Not all unstable devices enhance muscle activation compared to traditional push-ups.

Purpose: To propose the concentric linear velocity measurement as a valid method to quantify load and individualise the prescription of flywheel training, we investigated the relationship between inertial load and mean concentric linear velocity (MCLV) during the flywheel squat exercise in a wide spectrum of intensities. In addition, we compared MCLV and subjective rating of perceived exertion (RPE) after each load.Methods: Twenty-five physically active men volunteered for this study (26.5 ± 2.9 years, 179.5 ± 4.2 cm, 81.6 ± 8.6 kg). After familiarization, all participants performed two inertial progressive load tests on separated days to determine the flywheel load-velocity profile and its reliability. Each participant performed 5 set of 6 repetitions of the flywheel squat exercise with different inertial loads (0.047, 0.104, 0.161, 0.245, 0.321 kg m2) selected in a counterbalanced and randomized order for each testing day. Average MCLV and RPE for each load were compared.Results: The inter-session intraclass correlation coefficient (ICC) showed values above 0.9 in all the included outcomes (MCLV: ICC = 0.91; RPE: ICC = 0.93). A significant correlation (p < 0.01, R2 = 0.80) between inertial load and MCLV was found. Similarly, significant correlation models (p < 0.01) were observed between RPE and load (R2 = 0.87) and (R2 = 0.71) between RPE and MCLV.Conclusion: The control of MCLV during flywheel exercise can be proposed as a valid method to quantify load and to individualize the prescription of flywheel training. In addition, RPE responses have demonstrated significant correlations with load and velocity. Therefore, RPE has been proposed as a valid and reliable alternative to control flywheel training.

BACKGROUND: Cluster Training (CL) is an alternative to traditional training where intra-set breaks are incorporated. Positive effects have been reported on sports performance. However, there is little research on body composition in trained subjects. OBJECTIVE: The aim of this study was to investigate the effects of three cluster training (CL) protocols comprised of different intra-set rest (RIntra) and blocks of repetitions (BK) on strength, power and body composition in individuals maintaining a high protein diet. METHODS: Twenty-nine resistance-trained male participants were randomized to RIntra 20 s and BK 3 RM (n= 8, CL1), RIntra 40 s and BK 3 RM (n= 7, CL2), RIntra 20 s and BK 6 RM (n= 7, CL3), and control group (n= 7, CG). All participants performed two sessions per week of lower-limb resistance training for 8 weeks. RESULTS: There were significant changes in FFM in CL1 (0.9 ± 0.5 kg, P= 0.001, ES = 0.17), CL2 (0.6 ± 0.5 kg, P= 0.010, ES = 0.14) and CL3 (0.6 ± 0.4 kg, P= 0.011, ES = 0.14) but not in CG (0.4 ± 1.1 kg, P= 0.323, ES = 0.13). Likewise, significant increases were found in the cluster groups (CL1, 14.5 ± 12.3, P= 0.012, ES = 0.80; CL2, 10.1 ± 4.3, P= 0.001, ES = 0.60; CL3, 9.5 ± 4.9, P= 0.002, ES = 0.45) but not in CG (9.0 ± 9.0, P= 0.057, ES = 0.55). There were no significant changes for any group in CMJ. CONCLUSIONS: We conclude that a RIntra of ∼ 20 s in CL protocols with 3 RM blocks in multi-joint exercises of the lower-limb is sufficient to elicit significant training adaptations; no additional benefits were obtained using longer rest intervals.

The aim of this study was to compare the concentration of blood lactate [bLa-] and the subjective perception of exertion of trained men in a moderate repetition protocol (MRP) versus a high repetition protocol (HRP) equated for time under tension. Methods A sample of 40 healthy young men (aged, 23.2 ± 4.0 years; height, 177.3 ± 7.0 cm; BMI, 24.3 ± 2.2) performed two sessions of 8 sets of bicep curls with a one-week recovery interval between the trials. In the HRP protocol, 20 repetitions were performed with a cadence of 2 seconds of eccentric and 1 second of concentric, while in the MRP protocol 10 repetitions were performed with 4 seconds of eccentric and 2 seconds of concentric. Cadences were controlled by a metronome. At the beginning and end of each of the sessions, blood lactate was taken at 2, 15, and 30 minutes, and rating of perceived exertion (OMNI-RES) was assessed immediately after completion of each session. Results There were [bLa-] differences between protocols in the MRP 2 min, (5.2 ±1.4); 15 min, (3.2 ±1.2); 30 min, (1.9 ±0.6); p< 0.05, and the HRP 2 min, (6.1 ±1.6); 15 min, (3.7 ±1.1); 30 min, (2.2 ±0.6); p<0.01. OMNI-RES was higher in HRP, (8.8 ±0.7) than in MRP, (7.7 ±0.9). Additionally, a correlation was found between the RPE and [bLa-] values in the HRP protocol (rs = 0.35, p < 0.01).

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(1) Background: Type 1 diabetes mellitus (T1DM) people’s health-related quality of life (HRQoL) is affected by glycemic control. Regular exercise is strongly recommended to these patients due to its cardiovascular and metabolic benefits. However, a large percentage of patients with T1DM people present a sedentary behavior because of the fear of a post-exercise hypoglycemia event, lack of time, lack of motivation and the complicated management of exercise, glycemic and insulin dose interaction. High-intensity interval training (HIIT) is an efficient and safe methodology since it prevents hypoglycemia and does not require much time, which are the main barriers for this population to doing exercise and increasing physical conditioning. (2) Methods: Nineteen sedentary adults (37 ± 6.5 years) with T1DM, were randomly assigned to 6 weeks of either HIIT (12-16-20 × 30-s intervals interspersed with 1-min rest periods) performed thrice weekly, or to the control group, which did not train. HRQoL, sleep quality, exercise motivation and enjoyment were measured as psychological variables. (4) Results: HRQoL improved in physical and social domains, PF (1.9%); PR (80.3%); GH (16.6); SF (34.1%). Sleep quality improved in the HIIT group by 21.4%. Enjoyment improved by 7% and intrinsic motivation was increased by 13%. (5) Conclusions: We suggest that the 6-week HIIT program used in the present study is safe, since no severe hypoglycemia were reported, and an effective strategy in improving HRQoL, sleep quality, exercise motivation and enjoyment which are important psychological well-being factors in T1DM people.

Cardiovascular complications are important causes of morbidity and mortality of Type 1 Diabetes Mellitus (T1DM) people. Regular exercise is strongly recommended to these patients due to its preventive action against this type of disease. However, a large percentage of patients with T1DM people present a sedentary behavior, mainly, because of the fear of a post-exercise hypoglycemia event and lack of time. High-intensity interval training (HIIT) is an efficient and safe methodology since it prevents hypoglycemia and does not require much time, which are the main barriers for this population to doing exercise and increasing physical conditioning. Nineteen sedentary adults (37 ± 6.5 years) with T1DM were randomly assigned to 6 weeks of either HIIT, 12 bouts first 2 weeks, 16 bouts in weeks 3 and 4, and 20 bouts in the last two weeks x 30-s intervals interspersed with 1-min rest periods, performed thrice weekly or to control group, which did not train. VO2max, body composition, heart rate variability (HRV), and fasting glucose were measured as cardiovascular risk factors. We suggest that the 6-week HIIT program used in the present study is safe since no severe hypoglycemia was reported and is an effective strategy in improving VO2max, body composition, HRV, and fasting glucose, which are important cardiovascular risk factors in T1DM people.

Purpose The objective of this study was: (1) to compare the effect of the calculation method using average (Avalue), and best value (Bvalue) of Mean Propulsive Velocity (MPV) on the Load Velocity Profile (LVprofile) during the barbell bench press exercise in elite handball players. In addition, (2) to analyze the relationship between the individual coefficient of variation (CVind) of an incremental load protocol in the bench press exercise with relative strength (Frel) in professional handball players. Methods Nineteen elite international handball players (age 18 [±1] y; body mass 93 [±14] kg; height 191 [±6] cm) performed an incremental test during the barbell bench press exercise. General and individual LVprofile, Frel, and CVind were modelled through MPV and two calculation models (Avalue, vs Bvalue). Results There were significant differences (p < 0.05) between both conditions (Bvalue vs. Avalue). There was an inverse relationship between the Frel and the CVind (r = −0.66, p < 0.001). When CVind was >10% significant differences were found between the two calculations method (Avalue, vs Bvalue). However, no significant differences were found between Avalue, vs Bvalue when the CVind was <10%. Conclusions The calculation method used to assess the barbell bench press LVprofile impacts the nature of the relationship. Regardless CVind values, Avalue is a good choice to determine the LVprofile when the CVind is >10%, if the CVind is <10%, Bvalue will be the better option to determine the LVprofile.