Effects of Cannabidiol Supplementation on Skeletal Muscle Regeneration after Intensive Resistance Training

Cannabidiol supplements (CBD) are increasingly consumed by athletes to improve regeneration. However, the evidence for the pro-regenerative effects of CBD in sports is quite limited. Therefore, our aim was to investigate the effects of a single CBD supplementation in a six-arm placebo-controlled crossover study after resistance training on performance and muscle damage. Before and after the resistance training, one-repetition maximum in the back squat (1RM BS), countermovement jump (CMJ), and blood serum concentrations of creatine kinase (CK) and myoglobin (Myo) were measured in healthy, well-trained participants. 16 out of 21 participants completed the study and were included in the analysis. In 1RM BS, a significant decrease was observed after 24 h (p < 0.01) but not after 48 and 72 h. A significant group difference was detected after 72 h (p < 0.05; ES = 0.371). In CMJ, no significant changes were observed. The CK and Myo concentrations increased significantly after 24 h (CK: p < 0.001; Myo: p < 0.01), 48 h (CK: p < 0.001; Myo: p < 0.01) and 72 h (CK: p < 0.001; Myo: p < 0.001). After 72 h, significant group differences were observed for both muscle damage biomarkers (CK: p < 0.05 ES = 0.24; Myo: p < 0.05; ES = 0.21). The results show small but significant effects on muscle damage and recovery of squat performance after 72 h. However, more data are required for clearer statements concerning potential pro-regenerative effects of CBD supplementation after resistance training.

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Influence of Strength Level on the Acute Post-Activation Performance Enhancement Following Flywheel and Free Weight Resistance Training

Sensors ◽

10.3390/s20247156 ◽

2020 ◽

Vol 20 (24) ◽

pp. 7156

Author(s):

Borja Sañudo ◽

Moisés de Hoyo ◽

G Gregory Haff ◽

Alejandro Muñoz-López

Keyword(s):

Resistance Training ◽

Body Mass ◽

Performance Enhancement ◽

Group Analysis ◽

Sprint Performance ◽

Countermovement Jump ◽

Back Squat ◽

Free Weight ◽

Before And After ◽

Positive Effect

This study aimed to compare the post-activation potentiation performance enhancement (PAPE) response to the acute inertial flywheel (FW) and free weight resistance training (TRA) on subsequent countermovement jump (CMJ) and sprint performance (10 m sprint). This study used a randomized crossover design including twenty-eight healthy males that were divided into strong (relative one-repetition maximum (1RM) back squat > 2.0 × body mass) and weak (relative 1RM back squat < 2.0 × body mass) groups. All participants performed the following: (a) three reps at 90% of their 1RM back squat (TRA) and (b) three reps on an inertial FW (plus one repetition to initiate flywheel movement) with an intensity that generated a mean propulsive velocity equal to that achieved with 90% of the 1RM back squat. Before and after the conditioning activity, participants performed two CMJs and two 10 m sprints. Within-group analyses showed significantly greater CMJ (d > 0.9, p < 0.001) and sprint performance (d > 0.5, p < 0.05) in the FW and the TRA group. Between-group analysis showed that sprint changes were significantly greater in the FW-strong group when compared with the TRA (F1,18 = 5.11, p = 0.036, η2p = 0.221—large) group. These results suggest that using a squat activation protocol on a FW may lead to an acute positive effect on jump and sprint performance, especially in stronger individuals.

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Velocity-based resistance training: impact of velocity loss in the set on neuromuscular performance and hormonal response

Applied Physiology Nutrition and Metabolism ◽

10.1139/apnm-2019-0829 ◽

2020 ◽

Vol 45 (8) ◽

pp. 817-828 ◽

Cited By ~ 1

Author(s):

David Rodríguez-Rosell ◽

Juan Manuel Yáñez-García ◽

Ricardo Mora-Custodio ◽

Fernando Pareja-Blanco ◽

Antonio G. Ravelo-García ◽

...

Keyword(s):

Resistance Training ◽

Training Group ◽

Countermovement Jump ◽

Hormonal Response ◽

Repetition Maximum ◽

Neuromuscular Performance ◽

Before And After ◽

Training Impact ◽

Curvilinear Relationships ◽

Healthy Males

This study aimed to compare the effects of 2 resistance training (RT) programs with different velocity losses (VLs) allowed in each set: 10% (VL10%) versus 30% (VL30%) on neuromuscular performance and hormonal response. Twenty-five young healthy males were randomly assigned into 2 groups: VL10% (n = 12) or VL30% (n = 13). Subjects followed a velocity-based RT program for 8 weeks (2 sessions per week) using only the full-squat (SQ) exercise at 70%–85% 1-repetition maximum (1RM). Repetition velocity was recorded in all training sessions. A 20-m running sprint, countermovement jump (CMJ), 1RM, muscle endurance, and electromyogram (EMG) during SQ exercise and resting hormonal concentrations were assessed before and after the RT program. Both groups showed similar improvements in muscle strength and endurance variables (VL10%: 7.0%–74.8%; VL30%: 4.2%–73.2%). The VL10% resulted in greater percentage increments in CMJ (9.2% vs. 5.4%) and sprint performance (–1.5% vs. 0.4%) than VL30%, despite VL10% performing less than half of the repetitions than VL30% during RT. In addition, only VL10% showed slight increments in EMG variables, whereas no significant changes in resting hormonal concentrations were observed. Therefore, our results suggest that velocity losses in the set as low as 10% are enough to achieve significant improvements in neuromuscular performance, which means greater efficiency during RT. Novelty The VL10% group showed similar or even greater percentage of changes in physical performance compared with VL30%. No significant changes in resting hormonal concentrations were observed for any training group. Curvilinear relationships between percentage VL in the set and changes in strength and CMJ performance were observed.

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Ultrastructural muscle damage in young vs. older men after high-volume, heavy-resistance strength training

Journal of Applied Physiology ◽

10.1152/jappl.1999.86.6.1833 ◽

1999 ◽

Vol 86 (6) ◽

pp. 1833-1840 ◽

Cited By ~ 60

Author(s):

Stephen M. Roth ◽

Gregory F. Martel ◽

Frederick M. Ivey ◽

Jeffrey T. Lemmer ◽

Brian L. Tracy ◽

...

Keyword(s):

Strength Training ◽

Muscle Damage ◽

Vastus Lateralis ◽

High Volume ◽

Older Men ◽

Group Differences ◽

Strength Increase ◽

Significant Group ◽

Leg Extension ◽

Old Men

This study assessed ultrastructural muscle damage in young (20–30 yr old) vs. older (65–75 yr old) men after heavy-resistance strength training (HRST). Seven young and eight older subjects completed 9 wk of unilateral leg extension HRST. Five sets of 5–20 repetitions were performed 3 days/wk with variable resistance designed to subject the muscle to near-maximal loads during every repetition. Biopsies were taken from the vastus lateralis of both legs, and muscle damage was quantified via electron microscopy. Training resulted in a 27% strength increase in both groups ( P < 0.05). In biopsies before training in the trained leg and in all biopsies from untrained leg, 0–3% of muscle fibers exhibited muscle damage in both groups ( P = not significant). After HRST, 7 and 6% of fibers in the trained leg exhibited damage in the young and older men, respectively ( P < 0.05, no significant group differences). Myofibrillar damage was primarily focal, confined to one to two sarcomeres. Young and older men appear to exhibit similar levels of muscle damage at baseline and after chronic HRST.

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Sex and Age-Group Differences in Strength, Jump, Speed, Flexibility, and Endurance Performances of Swedish Elite Gymnasts Competing in TeamGym

Frontiers in Sports and Active Living ◽

10.3389/fspor.2021.653503 ◽

2021 ◽

Vol 3 ◽

Author(s):

Stefan Höög ◽

Erik P. Andersson

Keyword(s):

Performance Metrics ◽

Upper Body ◽

Group Differences ◽

Age Group ◽

Countermovement Jump ◽

Male Athletes ◽

Arm Swing ◽

Back Squat ◽

Forward Bending ◽

Run Test

Purpose: To analyze sex and age group differences in strength, jump, speed, flexibility, and endurance performances of TeamGym athletes.Methods: A total of 91 Swedish elite gymnasts (junior female, n = 26, age = 15.4 y; senior female, n = 23, age = 20.0 y; junior male, n = 19, age = 15.6 y; senior male, n = 23, age = 20.6 y) participated in three testing sessions on three separate days. These were: (1) a series of flexibility tests for the lower- and upper-body; (2) strength tests for the lower- and upper-body; and (3) various types of jumps, a 20-m sprint-run, and a 3,000-m run test.Results: Males were 24% stronger in the back squat one-repetition maximum (relative to body mass) compared to females (P < 0.001, Hg = 1.35). In the pull-ups and dips, 2.4 and 2.3 times more repetitions were completed by the males compared to the females (both P < 0.001, 0.70 ≤ R ≤ 0.77). However, females were similarly strong as males in the hanging sit-ups test (P = 0.724). The males jumped 29, 34, 33, and 17% higher in the squat jump (SJ), countermovement jump (CMJ), countermovement jump with arm swing (CMJa), and drop jump (DJ), respectively, compared to the females (all P ≤ 0.002, 0.14 ≤ ηp2 ≤ 0.60). In the 20-m sprint run, males were 4% faster than females (P < 0.001, R = 0.40). Moreover, the females had significantly better flexibility than the males in the trunk forward bending, front split, and side split tests (all P < 0.001, 0.24 ≤ ηp2 ≤ 0.54). In the 3,000-m run test, males were 11% faster than females (P < 0.001, ηp2 ≤ 0.54). Compared to junior athletes, seniors performed better in the pull-ups, dips, SJ, CMJ, CMJa, and 20-m sprint-run tests (all P ≤ 0.012, 0.31 ≤ R ≤ 0.56, 0.16 ≤ ηp2 ≤ 0.25), with separate within-sex age-group differences (i.e., juniors vs. seniors) that were significant for the males but not for the females in the SJ, CMJ, CMJa, and 20-m sprint-run tests (males: all P < 0.001, 0.67 ≤ R ≤ 0.69, 1.37 ≤ Hg ≤ 2.01; females: all P = 0.298–732).Conclusions: Large sex and age-group differences were observed for most physical performance metrics with specific within-sex age-group differences only observed for male athletes, with male seniors performing better than juniors in the SJ, CMJ, CMJa, and 20-m sprint-run tests.

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Time course of recovery is similar for the back squat, bench press, and deadlift in well-trained males

Applied Physiology Nutrition and Metabolism ◽

10.1139/apnm-2019-0004 ◽

2019 ◽

Vol 44 (10) ◽

pp. 1033-1042 ◽

Cited By ~ 2

Author(s):

Daniel J. Belcher ◽

Colby A. Sousa ◽

Joseph P. Carzoli ◽

Trevor K. Johnson ◽

Eric R. Helms ◽

...

Keyword(s):

Muscle Damage ◽

Time Course ◽

Bench Press ◽

Recovery Period ◽

Time Effect ◽

Back Squat ◽

Before And After ◽

And Performance ◽

Acute Changes ◽

Joint Range

This study examined the time course of recovery following resistance exercise sessions in the back squat, bench press, and deadlift. Twelve well-trained males (age: 24.5 ± 3.8 years, body mass: 84.01 ± 15.44 kg, training age: 7.1 ± 4.2 years) performed 4 sets to failure at 80% of a 1-repetition maximum (1RM) on the squat, bench press, and deadlift in successive weeks. The bench press was always performed in week 2 with the squat and deadlift order counterbalanced between weeks 1 and 3. Indirect muscle damage and performance fatigue was assessed immediately before and after exercise and at 24 h, 48 h, 72 h, and 96 h postexercise. Outcome measures included limb swelling, joint range of motion, delayed onset muscle soreness, average concentric velocity (ACV) at 70% of 1RM, creatine kinase, lactate dehydrogenase, and cell-free DNA (cfDNA). Most measures demonstrated a main time effect (p < 0.05) within conditions; however, no between condition (p > 0.05) differences existed. ACV decreased in the squat condition for up to 72 h (p = 0.02, –8.61%) and in the bench press (p < 0.01, –26.69%) immediately postexercise but did not decline during the deadlift condition (p > 0.05). There was a main time effect for increased cfDNA in the squat (p < 0.01) and bench press (p < 0.05), but not the deadlift (p = 0.153). Further, immediately postexercise increases in cfDNA were directly related (p < 0.05) to changes in ACV in all 3 conditions. These results suggest that the deadlift does not result in greater muscle damage and recovery time than the squat and bench press following volume-type training in well-trained men. Further, acute changes in cfDNA may predict performance during the recovery period.

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Cognitive and psychosocial effects of an acute sun salutation intervention among adults with stress

10.31234/osf.io/7zu3g ◽

2021 ◽

Author(s):

Madhura Phansikar ◽

Sean Patrick Mullen

Keyword(s):

Controlled Trial ◽

Well Being ◽

Moderate Intensity ◽

Psychosocial Effects ◽

Significant Group ◽

Significant Group Difference ◽

Performance Improvements ◽

Randomized Controlled ◽

Yoga Group ◽

Before And After

Evidence suggests that yoga can improve executive functioning (EF) and psychological well-being, but there is no evidence whether flow-based, moderate-intensity forms of yoga can deliver similar benefits. The purpose of this randomized controlled trial was to test the aforementioned effects of engaging in a 30-minute, video-guided sun salutation exercise (n = 25), relative to aerobic exercise (n = 22) and attentional control (n = 24). Low-active participants (Mage = 27.84; 87.3% female) completed psychosocial assessments and tasks assessing EF, before and after the session. Results showed a significant group difference for state anxiety (p = .01, ηp² = .13) and stress (p < .05, ηp² = .09), in favor of the yoga group. No significant between-groups differences in EF were observed. Results suggest that video-guided, flow-based forms of yoga can induce immediate improvements in well-being, yet extended involvement may be required to realize performance improvements in memory and processing speed.

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Speech Development of Children with Cleft Palate before and after Palatal Surgery

The Cleft Palate-Craniofacial Journal ◽

10.1597/1545-1569_2003_040_0019_sdocwc_2.0.co_2 ◽

2003 ◽

Vol 40 (1) ◽

pp. 19-31 ◽

Cited By ~ 15

Author(s):

Courtney E. Jones ◽

Kathy L. Chapman ◽

Mary A. Hardin-Jones

Keyword(s):

Cleft Palate ◽

Speech Production ◽

Educational Level ◽

Speech Development ◽

Group Differences ◽

Significant Group ◽

Before And After ◽

Palate Repair ◽

Palatal Surgery ◽

Over Time

Objective This study examined the speech production abilities of children with cleft palate before and after palate repair. Participants Twenty-eight children participated in the study, 14 with cleft palate and 14 without clefts matched for age, gender, and mothers’ educational level. Main Outcome Measures Comparisons were made between the children with cleft palate before and after surgery for canonical babbling ratios, size of consonant inventories, place and manner characteristics, and early developing sounds [p, b, t, d, k, g, m, n, η]. Also, comparisons were made between the children with cleft palate and their peers without clefts at postsurgery/17 months for the measures described above. Results Paired ttests revealed differences in pre- and postsurgery performance of the children with cleft palate for production of canonical syllables and size of consonant inventories. Although no significant differences were noted for place and manner features, production of oral stops doubled from the time before surgery to that after surgery. Specifically, production of the bilabial stop [b] showed significant change over time. Results of independent t tests indicated no difference between groups for production of canonical syllables and size of consonant inventories at 17 months. However, significant group differences were noted for production of stops, oral stops, nasals, glides, and alveolars. The children without clefts produced more stops, oral stops, and alveolars. In contrast, more nasals and glides were seen in the vocalizations of the children with cleft palate. Conclusions Children with cleft palate made gains in production of canonical syllables and size of consonant inventories postsurgery; however, they continued to show deficits in production of stops and alveolar place features.

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A Comparative Study of Ranchi Labourer Life

International Journal of Indian Psychology ◽

10.25215/0403.036 ◽

2017 ◽

Vol 4 (3) ◽

Author(s):

Saraswati Rani ◽

Thiyam Kiran Singh

Keyword(s):

Life Satisfaction ◽

Demographic Data ◽

Total Sample ◽

Group Differences ◽

Satisfaction Scale ◽

Significant Group ◽

Significant Group Difference ◽

Male And Female ◽

Normal Populations ◽

Significant Difference

Labour is a social class of group comprises of those who do manual labour or work for wages. A thousand of labours every day migrate in Ranchi city and they work whole day at daily wages and back to home in evening. Here we see, there are many people who were well educated (6% male labour) like graduate or post graduate and they were working as a labour only because of lack of job and poor economical conditions. At present scenario money is important for every one’s life so everyone works for money. Labors worked mostly in unorganized sectors at daily wages and their rule is “no work no wages”. Method: A total sample of 87 normal populations (50 male and 37 female labours) were selected using purposive and consecutive based sampling method from the area of Morabadi Ground (Labour Market), Ranchi. Socio demographic data sheet and life satisfaction scale were used to find out significant difference in socio-demography and life satisfaction between male and female. Result- In the socio demographic profile, a significant group differences were found in age, education and Religion in both groups. Again, significant group difference was found in the total score of Life Satisfaction between both sex (male and female labourers) indicating male labourers had better life satisfaction in comparison to the female labourers. Conclusion: Some results showed that labourers (Male & Female) had poor life satisfaction and they are surviving with many problems like – poor education, poor health and dissatisfaction of job. Current finding shows that the male labourers have better life satisfaction in comparison to female labourers.

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Exploring the relationship between mindfulness and rock-climbing: a controlled study

Current Psychology ◽

10.1007/s12144-021-01593-y ◽

2021 ◽

Author(s):

Katherine A. Wheatley

Keyword(s):

Rock Climbing ◽

Controlled Study ◽

Group Differences ◽

Post Intervention ◽

Control Activity ◽

Significant Group ◽

Mixed Anova ◽

Building Activity ◽

Before And After ◽

The Relationship

AbstractMindfulness is a meditative practice that has received increasing attention within positive psychology as an effective tool to increase wellbeing and decrease anxiety. Previous research has demonstrated that rock-climbers have a higher endorsement of mindfulness and life satisfaction than the general population; yet to date, no research has empirically explored the relationship between mindfulness and rock-climbing. In the current study fifty-nine participants ($$ \overline{\mathrm{x}} $$ x ¯ = 20.63, SD = 1.60) were asked to complete measures of mindfulness, wellbeing and anxiety before and after participating in an ‘intervention’. The intervention consisted of a mindfulness activity followed by either indoor bouldering (a form of rock-climbing) versus a physical activity control. A mixed ANOVA revealed that participation in bouldering increased the measure of mindfulness significantly more than the control activity; however, no significant group differences were found for the measures of wellbeing and anxiety. A regression analysis then revealed that group condition accounted for 33% of the variance in post-intervention mindfulness levels when controlling for baseline levels of mindfulness. This is the first study to experimentally demonstrate that engagement with rock-climbing increases mindfulness in young adults. Theoretically, the results have implications for our understanding of “flow” and optimal human experience. Practically, the study highlights the potential to implement rock-climbing as a resilience-building activity and integrate the sport within therapeutic frameworks.

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Effects of a resistance training program on muscular performance adaptations: comparing three vs. four times per week

Biomedical Human Kinetics ◽

10.2478/bhk-2020-0019 ◽

2020 ◽

Vol 12 (1) ◽

pp. 149-156

Author(s):

Hossein Firoozi ◽

Hamid Arazi ◽

Abbas Asadi

Keyword(s):

Resistance Training ◽

Bench Press ◽

Muscle Size ◽

Whole Body ◽

Control Group ◽

Resistance Training Program ◽

Significant Group ◽

Group Time ◽

Before And After ◽

Muscular Adaptations

SummaryStudy aim: The aim of this study was to examine the effects of 8 weeks of resistance training (RT) with three vs. four sessions per week and equated training volume on muscular adaptations in men.Materials and methods: Thirty-three healthy young men volunteered to participate in the study and were randomly assigned to three times per week whole-body RT (RT3, n = 11), four times per week whole-body RT (RT4, n = 11) or a control group (CG, n = 11). Before and after training, participants were evaluated for one-repetition maximum (1RM) and muscular endurance (i.e., 60% of 1RM to failure) for the leg press and bench press. In addition, thigh, arm, chest, and calf circumferences, and percent body fat were assessed before and after training.Results: The findings revealed significant main effects of time for chest and thigh circumferences (p ≤ 0.05). There were no significant group × time interactions for chest and thigh circumferences (p > 0.05), but the RT4 showed greater changes (effect size [ES]: 0.48 vs. 0.15) in chest circumference, while the RT3 showed greater changes (ES: 0.77 vs. 0.35) in thigh circumference. Significant group × time interactions were observed for the 1RM of leg and bench presses (p < 0.05). Post-hoc analyses showed greater improvements for RT3 in comparison to RT4 in 1RM bench press (p = 0.01, ES: 0.77 vs. 0.6) and leg presses (p = 0.009, ES: 0.94 vs. 0.86).Conclusions: These results suggest that RT induces meaningful adaptive effects to improve strength and muscle size in men and RT3 appears to be more effective to induce muscular adaptations.

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