Acute and Long-Term Comparison of Fixed vs. Self-Selected Rest Interval Between Sets on Upper-Body Strength.

ABSTRACT: Simão, R, Polito, M, de Salles, BF, Marinho, DA, Garrido, ND, Santos Junior, ERT, and Willardson, JM. Acute and long-term comparison of fixed vs. self-selected rest interval between sets on upper-body strength. J Strength Cond Res 36(2): 540-544, 2022-The effects of different rest interval durations between sets has been widely studied, but only recently, the self-selected rest interval (SSRI) has been a matter of interest. However, previous studies comparing fixed and SSRI have investigated only acute responses. The purpose of this study was to analyze the acute and long-term effects of a fixed rest interval (FRI) vs. an SSRI between sets on upper-body performance and strength gains. Thirty-three trained men were randomly divided into 2 groups: FRI (75 seconds between sets), and SSRI. Both groups performed 3 sets with 75% of 1-repetition maximum until repetition failure in the chest press (CP), lat pull-down (LPD), shoulder press (SP), and seated row (SR) 3 times a week for 8 weeks. The results demonstrated that the SSRI allowed for significantly greater repetition performance vs. the FRI in the CP (26.1 ± 2.0 vs. 21.5 ± 1.8), LPD (30.1 ± 2.3 vs. 24.9 ± 1.9), SP (24.0 ± 2.8 vs. 17.4 ± 1.5), and SR (26.3 ± 1.6 vs. 22.0 ± 1.6). In addition, the following strength gains were observed: SSRI (CP: 6.8%, LPD: 8.0%, SP: 6.7%, SR: 7.8%) and FRI (CP: 7.4%, LPD: 6.7%, SP: 6.1%, SR: 7.0%) without significant differences between the groups. In conclusion, within an 8-week period, both protocols seem to be effective for strength gains, despite the higher training volume accomplished by the SSRI group. However, the FRI was 37% more time efficient.

Single-Joint Exercise Results in Higher Hypertrophy of Elbow Flexors Than Multijoint Exercise.

ABSTRACT: Mannarino, P, Matta, T, Lima, J, Simão, R, and Freitas de Salles, B. Single-Joint Exercise Results in Higher Hypertrophy of Elbow Flexors Than Multijoint Exercise. J Strength Cond Res 35(10): 2677-2681, 2021-Recent data suggest that single-joint exercises are unnecessary to maximize the resistance training (RT) results in novice to advanced individuals. However, the present literature is still inconsistent on this topic and controversy arises. The aim of this study was to compare the effects of the unilateral dumbbell row (DR) (multiple-joint) vs. unilateral biceps curl (BC) (single-joint) exercises on strength and elbow flexors muscle thickness (MT). Ten untrained men were assigned to an 8-week RT program for elbow flexors, one arm performing DR and the other performing BC in a within-subject design. After a familiarization, pretraining MT was measured using an ultrasound (US) technique, and strength was tested using 10 repetition maximum (10RM) tests. After pretesting, 8 weeks of RT (4-6 sets, 8-12 repetitions to concentric failure, 2 sessions per week) was performed. Post-testing was conducted in the same order as pretesting 48 and 72 hours after the last session. Single-joint BC exercise resulted in higher hypertrophy of elbow flexors (11.06%) than the DR (5.16%) multijoint exercise after 8 weeks of RT (p = 0.009). The 10RM improvement was higher for DR in DR-trained arm, whereas 10RM for BC was higher in BC-trained arm. The single-joint exercise resulted in higher hypertrophy of the elbow flexors than multijoint exercise after 8 weeks of RT, whereas strength improvements were greater in accordance with specificity of RT exercise. Therefore, in RT prescription for elbow flexors hypertrophy, single-joint exercises such as BC should be emphasized.

Mixed Session Periodization as a New Approach for Strength, Power, Functional Performance, and Body Composition Enhancement in Aging Adults.

Berzerra, ES, Orssatto, LBR, Moura, BM, Willardson, JM, Simão, R, and Moro, ARP. Mixed session periodization as a new approach for strength, power, functional performance, and body composition enhancement in aging adults. J Strength Cond Res 32(10): 2795-2806, 2018-The purpose of this study was to compare the effects of mixed session periodization (MSP) vs. traditional periodization (TP) on strength, power, functional performance, and body composition in aging adults. Forty-five healthy aging adults were randomly divided into 3 groups: MSP, TP, and Control. Subjects were tested before the intervention for baseline values (week 4) and then repeated testing during (week 7 and week 11), as well as after the intervention (week 15). Subjects were tested on the following performance measures: 5 repetition maximum (5RM) leg press and seated leg curl; 12RM cable chest press; countermovement jump (CMJ) and squat jump; up-and-down stairs; timed up and go (TUG); and body composition. All comparisons were analyzed through a mixed-model analysis with repeated measures (group × time) and with Bonferroni post hoc tests (p ≤ 0.05). After the intervention, no significant differences were observed between experimental groups; however, the MSP and TP groups demonstrated significantly greater values vs. the Control group in the 5RM leg press (p < 0.01), seated leg curl (p < 0.01), and 12RM cable chest press (p < 0.001). For CMJ performance, the MSP and TP groups significantly increased at week 7 (p < 0.001). The MSP and TP groups significantly improved functional task performance, including TUG (p < 0.001), upstairs (p < 0.01), and downstairs (p < 0.01) after training. Furthermore, body composition for the lower limbs significantly changed for the MSP and TP groups, with increased fat-free mass (p < 0.001) and decreased fat mass (p < 0.01) after training. In conclusion, the MSP and TP models used in this study were equally effective in developing strength, power, and functional performance while increasing fat-free mass and improving body fat percentage in aging adults. However, it should be considered that the MSP protocol did result in greater effect sizes in lower-limb strength, lower-limb fat-free mass, up-and-down stair, and TUG performance.

Repetition Performance and Blood Lactate Responses Adopting Different Recovery Periods Between Training Sessions in Trained Men.

Miranda, H, Maia, MF, Paz, GA, de Souza, JAAA, Simão, R, Farias, DA, and Willardson, JM. Repetition performance and blood lactate responses adopting different recovery periods between training sessions in trained men. J Strength Cond Res 32(12): 3340-3347, 2018-The purpose of this study was to examine the effect of different recovery periods (24, 48, and 72 hours) between repeated resistance training (RT) sessions for the upper-body muscles on repetition performance and blood lactate responses in trained men. Sixteen recreationally trained men (age: 26.1 ± 3.1 years; height: 179 ± 4.5 cm; body mass: 82.6 ± 4.0 kg, 4.5 ± 2.2 years of RT experience) participated in this study. Eight repetition maximum (8RM) loads were determined for the bench press (BP), 30° incline bench press (BP30), and 45° incline bench press (BP45) exercises. To assess the effects of different recovery periods between repeated training sessions, 3 protocols were performed in randomized order, including 24 hours (P24), 48 hours (P48), and 72 hours (P72). Each RT session consisted of performing 4 repetition maximum sets of the BP, BP30, and BP45 with 8RM loads and 2-minute rest intervals between sets. Blood lactate levels were measured presession (PRE), immediately postsession (POST), 3 minutes postsession (P3), and 5 minutes postsession (P5). For the P24 protocol, significant decreases in repetition performance were found between sessions for the BP, BP30, and BP45 exercises, respectively. When considering session 2 only, the total work (repetition × sets) was significantly higher under P48 and P72 compared with P24 for the BP30 and BP45 exercises. Blood lactate levels (i.e., POST, P3, and P5) significantly increased for session 2 under the P24 compared with the P48 and P72 protocols, respectively. Therefore, coaches and practitioners who need to accomplish a higher training volume for the upper-body muscles should adopt recovery periods longer than 24 hours between sessions that train the same or similar muscle groups.

Influence of a Personal Trainer on Self-selected Loading During Resistance Exercise.

Dias, MRC, Simao, RF, Saavedra, FJF, and Ratamess, NA. Influence of a personal trainer on self-selected loading during resistance exercise. J Strength Cond Res 31(7): 1925-1930, 2017-The purpose of this study was to compare differences in muscle strength and self-selected resistance training intensities between trained subjects who trained under the supervision of a personal trainer (PT) and those who trained without supervision (WoPT). Twenty-one trained subjects, men (n = 12) and women (n = 9), completed 3 sessions (separated by 48 hours) in the following sequence: first session, self-selected intensity assessment consisting of performance of 3 sets of 10 repetitions for the leg press (LP), bench press (BP), leg extension (LE), and arm curl (AC) exercises with self-selected load; second session, a 1 repetition maximum (1RM) test to determine subjects' maximal strength in the 4 exercises; and third session, a 10RM test to determine the maximum load completed for 10 repetitions for each exercise. Self-selected training loads were significantly higher in PT compared with WoPT for the LP (by 15.6%), BP (by 26.6%), LE (by 12.1%), and AC (by 22.2%) exercises. Self-selected training loads expressed relative to 1RM and 10RM data were significantly higher in PT (49-59.5% of 1RM; 62.7-77.3% of 10RM) than WoPT (41-58.7% of 1RM; 58.7-76.2% of 10RM) with largest difference observed in the lower-body exercises. Ratings of perceived exertion values were significantly higher in PT compared with WoPT. The results of the present study indicated that supervised resistance training with a personal trainer was advantageous in trained subjects although self-selected loading was still considerably lower than 1RM and 10RM percentage values.

Ischemic Preconditioning and Placebo Intervention Improves Resistance Exercise Performance.

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.

Long Rest Interval Promotes Durable Testosterone Responses in High-Intensity Bench Press.

The purpose of this study was to examine the influence of rest period duration (1 vs. 3 minute between sets) on acute hormone responses to a high-intensity and equal volume bench press workout. Ten resistance-trained men (25.2 ± 5.6 years; 78.2 ± 5.7 kg; 176.7 ± 5.4 cm; bench press relative strength: 1.3 ± 0.1 kg per kilogram of body mass) performed 2 bench press workouts separated by 1 week. Each workout consisted of 5 sets of 3 repetitions performed at 85% of 1 repetition maximum, with either 1- or 3-minute rest between sets. Circulating concentrations of total testosterone (TT), free testosterone (FT), cortisol (C), testosterone/cortisol ratio (TT/C), and growth hormone (GH) were measured at preworkout (PRE), and immediately (T0), 15 minutes (T15), and 30 minutes (T30) postworkout. Rating of perceived exertion was recorded before and after each set. For TT, both rest lengths enhanced all postexercise verifications (T0, T15, and T30) compared with PRE, with 1 minute showing decreases on T15 and T30 compared with T0. For FT, both 1- and 3-minute rest protocols triggered augmentations on distinct postexercise moments (T0 and T15 for 1 minute; T15 and T30 for 3-minute) compared with PRE. The C values did not change throughout any postexercise verification for either rests. The TT/C ratio was significantly elevated for both rests in all postexercise moments compared with PRE. Finally, GH values did not change for both rest lengths. In conclusion, although both short and long rest periods enhanced acute testosterone values, the longer rest promoted a long-lasting elevation for both TT and FT.

Effect of Different Interset Rest Intervals on Performance of Single and Multijoint Exercises With Near-Maximal Loads.

The aim of this study was to investigate the acute effects of different interset rest intervals on performance of single- and multijoint exercises with near-maximal loads. Fifteen trained men (26.40 ± 4.94 years, 79.00 ± 7.10 kg, 176.6 ± 6.06 cm, 11.80 ± 2.47% body fat, and bench press relative strength: 1.26 ± 0.19 kg·kg of body mass) performed eight sessions (2 exercises × 4 interset rest intervals); each consisting of 5 sets with a 3RM load. The exercises tested were the machine chest fly (MCF) for the single-joint exercise and the barbell bench press (BP) for the multi-joint exercise with 1, 2, 3, and 5 minutes of rest between sets. The results indicated that for the MCF, significantly higher total number of repetitions were completed for the 2- (12.60 ± 2.35 reps; p = 0.027), 3- (13.66 ± 1.84 reps; p = 0.001), and 5-minute (12.93 ± 2.25 reps; p = 0.001) vs. the 1-minute (10.33 ± 2.60 reps) protocol. For the BP, a significantly higher total number of repetitions were completed for 3- (11.66 ± 2.79 reps; p = 0.002) and 5-minute (12.93 ± 2.25 reps; p = 0.001) vs. the 1-minute protocol (7.60 ± 3.52 reps). In addition, subjects completed significantly higher total number of repetitions for the 5-minute (12.93 ± 2.25 reps; p = 0.016) vs. 2-minute (9.53 ± 3.11 reps) protocol. Both exercises presented similar and progressive reductions in repetition performance for all rest protocols along the 5 sets, starting as soon as the second set for the shorter 1-minute rest protocol. In conclusion, to maintain the best consistency in repetition performance, rest intervals of 2 minutes between sets are sufficient for the MCF and 3-5 minutes for the BP. Thus, it appears that longer acute recovery time is needed for a multijoint (core) exercise such as the BP vs. a single-joint (assistance) exercise such as the MCF.

Influence of Rest Interval Length Between Sets on Blood Pressure and Heart Rate Variability After a Strength Training Session Performed By Prehypertensive Men.

Figueiredo, T, Willardson, JM, Miranda, H, Bentes, CM, Machado Reis, V, Freitas de Salles, B, and Simão, R. Influence of rest interval length between sets on blood pressure and heart rate variability after a strength training session performed by prehypertensive men. J Strength Cond Res 30(7): 1813-1824, 2016-The purposes of this study were to compare the effects of 2 different rest interval lengths between sets and exercises during strength training (ST) on blood pressure (BP) and heart rate variability (HRV) in prehypertensive trained men, and to verify how HRV influences BP. Eleven volunteer subjects (age: 26.1 ± 3.6 years; body mass: 74.1 ± 7.9 kg; height: 172.1 ± 4.1 cm; % body fat: 18.3 ± 6.3; ST experience: 1.7 ± 0.8 years) participated in this study. After assessing one repetition maximum (1RM) loads for the free weight bench press, lat pull-down, shoulder press, biceps curl, triceps extension, leg press, leg extension, and leg curl exercises; subjects performed 2 sessions with different rest intervals between sets and exercises in random order and 72 hours apart. Each ST session consisted of performing 3 sets of eight to 10 repetitions at 70% of a 1RM for each exercise, with either 1-minute (sequence 1 [SEQ1]) or 2-minute (sequence 2 [SEQ2]) rest intervals between sets and exercises, respectively. Before and after each session, BP and HRV (low frequency band, high frequency [HF] band, and square root of the mean squared difference of successive RR-interval index) were tracked for 60 minutes. The results demonstrated a postexercise hypotensive response (PEH) after both rest interval conditions (p ≤ 0.05). Additionally, increases in cardiac stress were noted after SEQ1, with a greater withdrawal in parasympathetic activity vs. baseline as noted in the HF band at 1-, 10-, and 20-minute postexercise (p ≤ 0.05). These results indicate that both sequences provided an effective stimulus for a PEH. Therefore, strength and conditioning professionals may prescribe 1- or 2-minute rest between sets and exercises when the goal is to reduce BP after training sessions. However, resting 1 minute between sets and exercises was associated with greater cardiac stress, and so this may necessitate prescription of longer rest intervals between sets and exercises when working with individuals who have been diagnosed with cardiovascular dysfunction.

Dose-response of 1, 3, and 5 sets of resistance exercise on strength, local muscular endurance, and hypertrophy.

The study's purpose was to compare the response of performing 1, 3, and 5 sets on measures of performance and muscle hypertrophy. Forty-eight men, with no weight training experience, were randomly assigned to one of the 3 training groups, 1 SET, 3 SETS, 5 SETS, or control group. All training groups performed 3 resistance training sessions per week for 6 months. The 5 repetition maximum (RM) for all training groups increased in the bench press (BP), front lat pull down (LPD), shoulder press (SP), and leg press (LP) (p ≤ 0.05), with the 5 RM increases in the BP and LPD being significantly greater for 5 SETS compared with the other training groups (p ≤ 0.05). Bench press 20 RM in the 3-SET and 5-SET groups significantly increased with the increase being significantly greater than the 1-SET group and the 5-SET group increase being significantly greater than the 3-SET group (p ≤ 0.05). LP 20 RM increased in all training groups (p ≤ 0.05), with the 5-SETS group showing a significantly greater increase than the 1-SET group (p ≤ 0.05). The 3-SET and 5-SET groups significantly increased elbow flexor muscle thickness (MT) with the 5-SET increase being significantly greater than the other 2 training groups (p ≤ 0.05). The 5-SET group significantly increased elbow extensor MT with the increase being significantly greater than the other training groups (p ≤ 0.05). All training groups decreased percent body fat, increased fat-free mass, and vertical jump ability (p ≤ 0.05), with no differences between groups. The results demonstrate a dose-response for the number of sets per exercise and a superiority of multiple sets compared with a single set per exercise for strength gains, muscle endurance, and upper arm muscle hypertrophy.

Influence of strength and flexibility training, combined or isolated, on strength and flexibility gains.

The aim of this study was to analyze the strength and flexibility gains after 12 weeks of strength and flexibility training (FLEX), isolated or combined. Twenty-eight trained women (age = 46 ± 6.52 years; body mass = 56.8 ± 5.02 kg; height = 162 ± 5.58 cm; mean ± SD) were randomly divided into 4 groups: strength training (ST) (n = 7), FLEX (n = 7), combination of strength and flexibility (ST + FLEX) (n = 7), and combination of flexibility and strength (FLEX + ST) (n = 7). All groups were assessed before and after training for the sit and reach test, goniometry, and 10 repetition maximum in bench press (BP) and leg press (LP) exercises. The training protocol for all groups included training sessions on alternate days and was composed of 8 exercises performed at periodized intensities. The FLEX consisted of dynamic stretching performed for a total duration of 60 minutes. The results demonstrated significant strength gains in all groups in the LP exercise (FLEX: p = 0.0187; ST: p = 0.0001; FLEX + ST: p = 0.0034; ST + FLEX: p = 0.0021). All groups except the FLEX improved in BP strength (FLEX: p = 0.1757; ST: p = 0.0001; FLEX + ST: p = 0.0017; ST + FLEX: p = 0.0035). Statistical analyses did not show significant differences between groups; however, effect sizes demonstrated slightly different treatment effects for each group. Largest treatment effects were calculated for the ST group (LP: 2.72; BP: 1.25) and the lowest effects in the FLEX group (LP: 0.41; BP: -0.06). Both combination groups demonstrated lower effect sizes for both LP and BP as compared with the ST group. No significant differences in flexibility were seen in any group, in any of the comparisons (p > 0.05). In conclusion, these findings suggest that combining strength and FLEX is not detrimental to flexibility development; however, combined training may slightly reduce strength development, with little influence of order in which these exercises are performed.

The Effect of Rest Interval Length on Repetition Consistency and Perceived Exertion During Near Maximal Loaded Bench Press Sets.

The purpose of this study was to compare different rest intervals between sets on repetition consistency and ratings of perceived exertion (RPE) during consecutive bench press sets with an absolute 3RM (3 repetition maximum) load. Sixteen trained men (23.75 ± 4.21 years; 74.63 ± 5.36 kg; 175 ± 4.64 cm; bench press relative strength: 1.44 ± 0.19 kg/kg of body mass) attended 4 randomly ordered sessions during which 5 consecutive sets of the bench press were performed with an absolute 3RM load and 1, 2, 3, or 5 minutes of rest interval between sets. The results indicated that significantly greater bench press repetitions were completed with 2, 3, and 5 minutes vs. 1-minute rest between sets (p ≤ 0.05); no significant differences were noted between the 2, 3, and 5 minutes rest conditions. For the 1-minute rest condition, performance reductions (relative to the first set) were observed commencing with the second set; whereas for the other conditions (2, 3, and 5 minutes rest), performance reductions were not evident until the third and fourth sets. The RPE values before each of the successive sets were significantly greater, commencing with the second set for the 1-minute vs. the 3 and 5 minutes rest conditions. Significant increases were also evident in RPE immediately after each set between the 1 and 5 minutes rest conditions from the second through fifth sets. These findings indicate that when utilizing an absolute 3RM load for the bench press, practitioners may prescribe a time-efficient minimum of 2 minutes rest between sets without significant impairments in repetition performance. However, lower perceived exertion levels may necessitate prescription of a minimum of 3 minutes rest between sets.

Influence of Load Intensity on Postexercise Hypotension and Heart Rate Variability after a Strength Training Session.

The purpose of this study was to compare blood pressure and heart rate variability (HRV) responses in trained men after strength training (ST) sessions with loads of 60, 70, and 80% of a 1 repetition maximum (1RM). Eleven men (age: 26.1 ± 3.6 years; body mass: 74.1 ± 8.1 kg; height: 172.0 ± 4.0 cm; body mass index: 25.0 ± 1.96 kg·m(-2); %G: 18.3 ± 6.4) with at least 6-month ST experience participated in this study. After assessment of 1RM loads for the bench press (BP), lat pull-down (LPD), shoulder press (SP), biceps curl (BC), triceps extension (TE), leg press (LP), leg extension (LE), and leg curl (LC), subjects performed 3 experimental sessions in random order. During each experimental session, subjects performed 3 sets of 8-10 repetitions at 60, 70, or 80% of 1RM loads, with 2-minute rest intervals between sets and exercises. All experimental sessions were performed in the following exercise order: BP, LPD, SP, BC, TE, LP, LE, and LC. Before and for 1 hour after each experimental session, blood pressure and HRV were tracked. The results demonstrated a greater duration of postexercise hypotension (PEH) after the 70% of 1RM session vs. the 60 or 80% of 1RM session. These results indicate that the load/volume associated with completion of 8-10 repetitions at 70% of 1RM load may provide the best stimulus for the PEH response when compared with training with a 60 or 80% of 1RM loads. In conclusion, strength and conditioning professionals may prescribe exercises with 60, 70, and 80% of 1RM loads if the intent is to elicit an acute decrease in blood pressure after an ST session; however, 70% of 1RM provides a longer PEH.

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

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.

Influence of number of sets on blood pressure and heart rate variability after a strength training session.

The purpose of this study was to compare the acute effects of 1, 3, and 5 sets of strength training (ST), on heart rate variability (HRV) and blood pressure. Eleven male volunteers (age: 26.1 ± 3.6 years; body mass: 74.1 ± 8.1 kg; height: 172 ± 4 cm) with at least 6 months previous experience in ST participated in the study. After determining the 1 repetition maximum (1RM) load for the bench press (BP), lat pull down (LPD), shoulder press (SP), biceps curl (BC), triceps extension (TE), leg press (LP), leg extension (LE), and leg curl (LC), the participants performed 3 different exercise sequences in a random order and 72 hours apart. During the first sequence, subjects performed a single set of 8-10 repetitions, at 70% 1RM, and with 2-minute rest interval between exercises. Exercises were performed in the following order: BP, LPD, SP, BC, TE, LP, LE, and LC. During the second sequence, subjects performed the same exercise sequence, with the same intensity, 2-minute rest interval between sets and exercises, but with 3 consecutive sets of each exercise. During the third sequence, the same protocol was followed but with 5 sets of each exercise. Before and after the training sessions, blood pressure and HRV were measured. The statistical analysis demonstrated a greater duration of postexercise hypotension after the 5-set program vs. the 1 set or 3 sets (p ≤ 0.05). However, the 5-set program promoted a substantial cardiac stress, as demonstrated by HRV (p ≤ 0.05). These results indicate that 5 sets of 8-10 repetitions at 70% 1RM load may provide the ideal stimulus for a postexercise hypotensive response. Therefore, ST composed of upper- and lower-body exercises and performed with high volumes are capable of producing significant and extended postexercise hypotensive response. In conclusion, strength and conditioning professionals can prescribe 5 sets per exercises if the goal is to reduce blood pressure after training. In addition, these findings may have importance, specifically in the early phase of high blood pressure development, but more research is needed in hypertensive populations to validate this hypothesis.

Acute effects of different intensities of resistance training on glycemic fluctuations in patients with type 1 diabetes mellitus.

Six men and six women (24.4 ± 6.4 years) who had been diagnosed with T1D for 7.3 ± 6.8 years volunteered for the study. Three RT sessions were repeated with the same experimental approach with randomized load percentages. Blood glucose measurements were performed at rest, after warm-up, immediately after the last set of each exercise, and 10, 20, and 30 minutes after the exercise session. Significant decreases from rest for blood glucose concentration in each intensity vs. post warm-up, immediately post exercise session, and 10, 20 and 30 minutes after total training session were observed. Effect size (ES) results for the 60 and 80% of 1RM intensities demonstrated large magnitudes. The three intensities investigated promoted a reduction in blood glucose levels and therefore can be recommended for diabetic patients. In addition, the moderate and high intensities appear to lower blood glucose levels to a greater extent than the low intensity.

Effects of Resistance Training Techniques on Metabolic Responses in Trained Males.

This study investigated the effects of biset, drop-set and traditional resistance training (RT) techniques on metabolic responses in resistance-trained males. Fifteen trained males (age 29.7 ± 6.1 years; body mass 83.4 ± 7.6 kg; RT experience 11.4 ± 6.7 years; one-repetition maximum (1RM) barbell bench press: body mass ratio 1.4 ± 0.1 a.u.) were assigned to three experimental conditions, in a randomized crossover design. The experimental conditions were bi-set (3×10 repetitions at 70%1RM in barbell bench press followed by 10 repetitions at 60%1RM in incline bench press), drop-set (3×10 repetitions at 70%1RM followed by 10 repetitions at 50%1RM in barbell bench press) and traditional RT (3×20 at 60%1RM in barbell bench press). A portable gas analyzer was used to assess energy expenditure and maximal oxygen uptake during the experimental protocols. Blood lactate levels were assessed at baseline and 1, 3, and 5 minutes after the training session. There were no differences for total training volume (p = 0.999). Post hoc comparisons revealed that bi-set elicited higher aerobic energy expenditure (p = 0.003 vs. drop-set; p < 0.001 vs. traditional RT) and aerobic oxygen consumption (p = 0.034 vs. drop-set; p < 0.001 vs. traditional RT) than other RT schemes. There were no differences regarding anaerobic EE between-conditions (p > 0.05). There was a main effect of time and condition for blood lactate levels (p < 0.001). Post hoc comparisons revealed that drop-set training elicited higher blood lactate levels than traditional RT (p = 0.009). The results suggest that RT techniques may have a potential role in optimizing metabolic responses in resistance-trained males.

Supra-physiological doses of testosterone affect membrane oxidation of human neutrophils monitored by the fluorescent probe C11-BODIPY58¹/59¹.

The purpose of this study was to determine the effects of supra-physiological doses of testosterone (TES) on membrane oxidation of activated human neutrophils in vitro using an innovative and sensitive technique: the real-time detection with the fluorescence probe C11-BODIPY(581/591). Methodological controls were performed with the lipid-soluble and powerful antioxidant astaxanthin at different neutrophil density cultures. Neutrophils from nine healthy young men (23.4 ± 2.5 years, 174.4 ± 7.0 cm height, and 78.3 ± 7.0 kg weight) were isolated and treated with 0.1 or 10 µM TES for 24 h and subsequently labeled with the free radical-sensitive probe C11-BODIPY(581/591) for monitoring membrane oxidation after neutrophil activation with phorbol-12-myristate-13-acetate (PMA). First-order exponential decay kinetic indicated that both 0.1 and 10 µM TES severely increased baseline membrane oxidation in non-activated human neutrophils (compared to control). However, similar kinetics of membrane oxidation were observed in control and 0.1 µM TES-treated neutrophils after PMA activation, whereas chemical activation did not alter the baseline higher rates of membrane oxidation in 10 µM TES-treated neutrophils. The data presented here support the hypothesis that TES exerts distinct effects on the membrane oxidation of human neutrophils, depending on its dose (here, 10(2) to 10(4)-fold higher than physiological levels in men) and on PMA activation of the oxidative burst. Furthermore, this paper also presents an innovative application of the free radical-sensitive probe C11-BODIPY(581/591) for monitoring (auto-induced) membrane oxidation as an important parameter of viability and, thus, responsiveness of immune cells in inflammatory processes.

Effects on strength, power, and flexibility in adolescents of nonperiodized vs. daily nonlinear periodized weight training.

The aim of this study was to compare 2 models of resistance training (RT) programs, nonperiodized (NP) training and daily nonlinear periodized (DNLP) training, on strength, power, and flexibility in untrained adolescents. Thirty-eight untrained male adolescents were randomly assigned to 1 of 3 groups: a control group, NP RT program, and DNLP program. The subjects were tested pretraining and after 4, 8, and 12 weeks for 1 repetition maximum (1RM) resistances in the bench press and 45° leg press, sit and reach test, countermovement vertical jump (CMVJ), and standing long jump (SLJ). Both training groups performed the same sequence of exercises 3 times a week for a total of 36 sessions. The NP RT consisted of 3 sets of 10-12RM throughout the training period. The DNLP training consisted of 3 sets using different training intensities for each of the 3 training sessions per week. The total volume of the training programs was not significantly different. Both the NP and DNLP groups exhibited a significant increase in the 1RM for the bench press and 45° leg press posttraining compared with that pretraining, but there were no significant differences between groups (p ≤ 0.05). The DNLP group's 1RM changes showed greater percentage improvements and effect sizes. Training intensity for the bench press and 45° leg press did not significantly change during the training. In the CMVJ and SLJ tests, NP and DNLP training showed no significant change. The DNLP group showed a significant increase in the sit and reach test after 8 and 12 weeks of training compared with pretraining; this did not occur with NP training. In summary, in untrained adolescents during a 12-week training period, a DNLP program can be used to elicit similar and possible superior maximal strength and flexibility gains compared with an NP multiset training model.

Influence of exercise order on repetition performance among all possible combinations on resistance training.

The purposes of this study were to compare the repetition performance and rating of perceived exertion (RPE) in different exercises order of three resistance training (RT) exercises: bench press (BP), shoulder press (SP), and triceps extension (TE). Twelve trained men participated in this study (26.75 ± 2.49 years; 177 ± 4.66 cm; 77.7 ± 6.20 kg; 12.61 ± 2.01% body fat; RT experience 3.58 ± 1.24 years). Data were collected in two phases: (1) 10 RM test for BP, SP, and TE and (2) performance of six RT sequences. The sequences were: SEQA (BP, SP, TE), SEQB (BP, TE, SP), SEQC (SP, BP, TE), SEQD (SP, TE, BP), SEQE (TE, BP, SP), and SEQF (TE, SP, BP). The repetition performance on SEQD was significantly smaller than SEQE and SEQF. No significant differences were found for repetition performance and RPE among other sequences. These data indicate that priority might be given to exercises performed in the beginning of the RT session.