Carlos Alexandre Vieira

Session rating of perceived exertion following resistance exercise with blood flow restriction.

Session ratings of perceived exertion (SRPE) provide a valid and reliable indicator of resistance exercise session intensity. However, there is a lack of studies on the effects of resistance exercise with blood flow restriction (BFR) on SRPE. Thus, the aim of this study is to compare the effects of resistance exercise at high intensity versus low intensity with BFR on internal training load measured by SRPE. Thirteen young (22·2 ± 3·8 years) resistance‐trained men (training experience 3·2 ± 2·4 years) participated in the study protocol. After determining one maximum repetition (1‐RM), the subjects were assigned to two groups in a counterbalanced design (i) high‐intensity exercise (HIE, performed one training session at 80% of 1‐RM) and (ii) low intensity with BFR (BFR, performed an exercise session at 50% of 1‐RM with BFR). During each session, subjects performed three sets of unilateral elbow flexion leading to concentric failure with a 1‐min rest interval between sets. A cuff around the arm, inflated at 110 mmHg, was used continuously for BFR. The SRPE was reported 30 min after the end of the session. The low intensity with BFR showed lower total work (197·13 ± 63·49 versus 300·92 ± 71·81 kg; P = 0·002) and higher SRPE (9 versus 6; P = 0·007) than high‐intensity resistance exercise. The present results indicate that BFR is an important factor to increase internal training load. Future studies should investigate the physiological stress imposed by different training methods rather than just quantify the external training load such as intensity or volume.

One session of partial-body cryotherapy (−110 °C) improves muscle damage recovery

To evaluate the effects of a single session of partial‐body cryotherapy (PBC) on muscle recovery, 26 young men performed a muscle‐damaging protocol that consisted of five sets of 20 drop jumps with 2‐min rest intervals between sets. After the exercise, the PBC group (n = 13) was exposed to 3 min of PBC at −110 °C, and the control group (n = 13) was exposed to 3 min at 21 °C. Anterior thigh muscle thickness, isometric peak torque, and muscle soreness of knee extensors were measured pre, post, 24, 48, 72, and 96 h following exercise. Peak torque did not return to baseline in control group (P < 0.05), whereas the PBC group recovered peak torques 96 h post exercise (P > 0.05). Peak torque was also higher after PBC at 72 and 96 h compared with control group (P < 0.05). Muscle thickness increased after 24 h in the control group (P < 0.05) and was significantly higher compared with the PBC group at 24 and 96 h (P < 0.05). Muscle soreness returned to baseline for the PBC group at 72 h compared with 96 h for controls. These results indicate that PBC after strenuous exercise may enhance recovery from muscle damage.

Does whole-body cryotherapy improve vertical jump recovery following a high-intensity exercise bout?

Whole-body cryotherapy (WBC) has been used as a recovery strategy following different sports activities. Thus, the aim of the study reported here was to examine the effect of WBC on vertical jump recovery following a high-intensity exercise (HIE) bout. Twelve trained men (mean ± standard deviation age = 23.9±5.9 years) were randomly exposed to two different conditions separated by 7 days: 1) WBC (3 minutes of WBC at −110°C immediately after the HIE) and 2) control (CON; no WBC after the HIE). The HIE consisted of six sets of ten repetitions of knee extensions at 60° · s−1 concentric and 180° · s−1 eccentric on an isokinetic dynamometer. The vertical jump test was used to evaluate the influence of HIE on lower extremity muscular performance. The vertical jump was performed on a force platform before HIE (T1) and 30 minutes after (T2) the WBC and CON conditions. As a result of HIE, jump height, muscle power, and maximal velocity (Vmax) had significant decreases between T1 and T2, however no significance was found between the WBC and CON conditions. The results indicate that one session of WBC had no effect on vertical jump following an HIE compared with a CON condition. WBC may not improve muscle-function (dependent on stretch-shortening cycle) recovery in very short periods (ie, 30 minutes) following HIE.

Effects of partial-body cryotherapy (− 110 °C) on muscle recovery between high-intensity exercise bouts.

The aim of this study was to evaluate the effects of a single partial-body cryotherapy bout between training sessions on strength recovery. 12 young men (23.9±5.9 years) were randomly exposed to 2 different conditions separated by 7 days: 1) Partial-body cryotherapy (subjects were exposed to 3 min of partial-body cryotherapy at - 110 °C between 2 high-intensity training sessions); 2) Control (subjects were not exposed to partial-body cryotherapy between 2 high-intensity training sessions). Subjects were exposed to partial-body cryotherapy after the first training session. The 2 knee extension high-intensity training sessions were separated by a 40-min rest interval. Knee extension training consisted of 6 sets of 10 repetitions at 60°.s(-1) for concentric actions and 6 sets of 10 at 180.s(-1) for eccentric actions. The decrease in eccentric peak torque and total work was significantly (p<0.05) less after partial-body cryotherapy (5.6 and 2%, respectively) when compared to control (16 and 11.6%, respectively). However, the decrease in concentric peak torque and total work was not different (p>0.05) between partial-body cryotherapy (9.4 and 6.5%, respectively) and control (7.5 and 5.2%, respectively). These results indicate that the use of partial-body cryotherapy between-training sessions can enhance eccentric muscle performance recovery.

Effects of rest interval on strength recovery in breast cancer survivors

The purpose of this study was to compare the acute effect of 2 different resting intervals (RI) between sets of isokinetic knee extension exercise on peak torque (PT) and total work (TW) in breast cancer survivors (BCS) and control group (CNT). 16 BCS (52±4 years) and 14 CNT (53±6 years) performed 3 sets of 10 unilateral isokinetic knee extension repetitions at 60°.s(- 1) on 2 separate days with 2 different RI between sets (1 and 2 min). There was a significant interaction between groups vs. exercise sets (p=0.03) and RI vs. exercise sets (p<0.001) for PT. PT was greater in CNT at 1(st) and 2(nd) sets compared to BCS group (CNT, 133.4±20.8 and BCS 107.6±19.9 Nm, p=0.012 and CNT, 118.9±19.6 and BCS, 97.1±15.9  Nm, p=0.045, respectively). The TW of the knee extensor was significant greater in CNT than BCS group for all 3 knee extension exercise sets. In conclusion, the present study suggests that Breast Cancer Survivors women may need a longer rest interval (longer than 2 min) to be able to fully recover during a 3 sets of isokinetic knee extension exercise training session.

Cancer-Related Fatigue and Muscle Quality in Hodgkin’s Lymphoma Survivors

The purpose of this study was to compare fatigue, strength, body composition, muscle thickness, and muscle quality between Hodgkin’s lymphoma survivors (HLS) and apparently healthy subjects matched by age, gender, and physical activity levels (CON). Twelve HLS (32.16 ± 8.06) and 36 CON (32.42 ± 7.64) were enrolled in the study. Fatigue was assessed using the 20-item Multidimensional Fatigue Inventory, muscle strength using an isokinetic dynamometer, body composition using dual-energy X-ray absorptiometry, and thickness and muscle quality using B-mode ultrasound. Differences between HLS and CON were analyzed using independent samples t tests. No significant differences were observed between groups for any demographic characteristics: age (P = .922), weight (P = .943), height (P = .511), body mass index (P = .796), fat mass (P = .688), fat-free mass (P = .520), and percent body fat (P = .446). No significant differences were observed for strength (peak torque; P = .552), relative peak torque (P = .200), muscle thickness (P > .05) and muscle quality (P > .05). However, self-perceived fatigue was significantly higher in HLS than in CON (P = .009). It appears that when HLS are matched by age and physical activity levels to CON, no significant difference in body composition, muscle thickness, muscle quality, or strength is observed. Self-perceived fatigue, as predicted, is higher in HLS, which may have implications and should be considered when prescribing exercise training to this cancer population.

Chronic Effects of Resistance Training in Breast Cancer Survivors

Objective. To analyse effects of resistance training (RT) in breast cancer survivors (BCS) and how protocols and acute variables were manipulated. Methods. Search was made at PubMed, Science Direct, and LILACS. All articles published between 2000 and 2016 were considered. Studies that met the following criteria were included: written in English, Spanish, or Portuguese; BCS who have undergone surgery, chemotherapy, and/or radiotherapy; additional RT only; analysis of muscle performance, body mass composition (BMC), psychosocial parameters, or blood biomarkers. Results. Ten studies were included. PEDro score ranged from 5 to 9. Rest interval and cadence were not reported. Two studies reported continuous training supervision. All reported improvements in muscle strength, most with low or moderate effect size (ES), but studies performed with high loads presented large ES. Five described no increased risk or exacerbation of lymphedema. Most studies that analysed BMC showed no relevant changes. Conclusions. RT has been shown to be safe for BCS, with no increased risk of lymphedema. The findings indicated that RT is efficient in increasing muscle strength; however, only one study observed significant changes in BMC. An exercise program should therefore consider the manipulation of acute and chronic variables of RT to obtain optimal results.

Can We Draw General Conclusions from Interval Training Studies

Interval training (IT) has been used for many decades with the purpose of increasing performance and promoting health benefits while demanding a relatively small amount of time. IT can be defined as intermittent periods of intense exercise separated by periods of recovery and has been divided into high-intensity interval training (HIIT), sprint interval training (SIT), and repeated sprint training (RST). IT use has resulted in the publication of many studies and many of them with conflicting results and positions. The aim of this article was to move forward and understand the studies’ protocols in order to draw accurate conclusions, as well as to avoid previous mistakes and effectively reproduce previous protocols. When analyzing the literature, we found many inconsistencies, such as the controversial concept of ‘supramaximal’ effort, a misunderstanding with regard to the term ‘high intensity,’ and the use of different strategies to control intensity. The adequate definition and interpretation of training intensity seems to be vital, since the results of IT are largely dependent on it. These observations are only a few examples of the complexity involved in IT prescription, and are discussed to illustrate some problems with the current literature regarding IT. Therefore, it is our opinion that it is not possible to draw general conclusions about IT without considering all variables used in IT prescription, such as exercise modality, intensity, effort and rest times, and participants’ characteristics. In order to help guide researchers and health professionals in their practices it is important that experimental studies report their methods in as much detail as possible and future reviews and meta-analyses should critically discuss the articles included in the light of their methods to avoid inappropriate generalizations.

Defining the number of bouts and oxygen uptake during the “Tabata protocol” performed at different intensities

It is usually reported that the Tabata protocol (TP) is performed with eight bouts of 20:10 intervals at a load equivalent to 170% of i V̇ O2max. However, the feasibility of accumulating 160 s of work at 170% i V̇ O2max has been questioned. This article tested the intensity that would allow the performance of the original TP on a cycle ergometer, and measured the highest value of oxygen consumption (V̇ O2) obtained during the TP and the time spent above 90% of the maximal oxygen uptake (V̇ O2max) during the TP performed at different intensities. Thirteen young active males (25.9 ± 5.5 years, 67.9 ± 9.2 kg, 1.70 ± 0.06 m, 23.6 ± 3.1 kg·m-2) participated in the study. Participants performed a graded exertion test (GXT) on a cycle ergometer to obtain maximum oxygen consumption (V̇ O2max) and the intensity associated with V̇ O2max (i V̇ O2max). V̇ O2, maximal heart rate (HRmax), and number of bouts performed were evaluated during the TP performed at 115%, 130%, and 170% of i V̇ O2max. V̇ O2max, HRmax, and iV̇ O2max were 51.8 ± 8.0 mL.kg-1·min-1, 186 ± 10 bpm, and 204 ± 26 W, respectively. The number of bouts performed at 115% (7 ± 1 bouts) was higher than at 130% (5 ± 1 bouts) and 170% (4 ± 1 bouts) (p < .0001). The highest V̇ O2 achieved at 115%, 130%, and 170% of iV̇ O2max was 54.2 ± 7.9 mL·kg-1·min-1, 52.5 ± 8.1 mL·kg-1·min-1, and 49.6 ± 7.5 mL·kg-1·min-1, respectively. Non significant difference was found between the highest V̇ O2 achieved at different intensities, however qualitative magnitude-inference indicate a likely small effect between 115% and 170% of iV̇ O2max. Time spent above 90% of the V̇ O2max during the TP at 115% (50 ± 48 s) was higher than 170% (23 ± 21 s; p < 0.044) with a probably small effect. In conclusion, our data suggest that the adequate intensity to perform a similar number of bouts in the original TP is lower than previously proposed, and equivalent to 115% of the iV̇ O2max. In addition, intensities between 115 and 130% of the iV̇ O2max should be used to raise the time spent above 90% V̇O2max.

Effects of Different Conditioning Activities on 100-m Dash Performance in High School Track and Field Athletes

This study compared the effects of different conditioning activities on the 100-m dash performance of 11 male, high school track and field athletes (mean age = 16.3; SD = 1.2 years). Participants performed a 100-m dash seven minutes after each of four randomized conditioning protocols, with each condition and 100-m dash separated by 3–10 days. The conditioning protocols were (a) control, no conditioning activity; (b) weighted plyometric, three sets of 10 repetitions of alternate leg bounding with additional load of 10% of the body mass; (c) free sprint, two 20-m sprints; and (d) resisted sprint (RS), two 20-m resisted sprints using an elastic tubing tool. We obtained session ratings of perceived exertion (SRPE) immediately after each conditioning protocol. There were no significant differences between any of the three experimental conditioning activities on 100-m sprint time, but the RS protocol improved 100-m sprint time compared with the control (no conditioning) protocol (p < .001). The RS also led to greater sprint velocity and higher SRPE compared with the control condition (p < .01). There was no significant association between SRPE and 100-m performance (p = .77, r = .05). These results suggest a benefit for young male track and field athletes to the elastic tubing warm-up activities prior to the 100-m dash.