Which Strength Manifestation Is More Related to Regional Swimmers' Performance and In-Water Forces? Maximal Neuromuscular Capacities Versus Maximal Mechanical Maintenance Capacity.

PURPOSE: To explore the association of the load-velocity (L-V) relationship variables and ability to maintain maximal mechanical performance during the prone bench-pull exercise with sprint swimming performance and in-water forces. METHODS: Eleven competitive adult male swimmers (50-m front crawl World Aquatics points: 488 [66], performance level 4) performed 1 experimental session. The L-V relationship variables (L0 [ie,  maximal theoretical load at 0 velocity]; v0 [ie, maximal theoretical velocity at 0 load], and Aline [ie, area under the L-V relationship]) and maximal mechanical maintenance capacity were assessed at the beginning of the session. Afterward, sprint swimming performance and in-water force production were tested through a 50-m front-crawl all-out trial and 15-s fully-tethered swimming, respectively. RESULTS: Only v0 presented high positive associations with 50-m time and swimming kinematics (r > .532; P < .046). The L0, v0, and Aline showed very high positive associations with the in-water forces during tethered swimming (r > .523; P < .049). However, the ability to maintain maximal mechanical performance, assessed by the mean velocity decline during the prone bench pull, was only significantly correlated with stroke rate (r = -.647; P = .016) and stroke index (r = .614; P = .022). CONCLUSIONS: These findings indicate that maximal neuromuscular capacities, especially v0, have a stronger correlation with swimming performance and in-water force production than the ability to maintain maximal mechanical performance in level 4 swimmers.

Impact of Lifting Straps on the Relationship Between Maximum Repetitions to Failure and Lifting Velocity During the Prone Bench Pull Exercise.

BACKGROUND: Fastest mean (MVfastest) and peak (PVfastest) velocity of the set have been proposed to predict the maximum number of repetitions to failure (RTF) during the Smith machine prone bench pull (PBP) exercise. HYPOTHESIS: Goodness-of-fit would be higher for individualized compared with generalized RTF-velocity relationships and comparable for both execution equipment conditions (with or without straps), and the MVfastest and PVfastest associated with each RTF would be comparable between execution equipment and prediction methods (multiple- vs 2-point method). STUDY DESIGN: Cross-sectional study. LEVEL OF EVIDENCE: Level 3. METHODS: After determining the PBP 1-repetition maximum (1RM), 20 resistance-trained male athletes performed 2 sessions randomly, with and without lifting straps, consisting of single sets to failure against the same load sequence (60% to 80% to 70% 1RM). Generalized (pooling data from all subjects) and individualized (separately for each subject using multiple-point or 2-point methods) RTF-velocity relationships were constructed. RESULTS: Individualized RTF-velocity relationships were always stronger than generalized RFT-velocity relationships, but comparable with (MVfastest: r2 = 0.87-0.99]; PVfastest: r2 = 0.88-1.00]) and without (MVfastest: r2 = 0.82-1.00; PVfastest: r2 = 0.89-0.99]) lifting straps. The velocity values associated with each RTF were comparable between execution equipment (P ≥ 0.22), but higher for the multiple-point compared with the 2-point method (P < 0.01). CONCLUSION: The use of lifting straps during the Smith machine PBP exercise does not affect the goodness-of-fit of the RTF-velocity relationships or the velocity values associated with different RTFs. However, caution should be exercised when using different methods. CLINICAL RELEVANCE: The benefits of the RTF-velocity relationships can be extrapolated when using lifting straps, and the 2-point method can also be used as a quick and more fatigue-free procedure. Nevertheless, it is imperative for coaches to ensure that these relationships are reflective of fatigue experienced during training.

Relationship between perceptual and mechanical markers of fatigue during bench press and bench pull exercises: impact of inter-set rest period length.

This study aimed to explore whether the relationship between perceptual (rating of perceived exertion; RPE) and mechanical (maximal number of repetitions completed [MNR], fastest set velocity, and mean velocity decline) variables is affected by the length of inter-set rest periods during resistance training sets not leading to failure. Twenty-three physically active individuals (15 men and eight women) randomly completed 12 testing sessions resulting from the combination of two exercises (bench press and bench pull), three inter-set rest protocols (1, 3, and 5 min), and two minimal velocity thresholds (farther from muscular failure [MVT0.45 for bench press and MVT0.65 for bench pull] and closer to muscular failure [MVT0.35 for bench press and MVT0.55 for bench pull]). The duration of inter-set rest periods did not have a significant impact on RPE values (p ranged from 0.061 to 0.951). Higher proximities to failure, indicated by lower MVTs, were associated with increased RPE values (p < 0.05 in 19 out of 24 comparisons). Moreover, as the number of sets increased, an upward trend in RPE values was observed (p < 0.05 in seven out of 12 comparisons). Finally, while acknowledging some inconsistencies, it was generally observed that higher magnitudes of the mechanical variables, especially MNR (rs < -0.55 in three out of four comparisons), were associated with lower RPE values. These results, which were comparable for the bench press and bench pull exercises, suggest that post-set RPE values are affected by the fatigue experienced at both the beginning and end of the set.

Differences in Various Strength Manifestations Between the Flat and Retracted Bench Press Variants: Are They Affected by Subjects' Experience or Strength Levels?

ABSTRACT: Piepoli, A, Miras-Moreno, S, Janicijevic, D, Martínez-Amat, A, and García-Ramos, A. Differences in various strength manifestations between the flat and retracted bench press variants: are they affected by subjects' experience or strength levels? J Strength Cond Res 37(12): 2339-2345, 2023. The objective of this study was to explore the effect of retracting the scapulae during the free-weight bench press (BP) exercise on various strength manifestations and perceptual variables. Twenty-eight recreationally trained male lifters (BP 1-repetition maximum [1RM] = 96.1 ± 20.8 kg) randomly performed in 2 different sessions: the flat BP (scapulae free to move during the movement) and retracted BP (shoulders retracted during the movement). Three strength manifestations were evaluated: (a) explosive strength -mean velocity (MV) achieved against 3 submaximal loads (40, 60, and 80%1RM); (b) maximal strength -1RM; and (c) endurance strength -number of repetitions completed to failure against the 70%1RM. Discomfort and ratings of perceived exertion (RPE) values were also recorded immediately after completing each test. The upward displacement of the barbell was lower for the retracted BP compared with the flat BP at the 3 submaximal loads ( p ≤ 0.024), but no significant differences between the BP variants were observed for the MV at submaximal loads ( p ≥ 0.473), 1RM ( p = 0.147), number of repetitions completed to failure ( p = 0.447), RPE at submaximal loads ( p ≥ 0.363), or discomfort during any test ( p ≥ 0.611). Subjects always demonstrated a greater strength performance with the BP variant most used in their training programs, but the differences between the flat and retracted BP were not affected by subjects' maximal strength values ( p ≥ 0.162). These results suggest that retracting the scapulae during the BP exercise presents minor effects on different strength manifestations and perceptual measures of effort and discomfort.

Lifting velocity predicts the maximum number of repetitions to failure with comparable accuracy during the Smith machine and free-weight prone bench pull exercises.

This study compared the accuracy of the fastest mean velocity from set (MVfastest) to predict the maximum number of repetitions to failure (RTF) between 2 variants of prone bench pull (PBP) exercise (Smith machine and free-weight) and 3 methods (generalized, individualized multiple-point, and individualized 2-point). Twenty-three resistance-trained males randomly performed 2 sessions during Smith machine PBP and 2 sessions during free-weight PBP in different weeks. The first weekly session determined the RTF-MVfastest relationships and subjects completed single sets of repetitions to failure against 60-70-80-90%1RM. The second weekly session explored the accuracy of RTFs prediction under fatigue conditions and subjects completed 2 sets of 65%1RM and 2 sets of 85%1RM with 2 min of rest. The MVfastest associated with RTFs from 1 to 15 were greater for Smith machine compared to free-weight PBP (F ≥ 42.9; P < 0.001) and for multiple-point compared to 2-point method (F ≥ 4.6; P ≤ 0.043). The errors when predicting RTFs did not differ between methods and PBP variants, whereas all RTF-MVfastest relationships overestimated the RTF under fatigue conditions. These results suggest that RTF-MVfastest relationships present similar accuracy during Smith machine and free-weight PBP exercises and it should be constructed under similar training conditions.

A single dose of dihydrocapsiate does not improve neuromuscular performance in resistance-trained young adults: A randomised, triple-blinded, placebo-controlled, crossover trial.

Capsinoids may exert ergogenic effects on resistance exercises. However, the acute effects of capsinoids on neuromuscular performance in humans are unknown. Here, we aimed to investigate the acute effects of dihydrocapsiate on lower- and upper-body neuromuscular performance parameters in resistance-trained individuals. 25 young adults (n = 6 women; age = 26 ± 3 years; body mass index = 24.3 ± 2.8 kg/m2) with ≥ 1-year resistance training experience were included in this triple-blind (participants, intervention researchers, and data analysts were blinded), placebo-controlled, crossover study. Lower- and upper-body ballistic strength (countermovement jump [CMJ] height and bench press throw [BPT] peak velocity), maximum dynamic strength (estimated 1 repetition maximum in squat and bench press [BP]), and strength-endurance (mean set velocity [squat] and number of repetitions to failure [bench press]) were assessed in 2 independent sessions (≥7 days separation). Participants ingested 12 mg of dihydrocapsiate or placebo 30 min before each trial. We found no significant differences between dihydrocapsiate and placebo conditions in ballistic strength, (CMJ height 33.20 ± 8.07 vs 33.32 ± 7.85 cm; BPT peak velocity 2.82 ± 0.77 vs 2.82 ± 0.74 m/s) maximal dynamic strength (estimated squat 1RM: 123.76 ± 40.63 vs 122.66 ± 40.97 kg; estimated BP 1RM: 99.47 ± 43.09 vs 99.60 ± 43.34 kg), and strength-endurance (squat mean set velocity 0.66 ± 0.07 vs 0.66 ± 0.05 m/s; number BP repetitions to failure 13.00 ± 3.56 vs 13.00 ± 4.78) (all P ≥ 0.703). We conclude that dihydrocapsiate does not acutely improve neuromuscular performance in trained young adults.

Capsinoids ­ non-pungent analogs of capsaicin ­ have been recently proposed as potential ergogenic compounds in humans.However, the effects of a single dose of capsinoids on neuromuscular performance parameters in humans remains unknown.12 mg of dihydrocapsiate does not improve neuromuscular performance in resistance-trained young adults.Dihydrocapsiate should not be recommended as an ergogenic aid to acutely increase neuromuscular performance.

Effect of a High-Intensity Handball-Specific Fatigue Protocol Focused on the Leg Contralateral to the Throwing Arm on Interlimb Asymmetries.

ABSTRACT: Janicijevic, D, Pérez-Castilla, A, Miras-Moreno, S, Ortega-Becerra, M, Morenas-Aguilar, MD, Smajla, D, Sarabon, N, and García-Ramos, A. Effect of a high-intensity handball-specific fatigue protocol focused on the leg contralateral to the throwing arm on interlimb asymmetries. J Strength Cond Res 37(7): 1382-1389, 2023-This study aimed to elucidate which countermovement jump (CMJ) variant (unilateral or bilateral) is more sensitive to detect the decrement in kinetic CMJ-derived variables of the leg more actively involved in a handball-specific fatigue protocol. Seventeen female handball players (age: 20.6 ± 2.5 years) performed a fatigue protocol consisting of 8 repetitions of the following circuit separated by 10 seconds: 10 m sprint, 180° change of direction with the leg contralateral to the throwing arm, 10 m sprint with ball reception at 7 m, and handball throw preceded by a jump over a 40 cm hurdle with the leg contralateral to the throwing arm. Before and after the fatigue protocol, 6 unilateral CMJs (3 with each leg) and 3 bilateral CMJs were performed on a dual Kistler force platform (model 9260AA6). Bilateral CMJ height was reduced by 5.4% after the fatigue protocol (p < 0.001). However, the fatigue protocol did not promote any significant change in peak force, mean force, and propulsive impulse or in their asymmetry values (17 of 18 comparisons). The decrement of 6.1% during the unilateral CMJ in the propulsive impulse developed by the leg ipsilateral to the throwing arm (less involved in the fatigue protocol) was the only variable that reached statistical significance (p = 0.038). The pre-post fatigue changes in asymmetry values presented negligible correlations between both CMJ variants (rs = 0.01 to -0.19). These results suggest that neither unilateral nor bilateral CMJs are able to detect changes in interlimb asymmetries after a high-intensity handball-specific fatigue protocol.

Effects of phenylcapsaicin on aerobic capacity and physiological parameters in active young males: a randomized, triple-blinded, placebo-controlled, crossover trial.

Objective: Phenylcapsaicin (PC) is a new capsaicin analog which has exhibited a higher bioavailability. This sudy assessed the effects of a low dose (LD) of 0.625 mg and a high dose (HD) of 2.5 mg of PC on aerobic capacity, substrate oxidation, energy metabolism and exercise physiological variables in young males. Materials and methods: Seventeen active males (age = 24.7 ± 6.0 years) enrolled to this randomized, triple-blinded, placebo-controlled, crossover trial. Participants attended the laboratory on 4 sessions separated by 72-96 h. A submaximal exercise test [to determine maximal fat oxidation (MFO) and the intensity at MFO (FATmax)] followed by a maximal incremental test (to determine VO2max) were performed in a preliminary session. The subsequent sessions only differed in the supplement ingested [LD, HD or placebo (PLA)] and consisted of a steady-state test (60 min at FATmax) followed by a maximal incremental test. Energy metabolism, substrate oxidation, heart rate, general (gRPE) and quadriceps (RPEquad) rate of perceived exertion, skin temperature and thermal perception were tested. Results: Clavicle thermal perception was lower in HD compared to PLA and LD (p = 0.04) across time. HD reduced maximum heart rate in comparison to PLA and LD (p = 0.03). LD reported higher general RPE (RPEg) values during the steady-state test compared to PLA and HD across time (p = 0.02). HD and LD elicited higher peak of fat oxidation during the steady-state test compared with PLA (p = 0.05). Intra-test analyses revealed significant differences for fat oxidation (FATox) in favor of HD and LD compared to PLA (p = 0.002 and 0.002, respectively), and for carbohydrate oxidation (CHOox) (p = 0.05) and respiratory exchange ratio (RER) (p = 0.03) for PLA. In the incremental test, only general RPE at 60% of the maximal intensity (W) differed favoring HD (p ≤ 0.05). Conclusion: Therefore, PC may contribute to increase aerobic capacity through the improvement of fat oxidation, maximum heart rate and perceptual responses during exercise.

Two-point Method Applied in Field Conditions: A Feasible Approach to Assess the Load-Velocity Relationship Variables During the Bench Pull Exercise.

ABSTRACT: Miras-Moreno, S, García-Ramos, A, Jukic, I, and Pérez-Castilla, A. Two-point method applied in field conditions: a feasible approach to assess the load-velocity relationship variables during the bench pull exercise. J Strength Cond Res 37(7): 1367-1374, 2023-This study explored the between-session reliability and concurrent validity of the load-velocity (L-V) relationship variables obtained from different methods during the Smith machine bench pull exercise. In a counterbalanced order, 23 resistance-trained male subjects performed 2 sessions against 6 different loads in one week and 2 sessions against the lightest and heaviest loads in another week. The L-V relationship variables (load-axis intercept [ L0 ], velocity-axis intercept [ v0 ], and area under the L-V relationship line [ Aline ]) were obtained using the mean and peak velocity by the standard multiple-point (all 6 loads were used for the L-V modeling), modified multiple-point (the data point that most reduced the coefficient of determination was omitted from the L-V modeling), and 2-point (only 2 loads were used for the L-V modeling) methods. The reliability of the L-V relationship variables was acceptable for all methods (within-subjects coefficient of variation [CV] = 2.09-9.21%). The standard multiple-point and 2-point methods provided greater reliability for all L-V relationship variables compared with the modified multiple-point method (CV ratio ≥ 1.27), while the 2-point method provided similar (CV ratio = 1.04 for Aline ) or greater (CV ratio = 1.50 for L0 and 1.62 for v0 ) reliability than the standard multiple-point method. The concurrent validity of the modified multiple-point and 2-point methods was acceptable for the L-V relationship variables (effect size ≤ 0.62; r ≥ 0.76). These results suggest that the 2-point method is not only a valid procedure but also more reliable, simpler, faster, and less prone to fatigue than multiple-point methods for assessing maximal neuromuscular capacities through the L-V relationship.

Selective Effect of Different High-Intensity Running Protocols on Resistance Training Performance.

ABSTRACT: Pérez-Castilla, A, García-Pinillos, F, Miras-Moreno, S, Ramirez-Campillo, R, García-Ramos, A, and Ruiz-Alias, SA. Selective effect of different high-intensity running protocols on resistance training performance. J Strength Cond Res 37(6): e369-e375, 2023-This study aimed to explore the acute effect of 2 high-intensity running protocols (high-intensity interval training [HIIT] and sprint interval training [SIT]) on resistance training (RT) performance and their combined effect on the lower-body maximal neuromuscular capacities. Eighteen healthy subjects randomly completed 3 experimental protocols: only RT, HIIT + RT, and SIT + RT. Characteristics of the RT protocol include 3 back-squat sets of 10 repetitions or 20% velocity loss against 60% of 1 repetition maximum with 3 minutes of interset rest. Characteristics of the high-intensity running protocols include HIIT (4 intervals of 4 minutes at ∼110% of functional threshold power with 3 minutes of interinterval rest) and SIT (6 all-out sprints of 30 seconds with 4 minutes and 24 seconds of interinterval rest). The force-velocity relationship (maximal values of force [ F0 ], velocity [ v0 ], and power [P max ]) was evaluated at the beginning and at the end of each experimental protocol. The number of back-squat repetitions ( p = 0.006; effect size [ES] = -0.96), fastest velocity ( p = 0.003; ES = -0.63), and average velocity ( p = 0.001; ES = -0.73) were lower for the SIT + RT protocol compared with the RT protocol, but no significant differences were observed between the RT and HIIT + RT ( p ≥T0.057; ES ≤.-0.46, except -0.82 for the number of back-squat repetitions) and HIIT + RT and SIT + RT ( p ≥T0.091; ES .0-0.35) protocols. The 3 protocols induced comparable decreases in v0 and P max ( F(2,34) 2,0.96; p ≥ 0.393), but F0 tended to decrease after the SIT + RT protocol and to increase after the RT and HIIT + RT protocols ( F(2,34) = 4.37; p = 0.035). Compared with RT alone, the data suggest that SIT deteriorates RT quality and F0 capacity more than long-interval HIIT.

Velocity Loss Is Not an Accurate Predictor of the Percentage of Completed Repetitions During the Prone Bench Pull Exercise.

ABSTRACT: Pérez-Castilla, A, Miras-Moreno, S, Janicijevic, D, and García-Ramos, A. Velocity loss is not an accurate predictor of the percentage of completed repetitions during the prone bench pull exercise. J Strength Cond Res 37(5): 1001-1008, 2023-The primary aim of this study was to explore the goodness of fit and accuracy of both general and individual relationships between the magnitude of velocity loss (%VL) and the percentage of performed repetitions with respect to the maximal number of repetitions that can be completed to failure (%Rep) during the Smith machine prone bench pull exercise. Fifteen male sports science students completed a preliminary session to determine the bench pull one-repetition maximum (1RM) and 2 identical experimental sessions separated by 48-72 hours. In each experimental session, subjects randomly performed single sets of repetitions to failure separated by 10 minutes against the 60% 1RM, 70% 1RM, and 80% 1RM during the Smith machine bench pull exercise. Individual %Rep-%VL relationships presented a greater goodness of fit than general %Rep-%VL relationships at the 60% 1RM ( R2 = 0.85-0.97 vs. 0.79-0.85), 70% 1RM ( R2 = 0.84-0.99 vs. 0.77-0.84), and 80% 1RM ( R2 = 0.84-1.00 vs. 0.74-0.80). However, the accuracy (absolute errors) in estimating the %Rep during the second testing session based on the %Rep-%VL equations obtained in the first testing session did not differ between the individual and general %Rep-%VL equations in 8 of 9 comparisons ( p ≥ 0.102). The absolute errors between the actual and predicted %REP were unacceptable (>10%) in 11 of 18 comparisons, and acceptable (5-10%) in 7 of 18 comparisons. These results highlight that the %Rep cannot be estimated with high degree of accuracy from VL recordings during the Smith machine bench pull exercise, regardless of whether individual or general Rep-%VL relationships are considered.

Relationship Between the Number of Repetitions in Reserve and Lifting Velocity During the Prone Bench Pull Exercise: An Alternative Approach to Control Proximity-to-Failure.

ABSTRACT: Pérez-Castilla, A, Miras-Moreno, S, Weakley, J, and García-Ramos, A. Relationship between the number of repetitions in reserve and lifting velocity during the prone bench pull exercise: an alternative approach to control proximity-to-failure. J Strength Cond Res 37(8): 1551-1558, 2023-This study aimed to explore the goodness-of-fit and accuracy of both general and individual relationships between the number of repetitions in reserve (RIR) and the repetition velocity during the Smith machine prone bench pull exercise. Fifteen male sports science students completed 3 sessions separated by 48-72 hours. The first session was used to determine the bench pull 1 repetition maximum (1RM). The second and third sessions were identical and consisted of 3 single sets (60, 70, and 80% 1RM) of repetitions to momentary muscular failure separated by 10 minutes during the Smith machine prone bench pull exercise. General (i.e., pooling together the data from the 15 subjects) and individual RIR-velocity relationships were constructed from the data collected in the second session by pooling the data from the 3 loads (multiple-loads) or specifically for each load (load-specific). The 4 RIR-velocity relationship models were ranked by their goodness-of-fit as follows: individual load-specific ( r = 0.93) > individual multiple-loads ( r = 0.83) > general multiple-loads ( r = 0.65) > general load-specific ( r = 0.61). The accuracy when predicting the RIR in the third session based on the RIR-velocity equations obtained in the second session was acceptable and comparable for the 4 RIR-velocity relationship models (absolute errors ≤2 RIR). However, the 4 RIR-velocity relationship models significantly underestimated the RIR for ≥1 RIR and overestimated the RIR for 0 RIR. These results suggest that the 4 RIR-velocity relationship models are equally effective to quantify proximity-to-failure during the Smith machine prone bench pull exercise.

Validation of a Novel Reaction Time Test Specific for Military Personnel.

A military-specific reaction time (RT) test was developed to explore its reliability and sensitivity to discriminate between military personnel and sport science students. Fifteen male professional Spanish soldiers and 16 male sport science students completed two RT test modalities: military-specific and nonspecific RT tests. For each RT test modality, both the Simple (i.e., one stimulus, one response) and the Go, No-Go RT (i.e., true, and false stimuli, one response) were tested. The military-specific RT test consisted of a video presented through virtual reality glasses of a forest environment in which soldiers would appear from behind different bushes (stimuli) and the response consisted of pressing the button of a gun-shaped mouse (when they saw a soldier pointing a rifle at them). Both Simple and Go, No-Go RT reached acceptable reliability in both populations (coefficient of variation ≤ 9.64%). Military personnel presented a lower RT than sport science students during the military-specific RT test (p ≤ .001), while no differences were obtained during the nonspecific RT test. RT values were not significantly correlated between the military-specific and nonspecific RT tests (r ≤ .02). These findings collectively suggest that the novel military-specific RT test is an ecologically valid alternative to evaluate the information processing abilities of military personnel.

Caffeine ingestion attenuates diurnal variation of lower-body ballistic performance in resistance-trained women.

ABSTRACTThe present study investigates the effect of an acute intake of caffeine on the diurnal variation of neuromuscular performance in resistance-trained women. A total of 15 resistance-trained women participated in the current triple-blind, placebo-controlled, crossover experimental study. We assessed neuromuscular performance (i.e. ballistic (countermovement jump [CMJ] height and bench press throw [BPT] peak velocity), maximal strength (squat and bench press [BP] one-repetition maximum [1RM]), and strength-endurance [average velocity of the set during squat and number of repetitions-to-failure in BP]) four times at within 7 days. The participants ingested an acute dose of caffeine (3 mg/kg) or a placebo at 9-11 am and/or 17-19 pm. CMJ height (P = .016) and BP peak velocity (P = .012) were higher in the afternoon than in the morning. Compared to placebo, caffeine intake increased CMJ height by 3.1% in the morning and 1.6% in the afternoon (P = .035), but it had no effect on BPT peak velocity (P = .381). Maximal strength and strength-endurance performances were not affected by the time-of-day or caffeine intake (all P > .3). No significant interaction (time-of-day x substance) was observed in any of the above-mentioned outcomes (all P > .1). In conclusion, an acute dose of caffeine in the morning was effective to restore CMJ performance to levels found in the afternoon, while this effect was not observed neither in BPTpeak velocity nor in lower- and upper-body maximal strength and strength-endurance performance. Moreover, lower- and upper-body ballistic performance were greater in the afternoon than in the morning in resistance-trained women, while the acute intake of caffeine was only effective to increase CMJ height.HighlightsBallistic performance is probably higher in the afternoon than in the morning in resistance-trained women.An acute intake of caffeine is effective to increase countermovement jump performance.The ingestion of an acute dose of caffeine in the morning restored countermovement jump performance to levels found in the afternoon.

Optimizing mechanical performance in the bench press: The combined influence of inter-set rest periods and proximity to failure.

This study examined the influence of inter-set rest periods of 1 (R1), 3 (R3) and 5 (R5) minutes on the number of repetitions completed before exceeding the minimum velocity thresholds of 0.45 m⋅s-1 (MVT0.45) and 0.35 m⋅s-1 (MVT0.35) during the bench press exercise. Twenty-three physically active individuals, 15 men and eight women, randomly completed six testing sessions consisting of four sets of the bench press exercise performed with maximal intent against 75% of the one-repetition maximum. Testing sessions differed in the length of inter-set rest periods (R1, R3, and R5) and MVT applied (MVT0.45 and MVT0.35). The number of repetitions was lower using shorter inter-set rest periods (R1 < R3 < R5), but R3 was more similar to R1 and R5 using MVT0.45 and MVT0.35, respectively. The fastest velocity of the set was reduced with the increment in the number of sets for the three protocols using MVT0.35 (greater reduction for shorter rest periods), but it was only reduced for R1 when using MVT0.45. The results suggest that, to maintain bench press mechanical performance, 5-min inter-set rest periods are necessary when sets are terminated close to failure (MVT0.35), while 3 min may suffice when sets are terminated farther from failure (MVT0.45).

Intraocular pressure responses to a virtual reality shooting simulation in active-duty members of the Spanish Army: The influence of task complexity.

Ocular physiology is sensitive to cognitively demanding tasks. However, it is unknown whether the intraocular pressure is also affected by the cognitive demands of military operations. The main objective was to determine the impact of a virtual reality shooting simulation with two levels of complexity on intraocular pressure levels in military personnel. Eighteen active-duty members of the Spanish Army and eighteen civilians performed two 4 min simulated shooting tasks with two levels of complexity using a virtual reality. In the "easy" task participants performed a simulated shoot when the stimulus (military with a rifle) appeared, while in the "difficult" task the stimulus randomly was a military with a rifle or with his hands on the air and participants were instructed to respond only when the military with a rifle appeared. Intraocular pressure was measured with a rebound tonometer before and immediately after each task. Complementarily, perceived levels of mental load and shooting performance (reaction time) were assessed. Intraocular pressure was greater after completing the more complex task in both military personnel (p-value < 0.01, Cohen´s d = 1.19) and civilians (p-value < 0.01, Cohen´s d = 1.16). Also, perceived levels of task load and reaction time were higher in the difficult compared to the easy shooting tasks (both p < 0.001). The rise in intraocular pressure is positively associated with the cognitive demands of simulated military operations. The potential application of this finding is the development of objective tools based on intraocular pressure for the evaluation of the mental state in real-world contexts, permitting to improve soldiers´ safety and performance.

Association of military-specific reaction time performance with physical fitness and visual skills.

Background: The aim of the present study was to explore whether military-specific reaction time (RT) test performance is affected by individuals' physical and visual skills. Method: In a single testing session, the military-specific Simple and Go, No-Go RT, aerobic power (20-m Multistage Shuttle Run test), maximal upper- and lower-body mechanical capacities (bench press and squat against different loads), and visual skills (multiple object tracking and dynamic visual acuity) of 30 young men (15 active-duty military personnel and 15 sport science students) were evaluated. Results: The main findings revealed that the Simple RT and Go, No-Go RT presented (1) with aerobic power non-significant small correlations in military personnel (r = -0.39 and -0.35, respectively) and non-significant negligible correlations in sport science students (r = -0.10 and 0.06, respectively), (2) inconsistent and generally non-significant correlations with the maximal mechanical capacities of the upper- and lower-body muscles (r range = -0.10, 0.67 and -0.27, 0.48, respectively), (3) non-significant correlations with visual skills (r magnitude ≥ 0.58) with the only exception of the Go, No-Go RT that was significantly correlated to all visual variables in the group of students (i.e., students who achieved better results during visual tests had shorter RT; r magnitude ≥ 0.58), and (4) none of the physical and visual variables significantly predicted the Simple RT or Go, No-Go RT. Conclusion: Altogether, these results indicate that military-specific RT performance is generally independent of physical and visual skills in both military personnel and active university students.

Lifting Velocity as a Predictor of the Maximum Number of Repetitions That Can Be Performed to Failure During the Prone Bench Pull Exercise.

OBJECTIVE: To explore (1) the goodness of fit of generalized and individualized relationships between the maximum number of repetitions performed to failure (RTF) and the fastest mean velocity and peak velocity of the sets (RTF-velocity relationships), (2) the between-sessions reliability of mean velocity and peak velocity values associated with different RTFs, and (3) whether the errors in the prediction of the RTF under fatigued and nonfatigued conditions differ between generalized and individualized RTF-velocity relationships. METHODS: Twenty-three sport-science students performed 4 testing sessions with the prone bench pull exercise in a Smith machine: a 1-repetition-maximum [1RM] session, 2 identical sessions consisting of singles sets of RTF against 4 randomized loads (60%-70%-80%-90%1RM), and 1 session consisting of 4 sets of RTF against the 75%1RM. RESULTS: Individualized RTF-velocity relationships presented a higher goodness of fit (r2 = .96-.97 vs .67-.70) and accuracy (absolute errors = 2.1-2.9 repetitions vs 2.8-4.3 repetitions) in the prediction of the RTF than generalized RTF-velocity relationships. The reliability of the velocity values associated with different RTFs was generally high (average within-subject coefficient of variation = 4.01% for mean velocity and 3.98% for peak velocity). The error in the prediction of the RTF increased by ~1 repetition under fatigue (ie, set 1 vs sets 2-4). CONCLUSIONS: Individualized RTF-velocity relationships can be used with acceptable precision and reliability to prescribe the loads associated with a given RTF during the match a specific XRM during the prone bench pull exercise, but a lower accuracy is expected in a fatigued state.

Velocity Performance Feedback During the Free-Weight Bench Press Testing Procedure: An Effective Strategy to Increase the Reliability and One Repetition Maximum Accuracy Prediction.

ABSTRACT: Jiménez-Alonso, A, García-Ramos, A, Cepero, M, Miras-Moreno, S, Rojas, FJ, and Pérez-Castilla, A. Velocity performance feedback during the free-weight bench press testing procedure: An effective strategy to increase the reliability and one repetition maximum accuracy prediction. J Strength Cond Res 36(4): 1077-1083, 2022-This study aimed to determine whether the verbal provision of velocity performance feedback during the free-weight bench press (BP) exercise influences (a) the within-session reliability and magnitude of mean concentric velocity (MCV) values recorded against a range of submaximal loads and (b) the accuracy of the individualized load-velocity profile to estimate the BP 1 repetition maximum (1RM). Fifteen men (BP 1RM relative to body mass = 1.08 ± 0.22) performed an incremental loading test until reaching the 1RM on 2 separate sessions. Subjects received verbal velocity performance feedback in 1 session (knowledge of results [KR]), and no KR was provided in another session (Control). A linear velocity transducer was used to collect the MCV against 4 loads (40-55-70-85% 1RM), and the BP 1RM was estimated from the individualized load-velocity relationship modeled through the multiple-point (40-55-70-85% 1RM) and 2-point methods (40-85% 1RM). The KR condition provided a higher reliability (coefficient of variation [CV]: KR = 2.41%, Control = 3.54%; CV ratio = 1.47) and magnitude (p = 0.001; effect size [ES] = 0.78) of MCV for the 40% 1RM, but no significant differences in reliability (CV ratio ≤1.15) nor in the magnitude (p ≥ 0.058; ES range = 0.00-0.32) were observed for higher loads. The accuracy in the estimation of the 1RM was higher for the KR (absolute errors: multiple-point = 3.1 ± 2.3 kg; 2-point = 3.5 ± 2.1 kg) compared with the Control condition (absolute errors: 4.1 ± 1.9 kg for both multiple-point and 2-point methods). These results encourage the provision of verbal velocity performance feedback during BP testing procedures.

Effect of Augmented Feedback on Velocity Performance During Strength-Oriented and Power-Oriented Resistance Training Sessions.

ABSTRACT: Jiménez-Alonso, A, García-Ramos, A, Cepero, M, Miras-Moreno, S, Rojas, FJ, and Pérez-Castilla, A. Effect of augmented feedback on velocity performance during strength-oriented and power-oriented resistance training sessions. J Strength Cond Res 36(6): 1511-1517, 2022-This study examined the effects of providing instantaneous velocity feedback (knowledge of results [KR]) on velocity maintenance across multiple sets during strength-oriented and power-oriented resistance training (RT) sessions. Seventeen men completed 2 strength-oriented RT sessions (4 sets of 5 repetitions at 75% of 1 repetition maximum [1RM] during the back squat [SQ] and bench press [BP] exercises) in 1 week and 2 power-oriented RT sessions (4 sets of 5 repetitions at 30% of 1RM during the countermovement jump [CMJ] and BP throw [BPT] exercises) in another week. Subjects received verbal velocity performance feedback in 1 session (KR) and no KR was provided in another session. Greater velocities during the 4 sets of both strength-oriented (from 4.6 to 11.6%) and power-oriented (from 1.4 to 3.5%) RT sessions were observed. The increments in velocity performance during the KR condition were greater for the CMJ (2.25 ± 0.14 vs. 2.18 ± 0.17 m·s-1; 3.0%) than the BPT (2.33 ± 0.13 vs. 2.29 ± 0.16 m·s-1; 1.7%) and similarly for the SQ (0.59 ± 0.07 vs. 0.55 ± 0.06 m·s-1; 7.5%) and BP (0.47 ± 0.09 vs. 0.44 ± 0.07 m·s-1; 7.8%). The raw differences in the RT velocity for BPT were positively correlated with the raw differences in the RT velocity for SQ (r = 0.524; p = 0.031) and CMJ (r = 0.662; p = 0.004), but the remaining correlations did not reach a statistical significance (r ≤ 0.370; p ≥ 0.123). Although these results support the provision of velocity performance feedback to increase training quality regardless of the type of RT session, the positive effect of KR seems to be more accentuated during strength-oriented compared with power-oriented RT sessions.