Comparison of muscle activity and tissue oxygenation during strength training protocols that differ by their organisation, rest interval between sets, and volume

Effect of a new resistance training method on the metaboreflex in cardiac rehabilitation patients: a randomized controlled trial

Patients with cardiac disease exhibit exaggerated sympathoexcitation, pressor, and ventilatory responses to muscle metaboreflex activation (MMA). However, the effects of cardiac rehabilitation (CR) and especially resistance training (RT) modalities on MMA are not well known. This study investigated how CR impacts MMA in such patients, specifically examining the effects of two different resistance training (RT) protocols following 12 weeks of CR. In addition to endurance exercises, 32 patients were randomized into either a 3/7 RT modality (comprising 5 sets of 3-7 repetitions) or a control (CTRL) modality (involving 3 sets of 9 repetitions), with distinct inter-set rest intervals (15 s for 3/7 and 60 s for CTRL). MMA, gauged by blood pressure (BP) and ventilatory (Ve) responses during a handgrip exercise at 40% effort and subsequent post-exercise circulatory occlusion, demonstrated CR's significant impact. Systolic BP, initially at + 28 ± 23% pre-CR, improved to + 11 ± 15% post-CR (P = .011 time effect; P = .131 group effect). Diastolic BP showed a similar trend, from + 27 ± 23% to + 13 ± 15% (P = .099 time effect; P = .087 group effect). Ve, initially at + 60 ± 39%, reduced to + 14 ± 19% post-CR (P < .001 time effect; P = .142 group effect). Critical parameters-maximal oxygen consumption, lean mass, hand grip, and quadriceps strength-exhibited parallel increases in both 3/7 and CTRL groups (P < .05 time effect; P > .3 group effect). Ultimately, CR demonstrated comparable improvements in MMA across both RT modalities, indicating its positive influence on cardiovascular responses and physical performance in individuals with cardiac conditions.

Effects of High-Intensity Interval Training Using the 3/7 Resistance Training Method on Metabolic Stress in People with Heart Failure and Coronary Artery Disease: A Randomized Cross-Over Study

The 3/7 resistance training (RT) method involves performing sets with increasing numbers of repetitions, and shorter rest periods than the 3x9 method. Therefore, it could induce more metabolic stress in people with heart failure with reduced ejection fraction (HFrEF) or coronary artery disease (CAD). This randomized cross-over study tested this hypothesis. Eleven individuals with HFrEF and thirteen with CAD performed high-intensity interval training (HIIT) for 30 min, followed by 3x9 or 3/7 RT according to group allocation. pH, HCO3-, lactate, and growth hormone were measured at baseline, after HIIT, and after RT. pH and HCO3- decreased, and lactate increased after both RT methods. In the CAD group, lactate increased more (6.99 ± 2.37 vs. 9.20 ± 3.57 mmol/L, p = 0.025), pH tended to decrease more (7.29 ± 0.06 vs. 7.33 ± 0.04, p = 0.060), and HCO3- decreased more (18.6 ± 3.1 vs. 21.1 ± 2.5 mmol/L, p = 0.004) after 3/7 than 3x9 RT. In the HFrEF group, lactate, pH, and HCO3- concentrations did not differ between RT methods (all p > 0.248). RT did not increase growth hormone in either patient group. In conclusion, the 3/7 RT method induced more metabolic stress than the 3x9 method in people with CAD but not HFrEF.

Hemodynamic Tolerance of New Resistance Training Methods in Patients With Heart Failure and Coronary Artery Disease: A RANDOMIZED CROSSOVER STUDY

PURPOSE

The purpose of this study was to determine and compare the effectiveness of three different resistance training (RT) methods for cardiac rehabilitation.

METHODS

Individuals with heart failure with reduced ejection fraction (HFrEF, n = 23) or coronary artery disease (CAD, n = 22) and healthy controls (CTRL, n = 29) participated in this randomized crossover trial of RT exercises at 70% of the one-maximal repetition on a leg extension machine. Peak heart rate (HR) and blood pressure (BP) were measured noninvasively. The three RT methods were five sets of increasing repetitions from three to seven (RISE), of decreasing repetitions from seven to three (DROP), and three sets of nine repetitions (USUAL). Interset rest intervals were 15 sec for RISE and DROP and 60 sec for USUAL.

RESULTS

Peak HR differed on average by <4 bpm between methods in the HFrEF and CAD groups ( P < .02). Rises in systolic BP (SBP) in the HFrEF group were comparable across methods. In the CAD group, mean SBP at peak exercise increased more in RISE and DROP than in USUAL ( P < .001), but the increase was ≤10 mm Hg. In the CTRL group, SBP was higher for DROP than for USUAL (152 ± 22 vs 144 ± 24 mm Hg, respectively; P < .01). Peak cardiac output and perceived exertion did not differ between methods.

CONCLUSIONS

The RISE, DROP, and USUAL RT methods induced a similar perception of effort and similar increases in peak HR and BP. The RISE and DROP methods appear more efficient as they allow a comparable training volume in a shorter time than the USUAL method.

Changes in Muscle Deoxygenation During Squat Exercise After 6-Week Resistance Training With Different Percentages of Velocity Loss

ABSTRACT

Costilla, M, Casals, C, Marín-Galindo, A, Sánchez-Sixto, A, Muñoz-López, A, Sañudo, B, Corral-Pérez, J, and Ponce-González, JG. Changes in muscle deoxygenation during squat exercise after 6-week resistance training with different percentages of velocity loss. J Strength Cond Res XX(X): 000-000, 2022-The present study compared, for the first time, the effects of 6 weeks of 20% (20VL) vs. 40% (40VL) velocity loss (VL) resistance training (RT) programs on muscle oxygen dynamics during the squat exercise. Twenty-three young men (21.4 ± 2.4 years) were randomly allocated into the 20VL group (n = 8), 40VL group (n = 7), or control group (CG; n = 8). The RT program consisted of 3 sets of Smith machine back squat exercise at 20VL or 40VL with a 3-minute rest between sets, twice per week for 6 weeks. Tissue oxygenation index (TOI) was measured using near-infrared spectroscopy in the vastus medialis and vastus lateralis during a squat test (8-repetition 1 m·s-1 load test), and the maximum (maxTOI) and minimum (minTOI) TOIs were measured during a 3-min recovery period. After the 6-week RT program, TOI increased significantly at the beginning of the test in both muscles (during the first 4 repetitions in the vastus lateralis and 5 repetitions in the vastus medialis) in the 20VL group (p < 0.05), with nonsignificant changes in the 40VL group and CG. The maxTOI was significantly increased in the vastus medialis (+3.76%) and vastus lateralis (+3.97%) after the training only in the 20VL group (p < 0.05). The minTOI in the vastus medialis reached during the test remained unchanged postintervention for both training groups, with the CG showing significantly higher values compared with the 20VL group (+14.1%; p < 0.05). In conclusion, depending on the VL reached during a squat RT program, different changes in muscle oxygen dynamics can be expected. Training at 20% of VL improves metabolic efficiency and the reoxygenation peak after the set.

Electrode Size and Placement for Surface EMG Bipolar Detection from the Brachioradialis Muscle: A Scoping Review

The brachioradialis muscle (BRD) is one of the main elbow flexors and is often assessed by surface electromyography (sEMG) in physiology, clinical, sports, ergonomics, and bioengineering applications. The reliability of the sEMG measurement strongly relies on the characteristics of the detection system used, because of possible crosstalk from the surrounding forearm muscles. We conducted a scoping review of the main databases to explore available guidelines of electrode placement on BRD and to map the electrode configurations used and authors’ awareness on the issues of crosstalk. One hundred and thirty-four studies were included in the review. The crosstalk was mentioned in 29 studies, although two studies only were specifically designed to assess it. One hundred and six studies (79%) did not even address the issue by generically placing the sensors above BRD, usually choosing large disposable ECG electrodes. The analysis of the literature highlights a general lack of awareness on the issues of crosstalk and the need for adequate training in the sEMG field. Three guidelines were found, whose recommendations have been compared and summarized to promote reliability in further studies. In particular, it is crucial to use miniaturized electrodes placed on a specific area over the muscle, especially when BRD activity is recorded for clinical applications.

Strength Training: In Search of Optimal Strategies to Maximize Neuromuscular Performance

Training with low-load exercise performed under blood flow restriction can augment muscle hypertrophy and maximal strength to a similar extent as the classical high-load strength training method. However, the blood flow restriction method elicits only minor neural adaptations. In an attempt to maximize training-related gains, we propose using other protocols that combine high voluntary activation, mechanical tension, and metabolic stress.

Exercise and Osteoarthritis

Osteoarthritis (OA) is a degenerative disease of the articular cartilage with subchondral bone lesions. Osteoarthritis etiologies are mainly related to age, obesity, strain, trauma, joint congenital anomalies, joint deformities, and other factors. Osteoarthritis seriously affects the quality of life; however, there is no effective way to cure osteoarthritis. Aerobic exercise refers to a dynamic rhythmic exercise involving the large muscle groups of the body with aerobic metabolism. More and more evidence shows that exercise has become a useful tool for the treatment of osteoarthritis. This chapter will discuss the role of exercise in the prevention and treatment of osteoarthritis.

Acute Effects of the New Method Sarcoplasma Stimulating Training Versus Traditional Resistance Training on Total Training Volume, Lactate and Muscle Thickness

Background: Trained subjects have difficulty in achieving continued results following years of training, and the manipulation of training variables through advanced resistance training (RT) methods is widely recommended to break through plateaus.

Objective: The purpose of the present study was to compare the acute effects of traditional RT (TRT) versus two types of sarcoplasma stimulating training (SST) methods on total training volume (TTV), lactate, and muscle thickness (MT).

Methods: Twelve trained males (20.75 ± 2.3 years; 1.76 ± 0.14 meters; body mass = 79.41 ± 4.6 kg; RT experience = 4.1 ± 1.8 years) completed three RT protocols in a randomly sequenced order: TRT, SST contraction type (SST-CT), or SST rest interval variable (SST-RIV) with 7 days between trials in arm curl (elbow flexors) and triceps pulley extension (elbow extensors) performed on the same day.

Results: The SST groups displayed greater acute biceps and triceps brachii (TB) MT versus the TRT session, with no difference in lactate levels between them. The SST-CT resulted in greater biceps and TB MT versus the SST-RIV session. The TTV was greater for the TRT session versus the SST sessions, except in the case of the elbow flexors (no difference was observed between TRT and SST-CT), and higher for the SST-CT versus the SST-RIV.

Conclusion: Trained subjects may benefit from using the SST method as this method may offer a superior MT stimulus and reduced training time, even with a lower TTV.

Effect of 2- vs. 3-Minute Interrepetition Rest Period on Maximal Clean Technique and Performance

Ammar, A, Riemann, BL, Abdelkarim, O, Driss, T, and Hökelmann, A. Effect of 2- vs. 3-minute interrepetition rest period on maximal clean technique and performance. J Strength Cond Res 34(9): 2548-2556, 2020-Currently, it is widely accepted that adopting a long rest period (3-5 minutes) during maximal strength and power exercise is of importance in reducing acute fatigue and maintaining power and technique proficiency. However, despite the fact that weightlifting is an example of maximal strength exercise, only 2 minutes are officially allowed when athletes attempt 2 successive lifts. The purpose of this study was to compare 3- vs. 2-minute intermaximal repetition rest periods (IMRRPs) on performance, rate of perceived exertion (RPE), technical efficiency, and power production during 2 successive maximal repetitions of clean & jerk (C&J). Nine elite weightlifters (age: 24.4 ± 3.6 years, body mass: 77.2 ± 7.1 kg, height 176.0 ± 6.4 cm, and 1 repetition maximum C&J: 170.0 ± 5.0 kg) performed 2 separate testing sessions using 2-minute IMRRP (IMRRP-2) and 3-minute IMRRP (IMRRP-3), in a randomized order, while barbell kinematics and kinetics were recorded. Results showed that the longer IMRRP-3 minutes led to the maintenance of clean technique (from the first to the second repetition) evidenced by a 1.86% lower decline in peak vertical displacement (p = 0.03) and attenuation of increased peak horizontal displacements with a 1.74% (p = 0.03) less backward movement during the first pull, a 3.89% (p = 0.008) less forward movement during the second pull, and a 4.7% (p = 0.005) less backward movement during the catch phase. In addition, attenuation of peak velocity (2.22%; p = 0.02), peak vertical ground reaction force (1.70%; p = 0.03), and peak power (2.14%; p = 0.02) declines were shown using IMRRP-3 compared with IMRRP-2. Increasing IMRRP from 2 to 3 minutes was also shown to decrease RPE values (8.02%; p = 0.008) and to enhance supramaximal C&J performance (1.55%; p = 0.003). The results of this study suggest 3 minutes to be the most advantageous IMRRP in terms of maintaining technical efficiency, power output, reducing fatigue perception, and enhancing performance in elite weightlifters.