Eduardo D.S. Freitas

The effects of water-based exercise in combination with blood flow restriction on strength and functional capacity in post-menopausal women

Water-based exercise and low-intensity exercise in combination with blood flow restriction (BFR) are two methods that have independently been shown to improve muscle strength in those of advancing age. The objective of this study was to assess the long-term effect of water-based exercise in combination with BFR on maximum dynamic strength and functional capacity in post-menopausal women. Twenty-eight women underwent an 8-week water-based exercise program. The participants were randomly allocated to one of the three groups: (a) water exercise only, (b) water exercise + BFR, or (c) a non-exercise control group. Functional capacity (chair stand test, timed up and go test, gait speed, and dynamic balance) and strength testing were tested before and after the 8-week aquatic exercise program. The main findings were as follows: (1) water-based exercise in combination with BFR significantly increased the lower limb maximum strength which was not observed with water-based exercise alone and (2) water-based exercise, regardless of the application of BFR, increased functional performance measured by the timed up and go test over a control group. Although we used a healthy population in the current study, these findings may have important implications for those who may be contraindicated to using traditional resistance exercise. Future research should explore this promising modality in these clinical populations.

Effects of Different Conditioning Activities on 100-m Dash Performance in High School Track and Field Athletes

This study compared the effects of different conditioning activities on the 100-m dash performance of 11 male, high school track and field athletes (mean age = 16.3; SD = 1.2 years). Participants performed a 100-m dash seven minutes after each of four randomized conditioning protocols, with each condition and 100-m dash separated by 3–10 days. The conditioning protocols were (a) control, no conditioning activity; (b) weighted plyometric, three sets of 10 repetitions of alternate leg bounding with additional load of 10% of the body mass; (c) free sprint, two 20-m sprints; and (d) resisted sprint (RS), two 20-m resisted sprints using an elastic tubing tool. We obtained session ratings of perceived exertion (SRPE) immediately after each conditioning protocol. There were no significant differences between any of the three experimental conditioning activities on 100-m sprint time, but the RS protocol improved 100-m sprint time compared with the control (no conditioning) protocol (p < .001). The RS also led to greater sprint velocity and higher SRPE compared with the control condition (p < .01). There was no significant association between SRPE and 100-m performance (p = .77, r = .05). These results suggest a benefit for young male track and field athletes to the elastic tubing warm-up activities prior to the 100-m dash.

Obstructive sleep apnea does not impair cardiorespiratory responses to progressive exercise performed until exhaustion in hypertensive elderly (vol 22, pg 431, 2018)

The original version of this article was published online containing two items that require correction, namely the abstract (Results section) and Table 3.

Comparing the Acute Effects of Intermittent and Continuous Whole-Body Vibration Exposure on Neuromuscular and Functional Measures in Sarcopenia and Nonsarcopenic Elderly Women

This investigation examined the acute effects of continuous whole-body vibration (CWBV) and intermittent whole-body vibration (IWBV) on neuromuscular and functional measures in women with sarcopenia and nonsarcopenic women. Continuous whole-body vibration was one 6-minute exposure, while IWBV consisted of six 60-second exposures to rest intervals (30 Hz, 2-4 mm amplitude). Factorial analyses revealed group × exposure × time interactions for jump height (JH; F = 10.8, P = .002), grip strength (GS; F = 15.5, P < .001), timed up and go test (F = 11.7, P = .002), and sit and reach test (S&R; F = 9.7, P = .004). Both JH and GS significantly improved post-WBV in women with sarcopenia (P < .001), with post-IWBV significantly greater (P < .001) than post-CWBV. Timed up and go test and S&R significantly improved post-IWBV in both the groups (P < .001) with post-IWBV significantly better than post-CWBV (P < .001). Bench press power at 20% one repetition maximum (1RM) revealed an exposure × time interaction (F = 4.6, P = .04) illuminating that IWBV significantly improved muscular power (P < .001). Bench press power at 40% 1RM revealed group × exposure (F = 6.4, P = .016) and exposure × time interactions (F = 5.8, P = .022). Individuals with sarcopenia significantly increased power output (P < .001) post-IWBV which was significantly greater than post-CWBV (P = .037). Bench press power at 60% 1RM revealed an exposure × time interaction (F = 8.6, P = .006), indicating that power was significantly improved post-IWBV (P = .027) and decreased post-CWBV. Berg Balance scale revealed a time main effect (F = 6.64, P = .015), and pain discomfort was significantly lower post-IWBV. These data indicate IWBV may provide a more efficacious exposure pattern in older women when compared to CWBV.

Time Course Change in Muscle Swelling: High-Intensity vs. Blood Flow Restriction Exercise

This study determined the time course for changes in muscle swelling and plasma volume following high (HI) and low-intensity resistance exercise with blood-flow restriction (LI-BFR). Ten male participants (22.1±3.0 yrs) completed three experimental conditions: high-intensity exercise (HI - 80% of 1RM), low-intensity exercise with BFR (LI-BFR -20% of 1RM, and 160 mmHg of BFR), and control (CON - no exercise or BFR). Muscle cross-sectional area (mCSA), muscle thickness, thigh circumference, and percentage change in plasma volume (PV%∆) were measured. mCSA was significantly greater than rest values at 15 min post-exercise (p<0.01) for HI and LI-BFR, and at 75 min post-exercise (p<0.01) for HI. Muscle thickness was significantly greater than rest immediately post-exercise (p<0.01) and 30 min post-exercise (p<0.01) for HI and LI-BFR, and at 60 min post-exercise for HI (p=0.01). Muscle thickness was greater for BFR immediately post-exercise compared to HI (p=0.01) post-exercise. Thigh circumference was significantly greater from rest at 15 min post-exercise (p=0.01) and at 75 min post-exercise for both LI-BFR (p=0.03) and HI (p<0.01). PV%∆ significantly decreased from rest immediately post-exercise for both HI (p<0.01) and LI-BFR (p<0.01). In conclusion, BFR exercise induces changes in muscle swelling and plasma volume similar to those observed at high-intensities.