Whole blood lactate and serum glucose, human growth hormone (hGH), testosterone (T), and somatomedin-C [SM-C] (i.e. insulin-like growth factor 1, IGF-1) were determined pre-exercise, mid-exercise (i.e. after 4 of the 8 exercises), and at 0, 5, 15, 30, and 60 min post-exercise. Males demonstrated significant (p less than 0.05) increases above rest in serum T values, and all serum concentrations were greater than corresponding female values. Growth hormone increases in both males and females following the P-2 HREP were significantly greater at all time points than corresponding P-1 values. Females exhibited significantly higher pre-exercise hGH levels compared to males. The P-1 exercise protocol did not result in any hGH increases in females. SM-C demonstrated random significant increases above rest in both males and females in response to both HREPs.(ABSTRACT TRUNCATED AT 250 WORDS)

-androgens in some women (1, 9). For most women, exerDOs, EVERETT A. HARMAN, Louis J. MARCHrrELLi, SCOTT E. cise-induced increases in testosterone above resting con-GORDON, ROBERT MELLO, PETER N. FRYKMAN, L. PERRY Ko-centrations have not been observed (14,22, 41), suggest-ZIRIS, AND N. TRAVIS TuipLr='r. Changes in hormonal concen-ing that other anabolic hormones (e.g., growth hormone trations after different heavy-resistance exercise protocols in andgrowth factors) may play greater roles in the anabowomen. J. Appl. Physiol. 75(2): 594-604, 1993.-Nine eumenorrheic women (age 24.11 t 4.28 yr) performed each of six ran-lic adaptational mechanisms related to muscle and condomly assigned heavy-resistance protocols (HREPs) on sepa-nective tissue growth with resistance training (2,16,19, rate days during the early follicular phase of the menstrual 22). The exact mechanisms involved in such tissue recycle. The HREPs consisted of two series [series I (strength, S) modeling remain to be elucidated, as do the neuroendoand zeries 2 (hypertrophy, H)l of three protocols, each using crine mechanisms that might help mediate such tissue 0 identically ordered exercises controlled for load 15 vs. 10 repeti-growth.tions maximum (RM)l, rest period length (1 vs. 3 min), and The stress of heavy-resistance exercise has been total work (J) within each three-protocol series. Blood measures were determined pre-, mid-(after 4 of 8 exercises), and shown to be an effective stimulus for both strength and postexercise (0, 5, 15, 30, 60, 90, 120 min and 24 and 48 h). In muscle fiber hypertrophy (3,16,17, 28, 34). Furthermore, series I, a significant (P < 0.05) reduction in growth hormone heavy-resistance stress is unique as an exercise modality (GH) was observed at 90 min postexercise for all three proto-in producing high levels of force through recruitment of a cols. In series 2, the 10-RM protocol with 1-min rest periods large percentage of the motor unit pool. It is possible that (H10/I) produced significant increases above rest in GH con-the acute physiological changes that occur in response to centra'ions at 0, 5, and 15 min postexercise, and the H10/1 and a given heavy-resistance exercise protocol may provide H5/1 protocols demonstrated significant reductions at 90 and some insights into the physiological mechanisms of long-120 min postexercise. Cortisol demonstrated significant increases in response to the S10/3 protocol at 0 min, to the HI0/1 term adaptations (18). A greater appreciation of the difprotocol at midexercise and at 0 and 5 min postexercise, and to ferences among heavy-resistance exercise protocols the Ht5/1 protocol at 5 and 15 min postexercise. No significant needs to be gained to allow more specific exercise stimuli 0 charnges were observed in total insulin-like growth factor I, to-to be created when long-term training studies are undertal I estosterone, urea, or creatinine for any of the HREPs. Sig-taken. Physiological differences among various heavynificant elevations in whole blood lactate and ammonia along resistance ...

caused by submaximal endurance exercise stress. Kjaer TRAvis TRiPLE'r. Effects of different heavy-resistance exercise et al. (22) showed that the depressive effect of epidural protocols on plasma (3-endorphin concentrations. J. Appl. Phys-blockade on O-EP concentrations was less pronounced iol. 74(1): [450][451][452][453][454][455][456][457][458][459] 1993.-To examine the changes of plasma 13-endorphin (3-EP) concentrations in response to various with maximal than with submaximal exercise. It was heavy-resistance exercise protocols, eight healthy male sub-suggested that with maximal exercise, aside from imjects randomly performed each of six heavy-resistance exercise pulses from the muscles, nervous impulses from the moprotocols, which consisted of identically ordered exercises care-tor centers in the brain are major determinants of neurofully designed to control for the repetition maximum (RM) re-endocrine secretion and enhanced activity in higher neusistance (5 vs. 10 RM), rest period length (1 vs. 3 min), and total roendocrine centers. Thus it appears that maximal work (joules). Plasma #-EP, ammonia, whole blood lactate and short-term exercise presents a neurophysiological exerserum cortisol, creatine kinase, urea, and creatinine were de-cise stress that is much different from that caused by termined preexercise, midexercise, immediately postexercise, c ise essutat ch dferen From tt aused)by and at various time points after the exercise session (5 min-48 submaximal endurance exercise. Farrell et al. (13) sugh), depending on the specific blood variable examined. Only the gested that when an organism is stressed, both the enhigh total work-exercise protocol 1 mrin rest, 10 RM load dorphin and the sympathetic nervous systems are acti-(H10/1)] demonstrated significant increases in plasma /-EP ,'ated, and one purpose of the endorphin activation may and serum cortisol at midexercise and 0, 5, and 15 min postex-be to modulate the amount of sympathoactivation. ercise. Increases in lactate were observed after all protocols,The intensity of the exercise has been demonstrated to but the largest increases were observed after the H10/1 proto-be a primary variable involved in the stimulatory influcol. Within the H10/1 protocol, lactate concentrations were ence on plasma #-EP concentrations with exercise (3, 15, correlated (r = 0.82, P < 0.05) with plasma f3-EP concentrations. Cortisol increases were significantly correlated (r = 0.84) 19, 20). Still, because of the inverse relationship between with 24-h peak creatine kinase values. The primary finding of exercise intensity and duration of exercise, it appeared this investigation was that O-EP responds differently to various that a certain duration of exercise would be needed to heavy-resistance exercise protocols. In heavy-resistance exer-stimulate a significant increase in plasma concentrations cise, it appears that the duration of the force production and of fl-EP in a single bout of high-intensity exercise. the length of the rest periods between sets are key exercise Kr...

Various physical demands are placed on soldiers, whose effectiveness and survivability depend on their combat-specific physical fitness. Because sport training programs involving weight-based training have proven effective, this study examined the value of such a program for short-term military training using combat-relevant tests. A male weight-based training (WBT) group (n = 15; mean +/- SD: 27.0 +/- 4.7 years, 173.8 +/- 5.8 cm, 80.9 +/- 12.7 kg) performed full-body weight-based training workouts, 3.2-km runs, interval training, agility training, and progressively loaded 8-km backpack hikes. A male Army Standardized Physical Training (SPT) group (n = 17; mean +/- SD: 29.0 +/- 4.6 years, 179.7 +/- 8.2 cm, 84.5 +/- 10.4 kg) followed the new Army Standardized Physical Training program of stretching, varied calisthenics, movement drills, sprint intervals, shuttle running, and distance runs. Both groups exercised for 1.5 hours a day, 5 days a week for 8 weeks. The following training-induced changes were statistically significant (P < 0.05) for both training groups: 3.2-km run or walk with 32-kg load (minutes), 24.5 +/- 3.2 to 21.0 +/- 2.8 (SPT) and 24.9 +/- 2.8 to 21.1 +/- 2.2 (WBT); 400-m run with 18-kg load (seconds), 94.5 +/- 14.2 to 84.4 +/- 11.9 (SPT) and 100.1 +/- 16.1 to 84.0 +/- 8.4 (WBT); obstacle course with 18-kg load (seconds), 73.3 +/- 10.1 to 61.6 +/- 7.7 (SPT) and 66.8 +/- 10.0 to 60.1 +/- 8.7 (WBT); 5 30-m sprints to prone (seconds), 63.5 +/- 4.8 to 59.8 +/- 4.1 (SPT) and 60.4 +/- 4.2 to 58.9 +/- 2.7 (WBT); and 80-kg casualty rescue from 50 m (seconds), 65.8 +/- 40.0 to 42.1 +/- 9.9 (SPT) and 57.6 +/- 22.0 to 44.2 +/- 8.8 (WBT). Of these tests, only the obstacle course showed significant difference in improvement between the two training groups. Thus, for short-term (i.e., 8-week) training of relatively untrained men, the Army's new Standardized Physical Training program and a weight-based training experimental program can produce similar, significant, and meaningful improvements in military physical performance. Further research would be needed to determine whether weight-based training provides an advantage over a longer training period.