BACKGROUND: The back squat is an integral aspect of any resistance training program to improve athletic performance. It is also used for injury prevention of the lower limbs.
OBJECTIVE: The purpose of this study was to examine the effect of back squat training at different intensities on strength and flexibility of the hamstring muscle group (HMG).
METHODS: Twenty-two male recreational bodybuilders with at least two years of experience in resistance training were recruited to participate in a nine-week training program. They were randomly assigned to a heavy back squat group (90-95% of one repetition maximum) or a moderate-intensity back squat group (60-65% of one repetition maximum).
RESULTS: The heavy back squat group resulted in a significantly (p < 0.001) increased in one repetition maximum strength but a significant (p < 0.001) reduction in HMG flexibility when compared to their counterparts. The results of the study indicate that while a heavy back squat training program is effective in improving strength, it has an adverse effect on the flexibility of the HMG.
CONCLUSION: The implication of this study is that there is a tradeoff between strength and flexibility and trainers should select the appropriate training protocols for their athletes to maximize athletic performance.
MATERIALS AND METHODS: This was a pilot prospective, randomized trial of women aged ≥18 years with SUI symptoms who underwent PFMEs at University Malaya Medical Centre from October 2011 to October 2013. The patients were randomly divided into two groups: control (PFMEs alone) and VKD (PFMEs with VKD biofeedback). The patients underwent 16 weeks of pelvic floor training, during which they were assessed using Australian pelvic floor questionnaires and modified Oxford scales for pelvic floor muscle strength at week 0, 4, and 16.
RESULTS: Forty patients were recruited (control 19, VKD 21). Three patients in the control group dropped out during week 16 training, whereas the VKD group had no dropouts. The VKD group reported significantly earlier improvement in SUI scores, as assessed by the Australian pelvic floor questionnaires (P = .035) at week 4. However, there was no significant difference between the groups' SUI scores at week 16. Pelvic floor muscle strength was significantly better in the VKD group at week 4 (P = .025) and week 16 (P = 0.001). The subjective cure rate was similar in both groups at week 16 (62.5% for control and 61.9% for VKD) (P = 0.742).
CONCLUSION: Using the VKD resulted in significant early improvement in SUI scores, and pelvic muscle strength had improved significantly by the end of the study. The VKD proved useful as an adjunct for pelvic floor training.
METHODS: A total of 51 subjects qualified to take part in this quasi-experimental study. They were assigned to either the resistance exercise group (n = 26) or control group (n = 25). The mean age of the 45 participants who completed the program was 70.7 (SD = 6.6). The exercise group met twice per week and performing one to three sets of 8 to 10 repetitions for each of nine lower-limb elastic resistance exercises. All exercises were conducted at low to moderate intensities in sitting or standing positions. The subjects were tested at baseline and 6 and 12 weeks into the program.
RESULTS: The results showed statistically significant improvements in lower-limb muscle strength as measured by five times sit-to-stand test (%Δ = 22.6) and dynamic balance quantified by the timed up-and-go test (%Δ = 18.7), four-square step test (%Δ = 14.67), and step test for the right (%Δ = 18.36) and left (%Δ = 18.80) legs. No significant changes were observed in static balance as measured using the tandem stand test (%Δ = 3.25), and one-leg stand test with eyes opened (%Δ = 9.58) and eyes closed (%Δ = -0.61) after completion of the program.
CONCLUSION: The findings support the feasibility and efficacy of a simple and inexpensive resistance training program to improve lower-limb muscle strength and dynamic balance among the institutionalized older adults.
METHOD: A meta-analysis was conducted to determine the potential impact of isometric exercise on IOP and OPP. The literature on the relationship between isometric resistance exercise and IOP was systematically searched according to the "Cochrane Handbook" in the databases of Pubmed, Web of Science, EBSCO, and Scopus through December 31, 2020. The search terms used were "exercise," "train," "isometric," "intraocular pressure," and "ocular perfusion pressure," and the mean differences of the data were analyzed using the Stata 16.0 software, with a 95% confidence interval.
RESULTS: A total of 13 studies, which included 268 adult participants consisting of 162 men and 106 women, were selected. All the exercise programs that were included were isometric resistance exercises of the lower limbs with intervention times of 1min, 2min, or 6min. The increase in IOP after intervention was as follows: I2=87.1%, P=0.001 using random-effects model combined statistics, SMD=1.03 (0.48, 1.59), and the increase in OPP was as follows: I2=94.5%, P=0.001 using random-effects model combined statistics, SMD=2.94 (1.65, 4.22), with both results showing high heterogeneity.
CONCLUSION: As isometric exercise may cause an increase in IOP and OPP, therefore, people with glaucoma and related high risk should perform isometric exercise with caution.
OBJECTIVES: This study adopts a systematic literature review to (1) examine the effects of resistance training on the performance of adolescent swimmers, and (2) summarize their training methods and intensity.
METHODS: The literature search was undertaken in five international databases: the SCOUPS, PubMed, EBSCOhost (SPORTDiscus), CNKL, Web of Science. The searches covered documents in English and Chinese published until 30th December 2020. Electronic databases using various keywords related to "strength training" and "adolescent swimmers" were searched. Sixteen studies met the inclusion and exclusion criteria where the data was then systematically reviewed using the PRISMA guideline. Furthermore, the physical therapy evidence database (PEDro) scale was used to measure each study's scientific rigor.
RESULTS: This review found that to improve the swimming performance of adolescents, two types of resistance training were used, specifically in water and on land, where both types of training can improve swimming performance. In addition, training with two types of resistance machines were better in the water than with one equipment. Resistance training can improve the swimming performance of adolescent swimmers at 50 m, 100 m, 200 m and 400 m distances. However, most studies only focused on the swimming performance at 50 m and 100 m lengths. A low-intensity, high-speed resistance training programme is recommended for adolescent swimmers to obtain the best training results.
CONCLUSION: Water or land resistance training can improve the swimming performance. Given that both types of exercises have their strengths and weaknesses, combining these methods may enhance the swimmers' performance. In addition, despite the starting and turning phases consuming up to one-third of the total swimming time for short distances, literature in this area is limited.
SYSTEMATIC REVIEW REGISTRATION: https://www.crd.york.ac.uk/prospero, identifier: CRD42021231510.