Search

Context: Bridge exercises are extensively used in trunk-strengthening programs. The aim of this study was to investigate the effect of bridging duration on lateral abdominal muscle thickness and gluteus maximus activation. Design: Cross-sectional. Methods: Twenty-five young males participated in this study. Transversus abdominal (TrA), external and internal oblique ultrasound thickness, gluteus maximus electromyographic activation, and sacral tilt angle were simultaneously measured for every second during 30-second bridging exercise. The contraction thickness ratio and root mean squared signal (normalized to maximum isometric contraction signal) during 6 exercise durations (from 0 to 5, 10, 15, 20, 25, and 30 s) were also calculated and compared using analysis of variance designs. Results: TrA and internal oblique contraction thickness ratio and gluteus maximus root mean squared increased during the first 8 to 10 seconds and remained elevated until the end of the 30-second exercise (P <.05). External oblique contraction thickness ratio declined during exercise (P <.05). Five-second bridging showed less TrA thickness and anteroposterior and mediolateral sacral tilt angle and a lower anteroposterior tilt variability compared with bridges, which lasted more than 10 seconds (P <.05). Conclusions: Bridge exercises longer than 10 seconds may be better for promoting TrA recruitment than bridges of shorter duration. Clinicians and exercise specialists could adjust the duration of bridge exercise based on the aims of the exercise program. [ABSTRACT FROM AUTHOR]

High intensity exercise can lead to depletion of CO2 from the body (hypocapnia). This disturbance becomes more noticeable during recovery or between seasons of intermittent exercise, putting the subject in a neural fatigue state. Objectives: A possible hypothesis to address this condition would be to provide high CO2 mixtures (hypercapnic) during the recovery period from exercise in order to relieve hypocapnia. Methods: Eight men (23.8 ± 1.2 yrs, VO2max = 45 ± 1.9 ml▪kg-1▪min-1) performed cycling exercise at 80%VO2max for 6-7 min. During recovery (23 min) they inhaled hypercapnic air (EXP-21%O2, 3%CO2, and 76%N2) or normal air (CON-21%O2, 0.003%CO2, and 79%N2). Respiratory parameters were collected with open spirometry and heart rate was measured. Results: Exercise caused mild hypocapnia {9.9 mmHg drop of CO2 end-expiratory partial pressure (PETCO2)} in CON condition after exercise (p < .005). PETCO2 elevated close to the rest values during the three hypercapnic phases in EXP condition (main effect of condition p < .001 between EXP and CON), but after hypercapnic breathing it returned to hypocapnia similarly with CON. The ventilatory response (VE▪PETCO2-1) and the exhaled volume of CO2 (VCO2) progressively increased during and also after ventilatory manipulations in EXP compared to CON condition (VE▪PETCO2-1: post hoc p < .001, VCO2: pVCO2: p < .05-.001), and VO2 became lower after the end of second hypercapnic manipulation (p < .05 between EXP and CON). Conclusion: It seems that hypercapnic breathing after exercise is not a good strategy to reverse exercise hypocapnia, because of great hyperventilation caused by CO2 and exercise mechanisms during the recovery period leading to increased CO2 removal from body. This intervention may also decrease O2 supply and muscles blood flow. [ABSTRACT FROM AUTHOR]

High intensity exercise can lead to depletion of CO 2 from the body (hypocapnia). This disturbance becomes more noticeable during recovery or between seasons of intermittent exercise, putting the subject in a neural fatigue state. Objectives : A possible hypothesis to address this condition would be to provide high CO 2 mixtures (hypercapnic) during the recovery period from exercise in order to relieve hypocapnia. Methods : Eight men (23.8 ± 1.2 yrs, VO 2max = 45 ± 1.9 ml▪kg-1▪min-1) performed cycling exercise at 80%VO 2max for 6-7 min. During recovery (23 min) they inhaled hypercapnic air (EXP-21%O2, 3%CO 2 , and 76%N 2 ) or normal air (CON-21%O 2 , 0.003%CO 2 , and 79%N 2 ). Respiratory parameters were collected with open spirometry and heart rate was measured. Results : Exercise caused mild hypocapnia {9.9 mmHg drop of CO 2 end-expiratory partial pressure (P ET CO 2 )} in CON condition after exercise ( p < .005). P ET CO 2 elevated close to the rest values during the three hypercapnic phases in EXP condition (main effect of condition p < .001 between EXP and CON), but after hypercapnic breathing it returned to hypocapnia similarly with CON. The ventilatory response (V E ▪P ET CO 2 -1 ) and the exhaled volume of CO 2 (VCO 2 ) progressively increased during and also after ventilatory manipulations in EXP compared to CON condition (V E ▪P ET CO 2 -1 : post hoc p < .001, VCO 2 : p VCO 2 : p < .05-.001), and VO 2 became lower after the end of second hypercapnic manipulation ( p < .05 between EXP and CON). Conclusion : It seems that hypercapnic breathing after exercise is not a good strategy to reverse exercise hypocapnia, because of great hyperventilation caused by CO 2 and exercise mechanisms during the recovery period leading to increased CO 2 removal from body. This intervention may also decrease O 2 supply and muscles blood flow.