Alex Souto Maior

Influence of exercise order on the number of repetitions performed and perceived exertion during resistance exercises.

This study examined the performance effects of exercise order during a resistance-training session composed of only upper-body exercises. The 10 repetition maxmimum of 14 men and 4 women with at least 6 months of previous weight-training experience was determined for 5 upper-body exercises. Each subject then completed 2 training sessions separated by 48 hours in a counterbalanced crossover design. One session began with exercises of the large-muscle group and progressed to exercises of the small-muscle group (sequence A), whereas the other session was performed with the opposite exercise sequence (sequence B). The exercise order for sequence A was free-weight bench press (BP), machine lat pull-down (LPD), seated machine shoulder press (SP), standing free-weight biceps curl (BC) with a straight bar, and seated machine triceps extension (TE). The exercise order for sequence B was TE, BC, SP, LPD, and BP. During both sequences, 3 sets of each exercise were performed to concentric failure, with 2-minute recovery intervals between sets and exercises. Performing exercises of both the large- and the small-muscle groups at the end of an exercise sequence resulted in significantly fewer repetitions in the 3 sets of an exercise. This decrease in the number of repetitions performed was especially apparent in the third set when an exercise was performed last in an exercise sequence.

Abnormal cardiac repolarization in anabolic androgenic steroid users carrying out submaximal exercise testing.

1. The aim of the present study was to investigate the cardiovascular effects of anabolic androgenic steroid (AAS) abuse by comparing the electrocardiographic parameters before and after submaximal exercise between AAS users and non‐AAS users.

Ischemic Preconditioning and Placebo Intervention Improves Resistance Exercise Performance

Abstract Marocolo, M, Willardson, JM, Marocolo, IC, da Mota, GR, Simão, R, and Maior, AS. Ischemic preconditioning and PLACEBO intervention improves resistance exercise performance. J Strength Cond Res 30(5): 1462–1469, 2016—This study evaluated the effect of ischemic preconditioning (IPC) on resistance exercise performance in the lower limbs. Thirteen men participated in a randomized crossover design that involved 3 separate sessions (IPC, PLACEBO, and control). A 12-repetition maximum (12RM) load for the leg extension exercise was assessed through test and retest sessions before the first experimental session. The IPC session consisted of 4 cycles of 5 minutes of occlusion at 220 mm Hg of pressure alternated with 5 minutes of reperfusion at 0 mm Hg for a total of 40 minutes. The PLACEBO session consisted of 4 cycles of 5 minutes of cuff administration at 20 mm Hg of pressure alternated with 5 minutes of pseudo-reperfusion at 0 mm Hg for a total of 40 minutes. The occlusion and reperfusion phases were conducted alternately between the thighs, with subjects remaining seated. No ischemic pressure was applied during the control (CON) session and subjects sat passively for 40 minutes. Eight minutes after IPC, PLACEBO, or CON, subjects performed 3 repetition maximum sets of the leg extension (2-minute rest between sets) with the predetermined 12RM load. Four minutes after the third set for each condition, blood lactate was assessed. The results showed that for the first set, the number of repetitions significantly increased for both the IPC (13.08 ± 2.11; p = 0.0036) and PLACEBO (13.15 ± 0.88; p = 0.0016) conditions, but not for the CON (11.88 ± 1.07; p > 0.99) condition. In addition, the IPC and PLACEBO conditions resulted insignificantly greater repetitions vs. the CON condition on the first set (p = 0.015; p = 0.007) and second set (p = 0.011; p = 0.019), but not on the third set (p = 0.68; p > 0.99). No difference (p = 0.465) was found in the fatigue index and lactate concentration between conditions. These results indicate that IPC and PLACEBO IPC may have small beneficial effects on repetition performance over a CON condition. Owing to potential for greater discomfort associated with the IPC condition, it is suggested that ischemic preconditioning might be practiced gradually to assess tolerance and potential enhancements to exercise performance.

Cardiac autonomic dysfunction in anabolic steroid users

This study aimed to evaluate if androgenic‐anabolic steroids (AAS) abuse may induce cardiac autonomic dysfunction in recreational trained subjects. Twenty‐two men were volunteered for the study. The AAS group (n = 11) utilized AAS at mean dosage of 410 ± 78.6 mg/week. All of them were submitted to submaximal exercise testing using an Astrand–Rhyming protocol. Electrocardiogram (ECG) and respired gas analysis were monitored at rest, during, and post‐effort. Mean values of VO2, VCO2, and VE were higher in AAS group only at rest. The heart rate variability variables were calculated from ECG using MATLAB‐based algorithms. At rest, AAS group showed lower values of the standard deviation of R‐R intervals, the proportion of adjacent R‐R intervals differing by more than 50 ms (pNN50), the root mean square of successive differences (RMSSD), and the total, the low‐frequency (LF) and the high‐frequency (HF) spectral power, as compared to Control group. After submaximal exercise testing, pNN50, RMSSD, and HF were lower, and the LF/HF ratio was higher in AAS group when compared to control group. Thus, the use of supraphysiological doses of AAS seems to induce dysfunction in tonic cardiac autonomic regulation in recreational trained subjects.

Analysis of Heart Rate Deflection Points to Predict the Anaerobic Threshold by a Computerized Method

Abstract Marques-Neto, SR, Maior, AS, Maranhão Neto, GA, and Santos, EL. Analysis of heart rate deflection points to predict the anaerobic threshold by a computerized method. J Strength Cond Res 26(7): 1967–1974, 2012—Many studies have used the heart rate deflection points (HRDPs) during incremental exercise tests, because of their strong correlation with the anaerobic threshold. The aim of this study was to evaluate the profile of the HRDPs identified by a computerized method and compare them with ventilatory and lactate thresholds. Twenty-four professional soccer players (age, 22 ± 5 years; body mass, 74 ± 7 kg; height 177 ± 7 cm) volunteered for the study. The subjects completed a Bruce-protocol incremental treadmill exercise test to volitional fatigue. Heart rate (HR) and alveolar gas exchange were recorded continuously at ≥1 Hz during exercise testing. Subsequently, the time course of the HR was fit by a computer algorithm, and a set of lines yielding the lowest pooled residual sum of squares was chosen as the best fit. This procedure defined 2 HRDPs (HRDP1 and HRDP2). The HR break points averaged 43.9 ± 5.9 and 89.7 ± 7.5% of the V[Combining Dot Above]O2peak. The HRDP1 showed a poor correlation with ventilatory threshold (VT; r = 0.50), but HRDP2 was highly correlated to the respiratory compensation (RC) point (r = 0.98). Neither HRDP1 nor HRDP2 was correlated with LT1 (at V[Combining Dot Above]O2 = 2.26 ± 0.72 L·min−1; r = 0.26) or LT2 (2.79 ± 0.59 L·min−1; r = 0.49), respectively. LT1 and LT2 also were not well correlated with VT (2.93 ± 0.68 L·min−1; r = 0.20) or RC (3.82 ± 0.60 L·min−1; r = 0.58), respectively. Although the HR deflection points were not correlated to LT, HRDP2 could be identified in all the subjects and was strongly correlated with RC, consistent with a relationship to cardiorespiratory fatigue and endurance performance.

Influence of upper-body exercise order on hormonal responses in trained men

The aim of this study was to examine acute hormonal responses after different sequences of an upper-body resistance-exercise session. Twenty men completed 2 sessions (3 sets; 70% 1-repetition maximum; 2 min passive rest between sets) of the same exercises in opposite sequences (larger to smaller vs. smaller to larger muscle-group exercises). Total testosterone (TT), free testosterone (FT), testosterone/cortisol (T/C) ratio, sex-hormone-binding globulin (SHBG), growth hormone (GH), and cortisol (C) concentrations were measured before and immediately after each sequence. The results indicate that the GH concentration increased after both sessions, but the increase was significantly greater (p < 0.05) after the sequence in which larger muscle-group exercises were performed prior to the smaller muscle-group exercises. No differences were observed between sessions for TT, FT, SHBG, C, or the T/C ratio at baseline or immediately after resistance exercise. These results indicate that performing larger muscle-group exercises first in an upper-body resistance-exercise session leads to a significantly greater GH response. This may have been due to the significantly greater exercise volume accomplished. In summary, the findings of this investigation support the common prescriptive recommendation to perform larger-muscle group exercises first during a resistance-exercise session.

Influence of Blood Flow Restriction During Low-Intensity Resistance Exercise on the Postexercise Hypotensive Response.

Abstract Maior, AS, Simão, R, Martins, MSR, Salles, BFd, and Willardson, JM. Influence of blood flow restriction during low-intensity resistance exercise on the postexercise hypotensive response. J Strength Cond Res 29(10): 2894–2899, 2015—Low-intensity resistance exercise (RE) combined with blood flow restriction (BFR) has been shown to promote similar increases in strength and hypertrophy as traditional high-intensity RE without BFR. However, the effect of BFR on the acute postexercise hypotensive response has received limited examination. Therefore, the purpose of this study was to compare high-intensity exercise (HIE) vs. low-intensity RE with BFR on the postexercise hypotensive response in normotensive young subjects. Fifteen men (age: 23.4 ± 3.4 years) performed the following 2 experimental protocols in randomized order: (a) 3 sets of biceps curls (BCs) at 80% of 1 repetition maximum (RM) and 120-second rest between sets (HIE protocol) and (b) 3 sets of BCs at 40% of 1RM with BFR and 60-second rest between sets. Analysis of systolic blood pressure (SBP) and diastolic blood pressure (DBP) was conducted for 60 minutes after both protocols. The values for SBP, DBP, and mean blood pressure (MBP) at baseline and postexercise were not significantly different between the HIE vs. the BFR protocol. However, within the BFR protocol, significant decreases (p ⩽ 0.05) in SBP occurred at 30 minutes (125.86 ± 9.33 mm Hg) and 40 minutes (125.53 ± 10.19 mm Hg) after exercise when compared with baseline (132.86 ± 9.12 mm Hg) and significant decreases in DBP and MBP occurred at 20 minutes, 30 minutes, and 40 minutes after exercise vs. baseline (p ⩽ 0.05). Therefore, we conclude that exercises engaging a relatively small amount of muscle mass, such as the BC (or other similar single joint exercises), might be performed at a lower intensity with BFR to promote a postexercise hypotensive response.

Acute cardiovascular response in anabolic androgenic steroid users performing maximal treadmill exercise testing

Maior, AS, Simão, R, Salles, BF, Alexander, JL, Rhea, M, and Nascimento, JHM. Acute cardiovascular response in anabolic androgenic steroid users performing maximal treadmill exercise testing. J Strength Cond Res 24(6): 1688-1695, 2010-The purpose of this study was to investigate the cardiovascular effects of anabolic androgenic steroid (AAS) use, specifically the hemodynamic response, during maximal treadmill exercise testing by comparing the exercise response between users of AAS (U-AAS) and non-AAS users (N-AAS). Twenty-four men (n = 12; 29 ± 3.4 years and n = 12; 29.5 ± 8.2 years for the U-AAS and N-AAS groups, respectively) with regular participation in both resistance (mean = 6 d·wk−1) and aerobic exercise (mean = 2 d·wk−1) volunteered for the study. Both groups of subjects completed a ramp-protocol maximal treadmill exercise test to volitional fatigue. Several hemodynamic and metabolic measures were obtained before, during, and after testing. The results demonstrate for the first time that chronic administration of high doses of AAS (355.4 ± 59.47 mg·wk−1) lead to hemodynamic and metabolic response impairment. In conclusion, the chronotropic significant incompetence in the current study was reflected by an exaggerated hemodynamic response to exercise. Furthermore, the findings suggest that nonusers of AAS showed increases in &OV0312;o2max when compared to the AAS group. Therefore, this study provides a contraindication to AAS use, especially in those at increased risk of cardiovascular events.

ACUTE RESPONSES OF RATE PRESSURE PRODUCT IN SETS OF RESISTANCE EXERCISE

Objective: To compare the acute responses of rate pressure product (RPP) between dynamic and isometric sets of resistance exercise (RE); compare the acute responses of RPP between upper and lower limbs in RE. Methods: Nineteen active men (22.7 ± 2.2 years) attended this study in a random crossover model. In the first day they performed hemodynamic measurements and one maximum repetition tests (1RM) in leg press (LGP) and bench press (BCP) exercises. In the second, third, fourth and fifth days they performed the following tests: LGP isometric, BCP isometric, LGP dynamic and BCP dynamic, respectively. Isometric protocols were conducted in 3 sets of 40 s (1 st set: 25% 1RM, 2 nd set: 50% 1RM, 3 rd set: 75% 1RM) and dynamic protocols in 3 sets of 10 repetitions (1 st set: 25% 1RM, 2 nd set: 50% 1RM, 3 th set: 75% 1RM). The RPP was obtained immediately after each set. Results: A comparison between protocols showed that RPP was higher (P < 0.05) in dynamic than in isometric protocol. A comparison between exercises showed that RPP was higher (P < 0.05) in LGP than BCP exercise. Conclusions: In similar relative intensities, the acute cardiac responses are influenced by the exercise protocol, since the RPP was higher in the dynamic condition. Furthermore, RPP seems to be related with recruited muscle mass, since that were observed higher values of RPP in exercises for lower limbs .

Association between knee-to-hip flexion ratio during single-leg vertical landings, and strength and range of motion in professional soccer players

Abstract The aim of this study was to test the correlation between knee-to-hip flexion ratio during a single leg landing task and hip and knee strength, and ankle range of motion. Twenty-four male participants from a professional soccer team performed a continuous single leg jump-landing test during 10s, while lower limb kinematics data were collected using a motion analysis system. After biomechanical testing, maximal isometric hip (abduction, extension, external rotation), knee extension and flexion strength were measured. Maximum ankle dorsiflexion range of motion was assessed statically using the weight bearing lunge test. Pearson correlation coefficients were calculated to determine the associations between the predictor variables (knee and hip strength, and ankle ROM) and the main outcome measure (knee-to-hip flexion ratio). Correlation between knee-to-hip flexion ratio and hip abductors strength was significant (r = −0.47; p = 0.019). No other significant correlations were observed among the variables (p > 0.05). These results demonstrated that a lower hip abductors strength in male soccer players was correlated with a high knee-to-hip flexion ratio during landing from a single leg jump, potentially increasing knee overload by decreasing energy absorption at the hip. The results provide a novel proposal for the functioning of hip muscles to control knee overload.