High-velocity elastic-band training improves hamstring muscle activation and strength in basketball players.

BACKGROUND:The aim of this study was use surface EMG activity to assess changes in co- activation of knee flexors and extensors muscle groups during elastic-band exercise after 5 weeks of high-velocity elastic-band training in basketball players. METHODS:College male basketball players (n = 18) were randomly divided into one of two groups: (1) The elastic-band training group performed low-load and high-velocity - lying prone - hamstring curls training three times per week; (2) The control group did not do any training. Pre- and post- training assessment included concentric knee extension and flexion at 60°/s and 240°/s, and the frequency of knee flexion and extension with elastic bands in the prone position. The EMG of the rectus femoris, semitendinosus muscles and the long head of the biceps femoris were assessed during these activities, and 30-m sprint running speed was measured from a stationary start and a running start. RESULTS:It was shown that high-velocity elastic-band training was 1) feasible, 2) increased movement velocity and 3) muscle strength, 4) altered neural control such that excessive lengthening of the hamstring muscle, and hence strain-injuries, may be prevented and 5) improved sprint performance in basketball players. CONCLUSIONS:In addition, these results suggest that high-velocity elastic-band training may be a tool to prevent hamstring strain-injuries in basketball players

Human alpha-actinin-3 genotype association with exercise-induced muscle damage and the repeated-bout effect

Alpha-actinin-3 (ACTN3) is an integral part of the Z line of the sarcomere. The ACTN3 R577X (rs1815739) polymorphism determines the presence or absence of functional ACTN3, which may influence the extent of exercise-induced muscle damage. This study aimed to compare the impact of, and recovery from, muscle-damaging eccentric exercise on subjects with or without functional ACTN3. Seventeen young men (20-33 years old), homozygous for the R (n = 9) or X (n = 8) alleles, performed two bouts of stretch-shortening exercise (50 drop jumps) two weeks apart. Muscle soreness, plasma creatine kinase (CK) activity, jump height, maximal voluntary isometric torque (MVC), peak concentric isokinetic torque (IT), and electrically stimulated knee extension torques at 20 and 100 Hz were measured at baseline and at a number of time points up to 14 days after each bout. There were no significant baseline differences between the groups. However, significant time point × genotype interactions were observed for MVC (p = 0.021) and IT (p = 0.011) for the immediate effect of eccentric exercise in bout 1. The RR group showed greater voluntary force decrements (RR vs. XX: MVC, -33.3% vs. -24.5%; IT, -35.9% vs. -23.2%) and slower recovery. A repeated-bout effect was clearly observed, but there were no differences by genotype group. The ACTN3 genotype modulates the response of muscle function to plyometric jumping exercise, although the differences are modest. The ACTN3 genotype does not influence the clearly observed repeated-bout effect; however, XX homozygotes recover baseline voluntary torque values faster and thus may be able to undertake more frequent training sessions

The effects of high-velocity hamstring muscle training on injury prevention in football players

Background: Explosive and fast body movements, sprints, jumps and quick changes of direction, which are characteristic of the football training, place considerable strain on the hamstring muscles. Due to the high occurrence of hamstring injuries, new preventive strategies are required that focus on high-velocity training. The purpose was to assess the effectiveness of high-velocity elastic-band training in reducing the occurrence of hamstring injuries in football players.Methods: Male football players from 15 teams (n = 319) playing in national competitions participated in this study. The players were involved in a 5-week exercise period in either the intervention group (INT) or the control group (CON), with a follow-up period of ∼4 months where hamstring injuries and exposure time were recorded. The INT group had two to three sessions per week of elastic-band training with low-load, high-velocity leg curls while lying prone; the CON group performed self-paced football-specific drills.Results: The incidence rate of hamstring injuries was 6.5% in the INT group (8 out of 123 players) and 9.2% in the CON group (18 out of 196 players). Although the INT group showed almost 1/3 reduction in hamstring injury incidence compared to the CON group, the difference was not statistically significant (p > 0.05). Moreover, no differences (p > 0.05, odds ratio [OR] = trivial-to-small) in distribution between the groups were found in hamstring injury characteristics (leg dominance and mechanism) except for the distribution of injuries that occurred during matches or training (p = 0.036; OR = 6.14, moderate).Conclusion: The program of high-velocity elastic-band training did not prove to be effective in preventing hamstring muscle injuries in football players despite displaying some positive indications that could be considering when creating injury prevention programs

Lesions in the legs do not preclude ultra-marathon running for 100 days without pain: case report

There is an increasing interest in participation in ultra-endurance events and a concomitant need to understand their effects on health. The effects of extremely prolonged running on leg joints, ligaments, tendons and menisci have not been explored sufficiently. The aim of the present single case study was to use ultrasonography to estimate the effects of a self- paced 8-10 hours daily running for 100 days on the morphology of joints in an experienced 47-year-old ultra-marathon runner. Examination before the start of the 100 days of running revealed already multiple but mostly mild, painless lesions in different joints of both legs. The presence of these lesions did not significantly exacerbate or cause pain during the racing. Iliotibial band bursitis and Achilles paratenonitis were however aggravated, and mild semitendinosus bursitis was a novel finding during the examination after running 8000 km in 100 days. These results are impressive because preparation for this 8000 km running was only ~5 weekly hours of training. In conclusion, this runner displayed multiple lesions in the leg joints at the start but was able to increase running volume by ~10-fold for >100 consecutive days without significantly exacerbating the pre-existing skeletomuscular abnormalities or inducing pain

Lesions in the legs do not preclude ultra-marathon running for 100 days without pain: case report

There is an increasing interest in participation in ultra-endurance events and a concomitant need to understand their effects on health. The effects of extremely prolonged running on leg joints, ligaments, tendons and menisci have not been explored sufficiently. The aim of the present single case study was to use ultrasonography to estimate the effects of a self- paced 8-10 hours daily running for 100 days on the morphology of joints in an experienced 47-year-old ultra-marathon runner. Examination before the start of the 100 days of running revealed already multiple but mostly mild, painless lesions in different joints of both legs. The presence of these lesions did not significantly exacerbate or cause pain during the racing. Iliotibial band bursitis and Achilles paratenonitis were however aggravated, and mild semitendinosus bursitis was a novel finding during the examination after running 8000 km in 100 days. These results are impressive because preparation for this 8000 km running was only ~5 weekly hours of training. In conclusion, this runner displayed multiple lesions in the leg joints at the start but was able to increase running volume by ~10-fold for >100 consecutive days without significantly exacerbating the pre-existing skeletomuscular abnormalities or inducing pain

Recreational 3 × 3 basketball elicits higher heart rate, enjoyment, and physical activity intensities but lower blood lactate and perceived exertion compared to HIIT in active young adults

This study aimed to assess and compare the physiological [percentage of maximal heart rate (%HRmax), blood lactate (BLa), creatine kinase (CK)], hormonal (testosterone, cortisol), psychological [rating of perceived exertion (RPE), enjoyment] and physical [percentage of moderate-to-vigorous physical activity (%MVPA) and vigorous activity (%VA)] responses of recreational 3×3 basketball (3×3BB) and high-intensity interval training (HIIT) in active young adults. Twelve apparently healthy male recreational basketball players (age: 23±3 years; body mass: 82±15 kg; stature: 188±15 cm) completed a 3×3BB match and HIIT with similar duration. %HRmax, %MVPA and %VA were monitored during the protocols, while BLa, cortisol, and testosterone were measured before and after each protocol. CK was measured before the protocols and at 24 h, while RPE and enjoyment were assessed at the end of each protocol. 3×3BB elicited higher %HRmax (p 0.05). 3×3BB elicits higher %HRmax, enjoyment, and physical activity intensities but lower BLa and RPE compared to HIIT in active young adults and might be considered as a potentially suitable activity to increase participants’ health status

Effects of high velocity elastic band versus heavy resistance training on hamstring strength, activation, and sprint running performance

Hamstring muscle injuries occur during high-speed activities, which suggests that muscular strength at high velocities may be more important than maximal strength. This study examined hamstring adaptations to training for maximal strength and for strength at high velocities. Physically active men (n = 25; age, 23.0 +/- 3.2 years) were randomly divided into: (1) a resistance training (RT, n = 8) group, which performed high-load, low-velocity concentric-eccentric hamstring contractions; (2) a resistance training concentric (RTC; n = 9) group, which performed high-load, low-velocity concentric-only hamstring contractions; and (3) a high-velocity elastic band training (HVT, n = 8) group, which performed low-load, high-velocity concentrice-ccentric hamstring contractions. Pre-and posttraining tests included hamstring strength on a hamstring-curl apparatus, concentric knee extension-flexion at 60 degrees/s, 240 degrees/s, and 450 degrees/s, eccentric knee flexion at 60 degrees/s and 240 degrees degrees/s, hamstring and quadriceps coactivation, knee flexion and extension frequency in the prone position, and 30-m sprint running speed from a stationary start and with a running start. Knee flexor torque increased significantly by 21.1% +/- 8.1% in the RTC group and 16.2% +/- 4.2% in the RT group (p < 0.05 for both groups). Hamstring coactivation decreased significantly in both groups. In the HVT group, knee flexion and extension frequency increased by 17.8% +/- 8.2%, concentric peak torque of the knee flexors at 450 degrees/s increased by 31.0% +/- 12.0%, hamstring coactivation decreased, and running performance over 30 m improved (p < 0.05 for all parameters). These findings suggest that resistance training at high velocities is superior to traditional heavy resistance training for increasing knee flexor strength at high velocities, movement frequency, and sprint running performance. These findings also indicate that [...]

Effects of High Velocity Elastic Band versus Heavy Resistance Training on Hamstring Strength, Activation, and Sprint Running Performance

Hamstring muscle injuries occur during high-speed activities, which suggests that muscular strength at high velocities may be more important than maximal strength. This study examined hamstring adaptations to training for maximal strength and for strength at high velocities. Physically active men (n = 25; age, 23.0 ± 3.2 years) were randomly divided into: (1) a resistance training (RT, n = 8) group, which performed high-load, low-velocity concentric–eccentric hamstring contractions; (2) a resistance training concentric (RTC; n = 9) group, which performed high-load, low-velocity concentric-only hamstring contractions; and (3) a high-velocity elastic band training (HVT, n = 8) group, which performed low-load, high-velocity concentric–eccentric hamstring contractions. Pre- and posttraining tests included hamstring strength on a hamstring-curl apparatus, concentric knee extension–flexion at 60°/s, 240°/s, and 450°/s, eccentric knee flexion at 60°/s and 240°/s, hamstring and quadriceps coactivation, knee flexion and extension frequency in the prone position, and 30-m sprint running speed from a stationary start and with a running start. Knee flexor torque increased significantly by 21.1% ± 8.1% in the RTC group and 16.2% ± 4.2% in the RT group (p < 0.05 for both groups). Hamstring coactivation decreased significantly in both groups. In the HVT group, knee flexion and extension frequency increased by 17.8% ± 8.2%, concentric peak torque of the knee flexors at 450°/s increased by 31.0% ± 12.0%, hamstring coactivation decreased, and running performance over 30 m improved (p < 0.05 for all parameters). These findings suggest that resistance training at high velocities is superior to traditional heavy resistance training for increasing knee flexor strength at high velocities, movement frequency, and sprint running performance. These findings also indicate that traditional training approaches are effective for increasing knee flexor strength and reducing knee extensor coactivation, but this outcome is limited to low and moderate speeds

Effects of high velocity elastic band versus heavy resistance training on hamstring strength, activation, and sprint running performance

Hamstring muscle injuries occur during high-speed activities, which suggests that muscular strength at high velocities may be more important than maximal strength. This study examined hamstring adaptations to training for maximal strength and for strength at high velocities. Physically active men (n = 25; age, 23.0 +/- 3.2 years) were randomly divided into: (1) a resistance training (RT, n = 8) group, which performed high-load, low-velocity concentric-eccentric hamstring contractions; (2) a resistance training concentric (RTC; n = 9) group, which performed high-load, low-velocity concentric-only hamstring contractions; and (3) a high-velocity elastic band training (HVT, n = 8) group, which performed low-load, high-velocity concentrice-ccentric hamstring contractions. Pre-and posttraining tests included hamstring strength on a hamstring-curl apparatus, concentric knee extension-flexion at 60 degrees/s, 240 degrees/s, and 450 degrees/s, eccentric knee flexion at 60 degrees/s and 240 degrees degrees/s, hamstring and quadriceps coactivation, knee flexion and extension frequency in the prone position, and 30-m sprint running speed from a stationary start and with a running start. Knee flexor torque increased significantly by 21.1% +/- 8.1% in the RTC group and 16.2% +/- 4.2% in the RT group (p < 0.05 for both groups). Hamstring coactivation decreased significantly in both groups. In the HVT group, knee flexion and extension frequency increased by 17.8% +/- 8.2%, concentric peak torque of the knee flexors at 450 degrees/s increased by 31.0% +/- 12.0%, hamstring coactivation decreased, and running performance over 30 m improved (p < 0.05 for all parameters). These findings suggest that resistance training at high velocities is superior to traditional heavy resistance training for increasing knee flexor strength at high velocities, movement frequency, and sprint running performance. These findings also indicate that [...]

Response to three weeks of sprint interval training cannot be explained by the exertional level

Background and Objectives: The all-out mode of sprint interval training (SIT) has been shown to be an efficient method for improving sports performance, exercise capacity, and aerobic fitness. Although the benefits of SIT are well described, the mechanisms underlying the different degrees of response remain largely unexplored. We aimed to assess the effects of exertion on the responsiveness to SIT. Materials and Methods: The participants were 28 young untrained men (mean ± SD age 25.7 ± 6.03 years) who exhibited either a large or small increase in Wingate test average power in response to nine SIT sessions performed over three weeks. Each training session comprised four-six bouts of 30 s all-out cycling interspaced with 4 min of rest. Individual responses were assessed using heart rate (HR) during exercise for all nine sessions, as well as blood lactate concentration up to 1 h, and the decrement in maximal voluntary knee extension torque (MVC) up to 24 h after the first and last training sessions. Peak oxygen uptake (VO2peak) and maximum HR were measured before and after training during an incremental cycling test to exhaustion. Results: Although all participants showed benefits of SIT such as increased VO2peak, the increase in anaerobic cycling power varied between participants. We identified 17 high responders and nine low responders, whose average power outputs were 0.80 ± 0.22 and 0.22 ± 0.19 W/kg, respectively. The HR achieved during any of the training sessions did not differ between high and low responders. The lactate kinetics did not differ between groups before and after the intervention. Training resulted in a more rapid recovery of MVC without any discernible differences between the high and low responders. Conclusion: The differences in the responses to SIT are not dependent on the exertion level during training