Regular exercise participation has been known to lower blood pressure for decades. However, despite the positive hemodynamics and adaptations that see changes in the cardiovascular system and encouraging outcomes, there are controversies around the effects of the different exercise intensities on blood pressure (BP). We do not fully understand which intensity would be more suitable for persons with hypertension (HTN), specifically if they have been sedentary for a long time. The intensity undertaken to exercise is often overlooked and might contribute to poor exercise adherence. Few studies have conducted a large sample of minorities to understand how different exercise intensity affects their BP recovery. Minority populations like African Americans are underrepresented in clinical studies despite experiencing more HTN and participating less in physical activity. Non-compliance to exercise with African Americans could contribute to the exercise intensity, specifically for newer exercisers.
The systematic review aimed to explore studies that examined post-exercise BP response in African American adults and highlight the different exercise intensities and modes. The aim of this study was to investigate and determine which exercise intensity could produce the most optimal results for BP control in African Americans.
A systematic literature search was carried out with two databases from 2000 to 2010, searching for relevant manuscripts related to exercise involvement with African Americans. The age was limited to 19 years and older, with geographic location restricted to studies from the United States, given the population reviewed. The exercise mode could include outdoor walking with a pedometer device, treadmill walking/jogging, cycling or stationary cycling, weight training, aerobic exercise, or low to high workload.
Two hundred and seventy-nine articles we found, with 270 excluded. In total, nine papers met the inclusion criteria and were analysed. Seven papers saw significant outcomes in BP, with two not reporting meaningful differences from baseline to post-exercise. The most common exercise mode was walking at moderate intensity, specifically among female participants.
The review found low to moderate or moderate intensity was favourable to reducing post-exercise BP in African Americans. The outcomes have implications in prescribing exercise interventions where the intensity or mode of training can be altered, expanding the beneficial effects of exercise on BP.
This longitudinal study investigated the potential enhancement of one physical and nine performance variables of New Zealand Rugby-Otago Rugby Football Union Academy college-age women student-athletes (NZORFUSA) using in-person- and non-video online-training (online) supervision.
Recruited NZORFUSA followed a periodised training protocols over 70-weeks. During weeks 1–35 and weeks 53–70 (in-season), the NZORFUSA received 25-h of in-person supervision, participated in 15-h of team practice and game play each week. Over weeks 36–52 (off-season), due to the NZORFUSA returning home over the college summer break, NZORFUSA received online supervision. Performance assessments occurred on weeks 1, 31, 53 and 70. During each testing session, body weight, acceleration, anaerobic endurance, lower-body power, speed, and upper-body strength performance data were collected. Data from weeks 1–70 are presented in this paper; weeks 1–31 and 1–53 data were previously published.
Over 70-weeks of in-person-, online-, and again in-person supervision, mean data showed a decrease in body weight [effect size, Cohen's d = 0.12, trivial; 95% confidence interval (CI): 29.4–127.7] and showed improvements in performance variables (large effect size, d = 1.49–4.33), including lower-body power (CI: 39.9–47.5), upper-body bench press strength (CI: 29.7–132.3) and anaerobic endurance; for the latter performance variable, to complete the 40 m repeat sprints needs less effort (CI: 81.3–95.5) with concurrent lower fatigue level being achieved (CI: 8.08–9.77).
Physical and performance enhancement for Academy women student-athletes with in-person, online, and again in-person supervision over 70-weeks is attainable. Future longitudinal research is needed to assist performance enhancement for this cohort.
The purpose of the study was to investigate (a) the effects of two priming training methods (repeated-sprint and ballistic-power) on speed, power and agility performance in well-trained soccer players, and (b) whether stronger players may have greater benefits on performance from the priming sessions compared to their weaker counterparts.
Fourteen (n = 14) male well-trained soccer players (age: 21.1 ± 3.3 years, height 1.77 ± 0.07 m, mass: 73.2 ± 8.5 kg) were randomly assigned to perform a repeated-sprint and a ballistic-power priming training session applied 24 h prior to a countermovement jump (CMJ), a 20 m sprint and a T-Test agility time-trials. Rating of perceived exertion (RPE) was also evaluated following the repeated-sprint and the ballistic-power priming programs. On a different day, body composition, leg extension isometric peak torque (IPT) and rate of torque development (RTD) were evaluated. Soccer players were also divided into stronger and weaker groups according to their IPT relative to body mass.
Agility T-Test time-trial decreased significantly by − 2.51% ± 2.28% (P = 0.005) and − 1.91% ± 2.30% (P = 0.02) following repeated-sprint and ballistic-power priming respectively, compared to control (C) condition. RPE, CMJ and 20 m sprint performance were not different between the priming sessions (P > 0.05). Stronger players decreased only T-Test agility time-trial by − 3.02% ± 2.96% (P = 0.016), after repeated-sprint and by − 2.64% ± 2.76% (P = 0.020) following ballistic-power priming when compared with C condition. However, no differences were observed between stronger and weaker players (P > 0.05).
These results suggest that both repeated-sprint and ballistic-power priming training methods, when applied 24 h prior to a soccer game, may enhance agility performance in well-trained soccer players.
To investigate knee joint function during an unanticipated cutting task between healthy and ACL-reconstructed (ACL-R) females within the same NCAA Division I collegiate female lacrosse team (WLAX) via knee mechanics and estimated vasti and hamstring muscle forces.
Knee mechanics during three unanticipated cutting trials were observed using 3D motion analysis techniques for 26 healthy female lacrosse players, five which had previous history of ACL-R. Knee flexion angle and knee extensor moment were calculated via Visual3D. Modified musculoskeletal models were used to estimated vasti and hamstrings muscle forces obtained from static optimization. The 2 × 2 (group × limb) repeated measures ANOVAs were used to identify differences in knee mechanics, and vasti and hamstring muscle groups among healthy/ACL-R between their preferred and involved limbs.
There was an interaction between group and limb for knee extensor moment. ACL-R females had less knee extensor moments in their involved limb compared to their uninvolved limb (P < 0.001). There was also a group main effect found for knee flexion angle. ACL-R females cut with less knee flexion angle compared to healthy females (P < 0.013). No significant differences were found for estimated vasti or hamstring forces.
These pilot results indicate that despite all female WLAX players undergoing the same strength and conditioning programming, training sessions, with the same coaching staff, differences in knee joint mechanics still exist between healthy and ACL-R players. These data should help inform larger-scaled studies investigating the impact of ACL-R on athletes within the same sports team.
Pacing profiles differ substantially in endurance sports with short competition duration (2–4 min). Herein, we investigated the effect of a fast start (FS) versus a conservative start (CS) pacing strategy on sprint time-trial performance in competitive junior cross-country skiers.
Sixteen females (~ 17 years old) performed two individual self-paced 1.4 km time-trials (TT) in free technique on roller skis separated by 40 min of recovery. Skiers were instructed to perform a FS and CS pacing strategy the first ~ 400-m (~ 1 min) in a randomized order. Split and finish time was determined using radio-based photocells, while speed characteristics were collected with GNSS/IMU sensors. 1–10 Rate of perceived exertion (RPE) was collected retrospectively for 3 points during the TT. Based on mean FS and CS performance, skiers were divided into a Low- (n = 8) and High performers (n = 8).
Overall, the FS strategy induced a faster ~ 400-m time (56.0 ± 3.8 s) than CS (58.7 ± 3.4 s) (P < 0.05), but no differences in finish times were found between strategies for the group as a whole (FS: 213.3 ± 12.0 s; CS, 212.9 ± 10.3 s, P = 0.68). However, High performers skied faster with FS than CS (203.4 ± 7.4 s vs. 205.1 ± 7.1 s; 0.8% ± 0.7%, P < 0.05), whereas the Low performers skied faster with CS than FS (220.7 ± 6.1 s vs. 223.1 ± 5.0 s; 1.1% ± 1.0%, P < 0.05). Independent of performance level, summated RPE during the TT was higher with FS versus CS (23 ± 2 vs. 22 ± 2, P < 0.05).
Optimal pacing strategy for TT sprint skiing appears dependent of performance level. A “fast start” strategy was accompanied by higher discomfort during the time-trial.
To explore whether active physical exercise (APE) is more effective than conventional continuous passive motion (CPM) in improving functional knee recovery and quality of life without increasing the risk of complication in patients with endoprosthetic knee replacement for bone tumor.
Six hundred and fourteen patients were enrolled and allocated to either APE or CPM for 6 months. APE was specific for patients with bone tumors on the distal femur (APE-F) and proximal tibia (APE-T), whereas CPM was similar to both types of patients (CPM-F and CPM-T). APE for both APE-F and APE-T patients was started on the second post-operation day, and CPM was initiated on the second post-procedure day in CPM-F patients, and in the seventh post-procedure week in CPM-T patients. The 6-month APE training consisted of three stages with training intensity progressively increasing though limited within a range of metabolic equivalent (MET) on each stage. Training intensity was individualized based on personal basic MET. The patients were followed up for 5 years for regular assessments of functional knee recovery, quality of life, and rate of complications.
APE-F and APE-T patients presented with significantly better results in functional knee recovery and quality of life in comparison with CPM-F and CPM-T patients, respectively. In addition, APE-T patients reached a similar level of quality of life as APE-F patients 6-month post-operation, whereas CPM-T patients reached a similar level of quality of life as CPM-F patients 3 years after the procedure. Nevertheless, APE training did not induce a higher incidence of complications than CPM training.
APE training was more effective in improving functional knee recovery and quality of life without increasing the risk of complications than CPM training, thus, being strongly recommended to the patients for post-operation rehabilitation.
Trial registration: ChiCTR2200061774
This study aimed to (i) provide normative data for measures of physical fitness (PF) (i.e., muscle strength, muscle power, linear sprint speed) in 8- to 14-year-old Tunisian children and (ii) to examine sex and age group differences in these measures.
A total of 597 subjects (aged 8~14）participated in this study, the normative data for handgrip strength, jump height, and linear sprint speed were generated and collected, and the two-way analysis of variance (ANOVA) was used to identify the presence of the main effect of age, sex, an age × sex interaction for all tests.
The two-way ANOVA showed credible age by sex interactions for all measures of PF [Effect Size (ES) ranged from 0.28 to 0.68; P < 0.05]. The findings indicated a main effect of age in handgrip strength, countermovement jump (CMJ) height, and linear sprint speed (all P < 0.05), regardless of sex. Post hoc analyses showed early increases in handgrip strength for boys from 8 to 14 years. For CMJ height, an increase in performance was observed from 10 to 11 years (ES = 0.23) and 12 to 13 years (ES = 0.14) (all P < 0.05). For linear sprint speed, performance enhancement was observed from 10 to 11 years (ES = 1.00). In girls, an increase in handgrip strength was noted from 9 to 12 years (ES = 1.00). However, the changes across age were less convincing for CMJ height and linear sprint speed tests, suggesting that differences for girls were not supported by the collected data. Boys outperformed girls in all measures of PF (P < 0.05). A summary of the estimated centiles of 10- and 30-m sprint speed, grip strength, and CMJ height for boys and girls allows a particular child’s test values to be compared to the norms for the group.
In summary, this study provides normative data that can be used as a tool to classify sprint speed, strength, and jump height performance in children of both sexes aged 8–14 years.
Hamstring strain injuries (HSI) represent a significant burden in soccer. High-speed running is one of the most common HSI mechanism, in particular during match congested periods. Peak force and rate of force development (RFD) of the hamstring muscles tested at long muscle length have shown reductions following fatiguing tasks. However, no study has used a meticulous fatiguing protocol nor reliability scores have been provided. Hamstring peak force, RFD50−100 and RFD100 −150 were assessed at long muscle length in 19 soccer players (26.0 ± 4.1 years) before and after the repeated sprint ability (RSA) test. We aimed to calculate reliability scores for both limbs before and after the fatiguing task, and to compare peak force, RFD50−100 and RFD100−150 following the RSA test to baseline values. Peak force displayed “excellent” reliability scores before and after the RSA test, whereas RFD ICC showed “good” values in both time points, but CV scores were not acceptable (i.e. > 10%). Significant moderate to large decreases were found in peak force (g = − 1.11 to − 0.90), RFD50−100 (g = − 1.37 to − 1.11) and RFD100−150 (g = − 0.84 to − 0.69) in both dominant and non-dominant limbs. Maximal isometric peak force, RFD50−100 and RFD100−150 of the hamstrings tested at long muscle length reduced following the RSA test. However, only peak force displayed “excellent” reliability scores, whereas RFD measures could not be considered acceptable owing to their lower reliability scores. Thus, practitioners can be confident about peak force changes, whilst caution should be used when examining such changes in RFD.