Strength and Muscular Adaptations After 6 Weeks of Rest-Pause vs. Traditional Multiple-Sets Resistance Training in Trained Subjects.

Prestes, J, Tibana, RA, de Araujo Sousa, E, da Cunha Nascimento, D, de Oliveira Rocha, P, Camarço, NF, Frade de Sousa, NM, and Willardson, JM. Strength and muscular adaptations after 6 weeks of rest-pause vs. traditional multiple-sets resistance training in trained subjects. J Strength Cond Res 33(7S): S113-S121, 2019-The purpose of this study was to compare the longitudinal effects of 6 weeks of rest-pause vs. traditional multiple-set resistance training (RT) on muscle strength, hypertrophy, localized muscular endurance, and body composition in trained subjects. Eighteen trained subjects (mean ± SD; age = 30.2 ± 6.6 years; weight = 74.8 ± 17.2 kg; height = 171.4 ± 10.3 cm) were randomly assigned to either a traditional multiple-set group (n = 9; 7 men and 2 women; 3 sets of 6 repetitions with 80% of 1-repetition maximum (1RM) and 2-minute rest intervals between sets) or a rest-pause group (n = 9; 7 men and 2 women). The results showed no significant differences (p > 0.05) between groups in 1RM strength (rest-pause: 16 ± 11% for bench press, 25 ± 17% for leg press and 16 ± 10% for biceps curl vs. traditional multiple-set: 10 ± 21% for BP, 30 ± 20% for LP and 21 ± 20% for BC). In localized muscular endurance, the rest-pause group displayed significantly greater (p < 0.05) repetitions, only for the LP exercise (rest pause: 27 ± 8% vs. traditional multiple-set: 8 ± 2%). In muscle hypertrophy, the rest-pause group displayed significantly greater (p < 0.05) thickness, only for the thigh (rest-pause: 11 ± 14% vs. traditional multiple-set: 1 ± 7%). In conclusion, RT performed with the rest-pause method resulted in similar gains in muscle strength as traditional multiple-set training. However, the rest-pause method resulted in greater gains in localized muscular endurance and hypertrophy for the thigh musculature.

Corrigendum: Two Consecutive Days of Extreme Conditioning Program Training Affects Pro and Anti-inflammatory Cytokines and Osteoprotegerin without Impairments in Muscle Power.

[This corrects the article DOI: 10.3389/fphys.2016.00260.].

Critical load: a novel approach to determining a sustainable intensity during resistance exercise.

BACKGROUND: A hyperbolic function as well as a linear relationship between power output and time to exhaustion (Tlim) has been consistently observed during dynamic non-resistive exercises. However, little is known about its concept to resistance exercises (RE), which could be defined as critical load (CL). This study aimed to verify the existence of CL during dynamic RE and to verify the number of workbouts necessary to determine the optimal modeling to achieve it. METHODS: Fifteen healthy men (23±2.5 yrs) completed 1 repetition maximum test (1RM) on a leg press and 3 (60%, 75% and 90% of 1RM) or 4 (+ 30% of 1RM) workbouts protocols to obtain the CL by hyperbolic and linear regression models between Tlim and load performed. Blood lactate and leg fatigue were also measured. RESULTS: CL was obtained during RE and 3 workbouts protocol estimate it at 53% while 4 tests at 38% of 1 RM. However, based on coefficients of determination, 3 protocols provided a better fit than the 4-parameter model, respectively (R2>0.95 vs. >0.77). Moreover, all intensities increased blood lactate and leg fatigue, however, when corrected by Tlim, were significantly lower at CL. CONCLUSIONS: It was possible to determinate CL during dynamic lower limbs RE and that 3 exhaustive workbouts can be used to better estimate the CL, constituting a new concept of determining this threshold during dynamic RE and reducing the physically demanding nature of the protocol. These findings may have important applications for functional performance evaluation and prescription of RE programs.

Two Consecutive Days of Crossfit Training Affects Pro and Anti-inflammatory Cytokines and Osteoprotegerin without Impairments in Muscle Power.

The aim of this study was to investigate the effects of two consecutive Crossfit® training sessions (24 h apart) designed to enhance work-capacity that involved both cardiovascular and muscular exercises on cytokines, muscle power, blood lactate and glucose. Nine male members of the CrossFit® community (age 26.7 ± 6.6 years; body mass 78.8 ± 13.2 kg; body fat 13.5 ± 6.2%; training experience 2.5 ± 1.2 years) completed two experimental protocols (24 h apart): (1) strength and power exercises, (2) gymnastic movements, and (3) metabolic conditioning as follows: 10 min of as many rounds as possible (AMRAP) of 30 double-unders and 15 power snatches (34 kg). The same sequence as repeated on session 2 with the following metabolic conditioning: 12 min AMRAP of: row 250 m and 25 target burpees. Serum interleukin-6 (IL-6), IL-10, and osteoprotegerin were measured before, immediately post and 24 h after workout of the day (WOD) 1, immediately post, 24 and 48 h after WOD 2. Peak and mean power were obtained for each repetition (back squat with 50% of 1 repetition maximum) using a linear position transducer measured before, immediately post and 24 h after WOD 1, immediately post and 24 h after WOD 2. Blood lactate and glucose were measured pre and immediately post WOD 1 and 2. Although both sessions of exercise elicited an significant increase in blood lactate (1.20 ± 0.41 to 11.84 ± 1.34 vs. 0.94 ± 0.34 to 9.05 ± 2.56 mmol/l) and glucose concentration (81.59 ± 10.27 to 114.99 ± 12.52 vs. 69.47 ± 6.97 to 89.95 ± 19.26 mg/dL), WOD 1 induced a significantly greater increase than WOD 2 (p ≤ 0.05). The training sessions elicited significant changes (p ≤ 0.05) in IL-6, IL-10 and osteoprotegerin concentration over time. IL-6 displayed an increase immediately after training WOD 1 [197 ± 109%] (p = 0.009) and 2 [99 ± 58%] (p = 0.045). IL-10 displayed an increase immediately after only WOD 1 [44 ± 52%] (p = 0.046), and decreased 24 and 48 h following WOD 2 (~40%; p = 0.018) as compared to pre-exercise values. Osteoprotegerin displayed a decrease 48 h following WOD 2 (~25%; p = 0.018) as compared with pre intervention. In conclusion, two consecutive Crossfit® training sessions increase pro/anti-inflammatory cytokines with no interference on muscle performance in the recovery period.

Different acute cardiovascular stress in response to resistance exercise leading to failure versus not to failure in elderly women with and without hypertension--a pilot study.

OBJECTIVE: The purpose of the present study was to compare the effects of resistance exercise (RE) leading to failure versus not to failure on 24-h blood pressure (BP) and rate-pressure product (RPP) responses in normotensive and hypertensive trained elderly women. METHODOLOGY: Seven normotensive women and seven women with medically documented hypertension randomly performed three experimental sessions: (i) a non-exercise control session that involved 30 min of seated rest, (ii) whole body RE leading to failure that involved three sets with an eight repetitions maximum (8RM) load and (iii) whole body RE not to failure that involved three sets with 70% of an 8RM load. Systolic BP (SBP), diastolic BP (DBP) and mean BP (MBP) responses during each hour of sleep and awake states were measured. RESULTS: Results of all subjects revealed that the RPP was higher (P ≤ 0.05) during afternoon and night hours after the RE session leading to failure versus not to failure and the non-exercise control session. For the hypertensive group during the night hours, SBP remained higher after the RE session not to failure (P = 0.047) versus non-exercise control session. For the normotensive group, DBP remained higher after the RE session leading to failure over the 24-h period (approximately 8 mmHg h(-1), P = 0.044) and the period upon awaking (approximately 5 mmHg h(-1), P = 0.044) versus the hypertensive group. CONCLUSIONS: The normotensive elderly women of this pilot study presented a greater cardiovascular response to RE leading to failure, as a consequence of the higher training intensity.

Similar hypotensive effects of combined aerobic and resistance exercise with 1 set versus 3 sets in women with metabolic syndrome.

The aim of the present study was to compare the response of systolic blood pressure (SBP), mean blood pressure (MBP) and diastolic blood pressure (DBP) following combined training with 1 set or with 3 sets of resistance exercise (RE). Sixteen women with metabolic syndrome (MetS) were randomly assigned to perform two combined exercise protocols and a control session (CON): 1-set, 30 min of aerobic exercise (AE) at 65-70% of reserve heart rate and 1 set of 8-12 repetitions at 80% of 10-RM in six resistance exercises; 3-sets, same protocol but with 3 sets; and CON, 30 min of seated rest. The SBP, MBP and DBP were measured before and every 15 min during 90 min following the experimental sessions. The SBP displayed a decrease (P ≤ 0.05) during the 90 min following the RE session with 1-set and 3-set, while MBP was decreased (P ≤ 0.05) up to 75 min after 1-set and up to 30 min after the 3-set exercise session compared with pre-intervention values. There was a decrease in DBP only for the greatest individual decrease following 1-set (-6.1 mmHg) and 3-set (-4.9 mmHg) combined exercise sessions, without differences between them. The rate-pressure product and heart rate remained significantly higher (P ≤ 0.05) 75 min and 90 min after the combined exercise session with 1- and 3-sets compared with the CON, respectively. In conclusion, a low-volume RE combined with AE resulted in similar decrease of SBP when compared with RE with 3-sets in women with MetS, which could be beneficial in situations of limited time.

Continuous blood pressure response at different intensities in leg press exercise.

BACKGROUND: Generally, the evaluation of the blood pressure response to resistance exercise has been limited to the evaluation of discontinuous casual blood pressure monitoring, often measured at the end of the exercise. DESIGN: To continuously evaluate the blood pressure response at different intensities of leg press exercise with the same duration and number of repetitions. METHODS: Seven normotensive healthy men performed an incremental test on the leg press machine at relative intensities of one repetition maximum (1RM). The blood pressure and heart rate were measured simultaneously to the incremental exercise by a photoplethysmographic method. RESULTS: The mean ± SD peak values of the heart rate, diastolic blood pressure (DBP) and systolic blood pressure (SBP) were obtained on 70% of 1RM and were 145 ± 20 bpm, 113.1 ± 15.4 mmHg, and 192.4 ± 20.0 mmHg, respectively. The SBP was characterized by a decrease followed by an increase during the sets of exercise. The decrease in the SBP was 12-22 mmHg and took approximately 25 seconds to reach the minimum value before the increase. It was observed for all participants in most of the intensities. The rate of increase in the SBP was not statistically different between the intensities. CONCLUSIONS: Both duration and intensity of exercise have an impact on the blood pressure response. Above 30% of 1RM, the SBP decreases in approximately 20 seconds and starts to increase until the end of the set of leg press exercise.