ABSTRACT Objective Sulfonylureas have been used to improve performance in strength sports. However, this hypothetical effect has not been proven. We examined the ergogenic acute effect of gliclazide on resistance training performance and muscle recovery. Subjects and methods We conducted a double-blind, randomized, crossover pilot study with 10 healthy resistance-trained adults (29.3 ± 4.4 years), nonusers of anabolic steroids. The participants were randomized to two exercise sessions. In the first session, five participants received placebo and the other five received gliclazide modified release, both administered 8 hours before the session. Session two was performed in a crossover fashion a week later. The volume load was calculated as the maximum number of repetitions of four sets multiplied by load (65% 1-RM). Blood samples were collected before and after exercise, as well as 24 hours and 48 hours after exercise for measurement of creatine kinase (CK-MM) and lactate dehydrogenase (LDH) activity. Blood glucose was measured with a glucometer before, during, and after the exercise sessions. Results Gliclazide did not enhance volume load for bench press (placebo: 2,698.0 ± 923.0 kg; gliclazide: 2,675.0 ± 1,088.0 kg; p = 0.073) or leg press (placebo: 10,866.0 ± 2,671.0 kg; gliclazide: 10,817.0 ± 2,888.0 kg; p = 0.135). However, CK-MM (-27.7%; p = 0.034) and LDH (-21.1%; p = 0.021) activities were decreased with gliclazide 48 hours after exercise. There was also a decrease in blood glucose in the gliclazide compared with the placebo session (p = 0.018). Conclusion Gliclazide did not enhance performance in a single resistance training session, but promoted faster muscle recovery. The decrease in blood glucose post-exercise with gliclazide was an undesirable effect that could lead to long-term glucose metabolism disorders. Registered in ClinicalTrials.gov under number NCT04443777. sports However proven recovery doubleblind, doubleblind double blind, blind double-blind 1 resistancetrained trained 29.3 293 29 3 (29. 44 4 4. years, years , years) steroids sessions release later 65% 65 (65 1RM. 1RM RM . 1-RM) 2 CKMM CK MM (CK-MM (LDH activity during (placebo 26980 698 0 2,698. 9230 923 923. kg 26750 675 2,675. 10880 088 1,088. 0.073 0073 073 108660 866 10,866. 26710 671 2,671. 108170 817 10,817. 28880 888 2,888. 0.135. 0135 0.135 135 0.135) 27.7% 277 27 7 (-27.7% 0.034 0034 034 21.1% 211 21 (-21.1% 0.021 0021 021 0.018. 0018 0.018 018 0.018) postexercise post longterm long term disorders ClinicalTrialsgov ClinicalTrials gov NCT04443777 NCT 29. (29 6 (6 1-RM 2698 69 2,698 92 2675 67 2,675 1088 08 1,088 0.07 007 07 10866 86 10,866 2671 2,671 10817 81 10,817 2888 88 2,888 013 0.13 13 27.7 (-27.7 0.03 003 03 21.1 (-21.1 0.02 002 02 001 0.01 01 NCT0444377 (2 ( 269 2,69 9 267 2,67 108 1,08 0.0 00 1086 10,86 1081 10,81 288 2,88 0.1 27. (-27. 21. (-21. NCT044437 26 2,6 1,0 0. 10,8 28 2,8 (-27 (-21 NCT04443 2, 1, 10, (-2 NCT0444 (- NCT044 NCT04 NCT0

Abstract Background: Conventional aerobic training is the first choice in cardiac rehabilitation for patients with chronic heart failure (CHF). However, high-intensity interval training (HIIT) may be an alternative, although it has little evidence. Objectives: To evaluate the effect of continuous aerobic training (CAT) or HIIT on exercise tolerance in CHF patients. Methods: Retrospective study with 30 patients, of both genders, members of a 10-week CAT or HIIT program. The control group (CON) consisted of patients who did not participate voluntarily in the program. Peak oxygen uptake (VO2peak), thresholds (LV1 and LV2), and ventilatory efficiency in the production of dioxide (VE/VCO2 slope), oxygen uptake efficiency (OUES), and VO2 recovery kinetics were analyzed. A two-way or repeated measures ANOVA was used, followed by Fisher's post-hoc test (p<0.05). Results: After 10 weeks of training, the CAT group increased the treadmill speed at LV1 (p=0.040), while the HIIT increased both the speed (p=0.030) and incline of the treadmill (p<0.001) for VO2peak and LV2, as well as the total time of the cardiopulmonary test. The VE/VCO2 slope was lower than that predicted for CAT (p=0.003) and HIIT (p=0.008). There was no change in VO2peak, recovery of heart rate (HR), and VO2, VE/VCO2, and OUES in both groups. Conclusions: After 10 weeks, both CAT and HIIT increased the tolerance to physical exercise. However, HIIT showed improvement in more parameters, differently from CAT.

ABSTRACT Objective To analyze respiratory mechanics and hemodynamic alterations in an experimental model of chronic heart failure (CHF) following myocardial infarction. Method Twenty-seven male adult Wistar rats were randomized to CHF group (n=12) or Sham group (n=15). Ten weeks after coronary ligation or sham surgery, the animals were anesthetized and submitted to respiratory mechanics and hemodynamic measurements. Pulmonary edema as well as cardiac remodeling were measured. Results The CHF rats showed pulmonary edema 26% higher than the Sham group. The respiratory system compliance (Crs) and the total lung capacity (TLC) were lower (40% and 27%, respectively) in the CHF rats when compared to the Sham group (P<0.01). There was also an increase in tissue resistance (Gti) and elastance (Hti) (28% and 45%, respectively) in the CHF group. Moreover, left ventricular end-diastolic pressure was higher (32 mmHg vs 4 mmHg, P<0.01), while the left ventricular systolic pressure was lower (118 mmHg vs 130 mmHg, P=0.02) in the CHF group when compared to the control. Pearson’s correlation coefficient showed a negative association between pulmonary edema and Crs (r=–0.70, P=0.0001) and between pulmonary edema and TLC (r=–0.67, P=0.0034). Pulmonary edema correlated positively with Gti (r=0.68, P=0.001) and Hti (r=0.68, P=0.001). Finally, there was a strong positive relationship between pulmonary edema and heart weight (r=0.80, P=0.001). Conclusion Rats with CHF present important changes in hemodynamic and respiratory mechanics, which may be associated with alterations in cardiopulmonary interactions.

OBJECTIVE: The aim of the present study was to compare the effects of continuous versus interval aerobic exercise training on hemodynamic parameters, cardiac remodeling, and maximal exercise capacity (MEC) in chronic heart failure (CHF) rats.METHOD: Twenty-four male Wistar rats were subjected to myocardial infarction (MI) surgery. Five weeks post MI, the animals were assigned to one of three groups: sedentary group (CHF-Sed, n=8), aerobic continuous training group (CHF-ACT, n=8), and aerobic interval training group (CHF-AIT, n=8). Treadmill training was performed five times a week for 8 weeks (ACT: 50 min/day at 15 m/min and AIT: 40 min/day with 8 min of warm-up at 10 m/min and exercise at 15 m/min 4×4 min interspersed with 4×4 min at 23 m/min). MEC was evaluated pre and post exercise program.RESULTS: Left ventricular end-diastolic pressure (LVEDP), left ventricular mass/body mass ratio (LVM:BM), and total collagen volume fraction were lower in the trained groups compared with the sedentary group, but no difference was found between the trained groups. Systolic ventricular pressure (SVP) and maximum positive derivative of LV pressure (+dP/dtmax) were higher in the trained groups, but CHF-ACT showed higher +dP/dtmax compared to CHF-AIT. Both training regimens were able to increase MEC. However, the aerobic interval training was superior for improving MEC.CONCLUSION: Aerobic training is an important intervention to improve cardiac function and remodeling and physical capacity in CHF rats. Interval training is a potential strategy to maximize the results, but exercise type and intensity are still topics to be explored.

OBJECTIVE: The aim of the present study was to evaluate the effect of 8 weeks of aerobic exercise training on cardiac functioning and remodeling and on the plasma levels of inflammatory cytokines in chronic heart failure rats. METHODS: Wistar rats were subjected to myocardial infarction or sham surgery and assigned to 4 groups: chronic heart failure trained (n = 7), chronic heart failure sedentary (n = 6), sham trained (n = 8) and sham sedentary (n = 8). Four weeks after the surgical procedures, the rats were subjected to aerobic training in the form of treadmill running (50 min/day, 5 times per week, 16 m/min). At the end of 8 weeks, the rats were placed under anesthesia, the hemodynamic variables were recorded and blood samples were collected. Cardiac hypertrophy was evaluated using the left ventricular weight/body weight ratio, and the collagen volume fraction was assessed using histology. RESULTS: The chronic heart failure trained group showed a reduction in left ventricular end-diastolic pressure, a lower left ventricular weight/body weight ratio and a lower collagen volume fraction compared with the chronic heart failure sedentary group. In addition, exercise training reduced the plasma levels of TNF-α and IL-6 and increased the plasma level of IL-10. CONCLUSION: An 8-week aerobic exercise training program improved the inflammatory profile and cardiac function and attenuated cardiac remodeling in chronic heart failure rats.