Intraocular Pressure Responses to Four Different Isometric Exercises in Men and Women.

SIGNIFICANCE: The performance of resistance exercise has evidenced to induce abrupt intraocular pressure (IOP) changes, which has been linked to the onset and progression of glaucoma. We found that four different isometric resistance exercises lead to an instantaneous and progressive IOP elevation, with these changes being independent of the type of exercise. PURPOSE: The impact of physical exercise on IOP has demonstrated to be dependent on exercise type and intesity, as well as individuals' characteristics. In this study, we aimed to explore the influence of the load, exercise type, and participant's sex on the IOP behavior during a 2-minute isometric effort. METHODS: Twenty-eight physically active collegiate students performed 2 minutes of isometric exercise in the military press, biceps curl, leg extension, and calf raise exercises against two different loads (high load and low load). Intraocular pressure was measured by rebound tonometry before, during (semicontinuos assessment [24 measurements]), and after 10 seconds of recovery in each of the eight (four exercises × two loads) conditions. RESULTS: We found a statistically significant effect of load (P < .001, np = 0.906), with greater IOP values when performing the isometric exercises against heavier loads. There was a positive IOP rise during the execution of isometric exercise in the high-load condition, returning to baseline levels after 10 seconds of passive recovery. The exercise type and participant's sex did not reveal statistically significant differences (P = .33 and P = .56, respectively). CONCLUSIONS: Our data evidenced an instanteneous and progressive IOP rise during the execution of isometric exercise leading to muscular failure, regardless of the exercise type and participant's sex. After exercise, IOP rapidly retuned to baseline levels (within 10 seconds). The inclusion of glaucoma patients in future studies is guarranteed.

Acute effects of different set configurations during a strength-oriented resistance training session on barbell velocity and the force-velocity relationship in resistance-trained males and females.

PURPOSE: This study explored the acute effects of strength-oriented resistance training sessions performed using three different set configurations on barbell velocity and the force-velocity (F-v) relationship of upper-body muscles in men and women. METHOD: Thirteen men (age: 23.8 ± 2.5 years; 6-repetition maximum [6RM] load: 73.4 ± 15.6 kg) and 13 women (age: 21.5 ± 1.4 years; 6RM load: 32.8 ± 5.2 kg) performed 24 repetitions with a 6RM load during the bench press exercise using traditional (TR: 6 sets of 4 repetitions with 3 min of rest between sets), cluster (CL: 6 sets of 4 repetitions with 15 s of intra-set rest every two repetitions and 2 min and 45 s of rest between sets) and inter-repetition rest (IRR: 1 set of 24 repetitions with 39 s of rest between repetitions) set configurations. The F-v relationship parameters [maximum force (F0), maximum velocity (v0) and maximum power (Pmax)] were determined before and after each training session. RESULTS: The average training velocity did not differ between the three set configurations (p = 0.234), but the IRR set configuration generally provided higher velocities during the last repetition of each set. Significant decreases in F0 (p = 0.001) and Pmax (p = 0.024) but not in v0 (p = 0.669) were observed after the training sessions. Comparable velocity loss was observed for men and women (- 12.1% vs. - 11.3%; p = 0.699). CONCLUSIONS: The administration of very short intra-set rest periods does not allow for the attainment of higher velocities than traditional set configurations during strength-oriented resistance training sessions conducted with the bench press exercise when the work-to-rest ratio is equated.

Selective effects of different fatigue protocols on the function of upper body muscles assessed through the force-velocity relationship.

PURPOSE: This study explored the feasibility of the force-velocity relationship (F-V) to detect the acute effects of different fatigue protocols on the selective changes of the maximal capacities of upper body muscles to produce force, velocity, and power. METHODS: After determining the bench press one-repetition maximum (1RM), participants' F-V relationships were assessed during the bench press throw exercise on five separate sessions after performing one of the following fatiguing protocols: 60%1RM failure, 60%1RM non-failure, 80%1RM failure, 80%1RM non-failure, and no-fatigue. In the non-failure protocols, participants performed half the maximum number of repetitions than in their respective failure protocols. RESULTS: The main findings revealed that (1) all F-V relationships were highly linear (median r = 0.997 and r = 0.982 for averaged across participants and individual data, respectively), (2) the fatiguing protocols were ranked based on the magnitude of power loss as follows: 60%1RM failure > 80%1RM failure > 60%1RM non-failure > 80%1RM non-failure, while (3) the assessed maximum force and velocity outputs showed a particularly prominent reduction in the protocols based on the lowest and highest levels of fatigue (i.e., 80%1RM non-failure and 60%1RM failure), respectively. CONCLUSIONS: The results support the use of F-V to assess the effects of fatigue on the distinctive capacities of the muscles to produce force, velocity, and power output while performing multi-joint tasks, while the assessed maximum force and velocity capacities showed a particularly prominent reduction in the protocols based on the lowest and highest levels of fatigue (i.e., 80%1RM non-failure and 60%1RM failure), respectively.

Optimal Resistive Forces for Maximizing the Reliability of Leg Muscles' Capacities Tested on a Cycle Ergometer.

This study determined the optimal resistive forces for testing muscle capacities through the standard cycle ergometer test (1 resistive force applied) and a recently developed 2-point method (2 resistive forces used for force-velocity modelling). Twenty-six men were tested twice on maximal sprints performed on a leg cycle ergometer against 5 flywheel resistive forces (R1-R5). The reliability of the cadence and maximum power measured against the 5 individual resistive forces, as well as the reliability of the force-velocity relationship parameters obtained from the selected 2-point methods (R1-R2, R1-R3, R1-R4, and R1-R5), were compared. The reliability of outcomes obtained from individual resistive forces was high except for R5. As a consequence, the combination of R1 (≈175 rpm) and R4 (≈110 rpm) provided the most reliable 2-point method (CV: 1.46%-4.04%; ICC: 0.89-0.96). Although the reliability of power capacity was similar for the R1-R4 2-point method (CV: 3.18%; ICC: 0.96) and the standard test (CV: 3.31%; ICC: 0.95), the 2-point method should be recommended because it also reveals maximum force and velocity capacities. Finally, we conclude that the 2-point method in cycling should be based on 2 distant resistive forces, but avoiding cadences below 110 rpm.

Targeting BRAF V600E in metastatic colorectal cancer: where are we today?

Colorectal cancer (CRC) is the second most frequent cause of direct cancer death worldwide. The study of the molecular state of oncogenes has predictive and prognostic value in metastatic CRC (mCRC). The B-raf proto-oncogene (BRAF) gene mutation represents the 8%-12% of all mutations in mCRC. The BRAF V600E mutation, considered the most common alteration of BRAF, corresponds to a constitutive kinase with a high activating capacity of the RAS/RAF/MEK/ERK pathway after a cascade of successive phosphorylations in the transcription of genes. BRAF V600E mutation is more prevalent in women, elderly, right-sided colon cancer and Caucasian population. Unfortunately, it is considered a poor predictive and prognosis biomarker. Patients with mCRC BRAF V600E mutated (BRAFm) are generally associated with poor response to chemotherapy and short progression-free survival and overall survival. Recently, randomised clinical trials have studied the combination of different chemotherapy regimens with angiogenic inhibitors in mCRC BRAFm. In addition, new anti-BRAF and immunotherapy agents have also been studied in this population, with positive results. The objective of this review is to acknowledge the biology and molecular pathway of BRAF, critically analyse the clinical trials and the therapy options published until today and evaluate the options of treatment according to the patient's clinical presentation.

Impact of resistance training sets performed until muscular failure with different loads on intraocular pressure and ocular perfusion pressure.

PURPOSE: The aim of this article is to investigate the acute effects of bench press sets leading to muscular failure with different loads on intraocular pressure and ocular perfusion pressure. STUDY DESIGN: A randomized experimental study. METHODS: Seventeen physically active young men performed four resistance training sets of bench press to muscular failure against different relative loads (65% one-repetition maximum vs 75% one-repetition maximum vs 85% one-repetition maximum vs 95% one-repetition maximum). Intraocular pressure was measured before and immediately after the execution of each of the four sets, and ocular perfusion pressure was also assessed before and after physical effort. RESULTS: We found that intraocular pressure increased after reaching muscular failure (p < 0.001, ƞ²= 0.52), being also dependent on the interaction load × point of measure (p < 0.001, ƞ²= 0.33). Our data demonstrated that higher intraocular pressure increases were found when participants performed the bench press exercise against heavier loads, showing statistical significance for the 75% one-repetition maximum (p = 0.020, d = -0.63, mean change = 0.9 mmHg), 85% one-repetition maximum (p = 0.035, d = -0.56, mean change = 1.4 mmHg), and 95% one-repetition maximum (p < 0.001, d = -1.36, mean change = 2.9 mmHg) relative loads. For its part, ocular perfusion pressure showed a reduction after exercise (p = 0.009, ƞ²= 0.35), being these changes independent on the load used. CONCLUSION: Bench press exercise leading to muscular failure provokes an acute intraocular pressure rise, with greater changes when heavier loads are used. Ocular perfusion pressure exhibited an acute reduction after exercise; however, its clinical relevance seems to be insignificant (lower to 4%). We argue that the use of heavy loads, when training to muscular failure, should be discouraged in order to avoid acute intraocular pressure fluctuations. Future studies should corroborate the generalizability of these findings in glaucoma patients.

The load-velocity profile differs more between men and women than between individuals with different strength levels.

This study aimed to determine the suitability of the load-velocity relationship to prescribe the relative load (%1RM) in women, as well as to compare the load-velocity profile between sexes and participants with different strength levels. The load-velocity relationship of 14 men (1RM: 1.17 ± 0.19) and 14 women (1RM: 0.66 ± 0.13) were evaluated in the bench press exercise. The main findings revealed that: (I) the load-velocity relationship was always strong and linear (R2 range: 0.987-0.993), (II) a steeper load-velocity profile was observed in men compared to women (Effect size [ES]: 1.09), with men showing higher velocities for light loads (ES: - 0.81 and - 0.40 for the y-intercept and 30%1RM, respectively), but women reporting higher velocities for the heavy loads (ES: 1.14 and 1.50 at 90%1RM and 100%1RM, respectively); and (III) while the slope of the load-velocity profile was moderately steeper for weak men compared to their strong counterpart (ES: 1.02), small differences were observed between strong and weak women (ES: - 0.39). While these results support the use of the individual load-velocity relationship to prescribe the %1RM in the bench press exercise for women, they also highlight the large disparities in their load-velocity profile compared to men.

Investigating the Immediate and Cumulative Effects of Isometric Squat Exercise for Different Weight Loads on Intraocular Pressure: A Pilot Study.

BACKGROUND: The execution of resistance exercise against heavy loads promotes an acute intraocular pressure (IOP) rise, which has detrimental effects on ocular health. However, the effect of load on the IOP behavior during exercise remains unknown due to technical limitations. HYPOTHESES: IOP monitoring during isometric squat exercise permits assessment of IOP behavior during physical effort. Second, greater loads will induce a higher IOP rise. STUDY DESIGN: Randomized cross-sectional study. LEVEL OF EVIDENCE: Level 2. METHODS: Twenty-six young adults (13 women, 13 men) performed an isometric squat exercise against 3 loads relative to their maximum capacity (low, medium, and high). IOP was measured before, during (1 measurement every 6 seconds), and after exercise (10 seconds of recovery). RESULTS: There was a progressive IOP rise during exercise, which was dependent on the load applied (Bayes factor10 >100). Higher IOP values were found in the high load condition in comparison with the medium (mean IOP difference = 1.5 mm Hg) and low (mean IOP difference = 3.1 mm Hg) conditions, as well as when the medium load was compared with the low load condition (mean IOP difference = 1.6 mm Hg). Men reached higher IOP values in comparison with women during the last measurements in the high load condition. Ten seconds of recovery were enough to obtain IOP values similar to baseline levels. CONCLUSION: Isometric squat exercise induces an immediate and cumulative IOP elevation, which is positively associated with the load applied. These IOP increments return to baseline values after 10 seconds of recovery, and men demonstrate a more accentuated IOP rise in comparison with women when high levels of effort are accumulated. CLINICAL RELEVANCE: These findings may help in better management of different ocular conditions and highlight the importance of an individualized exercise prescription in clinical populations.

Effect of the level of effort during resistance training on intraocular pressure.

BACKGROUND: We aimed to evaluate the influence of the level of effort during four basic resistance exercises leading to muscular failure on intraocular pressure (IOP) and ocular perfusion (OPP), as well as the role of exercise type and sex. METHODS: Twenty-five young adults (12 women) performed 10 repetitions against their 10-RM (repetition maximum) load in the squat, military press, biceps curl and calf raise exercises. IOP was measured before, during and after exercise, whereas OPP was indirectly assessed before and after each exercise. RESULTS: There was a progressive IOP rise during exercise (p < 0.001, η² = 0.531), which was dependent on exercise type (p = 0.020, η² = 0.125). The squat exercise induced higher IOP increments in comparison to the other exercises (corrected p-values < 0.001), and higher IOP values were found for the military press and biceps curl than for the calf raise exercise (corrected p-values = 0.012 and 0.002). OPP exhibited a significant reduction when leading to muscular failure (p = 0.001, η² = 0.364), being statistically significant for the squat and military press exercises (corrected p-values = 0.037 and 0.047). No effect of sex was found for IOP and OPP (p > 0.05). CONCLUSIONS: A single set of resistance training leading to muscular failure causes an instantaneous and progressive IOP rise in healthy young individuals. These IOP rises depend on exercise type (squat > military press = biceps curl > calf raise), but not on participant´s sex. OPP diminished as a consequence of performing resistance training exercise, being statistically significant for the squat and military press exercises. Future studies should include glaucoma patients aiming to corroborate the generalizability of our findings.

Selective Changes in the Mechanical Capacities of Lower-Body Muscles After Cycle-Ergometer Sprint Training Against Heavy and Light Resistances.

PURPOSE: To explore the feasibility of the linear force-velocity (F-V) modeling approach to detect selective changes of F-V parameters (ie, maximum force [F0], maximum velocity [V0], F-V slope [a], and maximum power [P0]) after a sprint-training program. METHODS: Twenty-seven men were randomly assigned to a heavy-load group (HLG), light-load group (LLG), or control group (CG). The training sessions (6 wk × 2 sessions/wk) comprised performing 8 maximal-effort sprints against either heavy (HLG) or light (LLG) resistances in leg cycle-ergometer exercise. Pre- and posttest consisted of the same task performed against 4 different resistances that enabled the determination of the F-V parameters through the application of the multiple-point method (4 resistances used for the F-V modeling) and the recently proposed 2-point method (only the 2 most distinctive resistances used). RESULTS: Both the multiple-point and the 2-point methods revealed high reliability (all coefficients of variation <5% and intraclass correlation coefficients >.80) while also being able to detect the group-specific training-related changes. Large increments of F0, a, and P0 were observed in HLG compared with LLG and CG (effect size [ES] = 1.29-2.02). Moderate increments of V0 were observed in LLG compared with HLG and CG (ES = 0.87-1.15). CONCLUSIONS: Short-term sprint training on a leg cycle ergometer induces specific changes in F-V parameters that can be accurately monitored by applying just 2 distinctive resistances during routine testing.

Prediction of the Maximum Number of Repetitions and Repetitions in Reserve From Barbell Velocity.

PURPOSE: To provide 2 general equations to estimate the maximum possible number of repetitions (XRM) from the mean velocity (MV) of the barbell and the MV associated with a given number of repetitions in reserve, as well as to determine the between-sessions reliability of the MV associated with each XRM. METHODS: After determination of the bench-press 1-repetition maximum (1RM; 1.15 ± 0.21 kg/kg body mass), 21 men (age 23.0 ± 2.7 y, body mass 72.7 ± 8.3 kg, body height 1.77 ± 0.07 m) completed 4 sets of as many repetitions as possible against relative loads of 60%1RM, 70%1RM, 80%1RM, and 90%1RM over 2 separate sessions. The different loads were tested in a randomized order with 10 min of rest between them. All repetitions were performed at the maximum intended velocity. RESULTS: Both the general equation to predict the XRM from the fastest MV of the set (CV = 15.8-18.5%) and the general equation to predict MV associated with a given number of repetitions in reserve (CV = 14.6-28.8%) failed to provide data with acceptable between-subjects variability. However, a strong relationship (median r2 = .984) and acceptable reliability (CV < 10% and ICC > .85) were observed between the fastest MV of the set and the XRM when considering individual data. CONCLUSIONS: These results indicate that generalized group equations are not acceptable methods for estimating the XRM-MV relationship or the number of repetitions in reserve. When attempting to estimate the XRM-MV relationship, one must use individualized relationships to objectively estimate the exact number of repetitions that can be performed in a training set.