Effects of Six Weeks of Flywheel Single-Leg Romanian Deadlift Training on Speed, Jumping and Change of Direction Performance

Implementing hamstring injury prevention programmes remotely: a randomised proof of concept trial

Objectives

This study aimed to (1) compare the effectiveness of a Nordic hamstring exercise (NHE) versus single-leg Romanian deadlift (SLRDL) exercise programme on a hamstring injury risk surrogate; (2) compare the muscle soreness experienced by both exercise programmes; and (3) assess compliance to remote injury prevention exercise protocols through video software.

Methods

Twenty participants (10 women and 10 men: 21.45±1.6 years; 176±23 cm; 70±10 kg) were randomised into an NHE or SLRDL programme for 6 weeks. Single-leg hamstring bridge (SLHB), a hamstring injury surrogate, was the primary outcome for exercise efficacy. Muscle soreness and exercise adherence were also assessed. Significance was set at p<0.05.

Results

Both exercises increased SLHB performance resulting in an overall effect (p=0.013) with no effect for group (p=0.470) and no interaction effect (p=0.709), indicating both groups improved but there was no difference in improvement between interventions. There was no difference in muscle soreness between groups (p=0.087). Finally, both groups had 100% adherence to the programme.

Conclusions

Both the NHE and SLRDL are equally effective in increasing SLHB performance and demonstrate a similar level of muscle soreness. This suggests that SLRDL may be a viable option as a preventative exercise to mitigate the risk of hamstring injury. Finally, implementing injury prevention programmes remotely has the potential to enhance adherence.

Acute enhancement of Romanian deadlift performance after consumption of caffeinated chewing gum

This study investigates the effect of the consumption of caffeinated chewing gum on the performance of Romanian deadlift on the flywheel training device. A total of 19 participants completed a randomized, cross-over, single-blind experiment with food-grade caffeinated chewing gum trial (CAF) or placebo trail (PL). Gum were chewed for 10 min and rest for 15 min prior to the Romanian deadlift test using the inertial resistance training machine. 5 sets of 6 Romanian deadlifts were performed, with a 3-min rest between sets, followed by a 7-day washout period before the next set of trials. The average power, average force, total peak power, peak concentric power, peak eccentric power, heart rate, and rating of perceived exertion (RPE) for each trials were analyzed using paired-T test. Compared to placebo, caffeinated chewing gum trial enhanced peak concentric power (P = 0.016, Cohen's d = 0.44), peak eccentric power (P = 0.005, Cohen's d = 0.55), average power (P = 0.013, Cohen's d = 0.43), and total work (P = 0.026, Cohen's d = 0.28). However, in average force (P = 0.063, Cohen's d = 0.50), RPE (P = 0.266), and heart rate (P = 0.143), were no significant differences between trials. Caffeinated chewing gum with a dose of caffeine of 200 mg for 10 min may acutely enhance Romanian deadlift performance on the flywheel machine.

Muscle forces and fascicle behavior during three hamstring exercises

Knowledge about muscular forces and fascicle behavior during hamstring exercises can optimize exercise prescription, but information on these outcomes across different exercises is lacking. We aimed to characterize and compare lower‐limb muscle forces and biceps femoris long head muscle fascicle behavior between three hamstring exercises: the Nordic hamstring curl (NHC), single‐leg Roman chair (RCH), and single‐leg deadlift (DL). Ten male participants performed the exercises while full‐body kinematics, ground reaction forces, surface muscle activation, and biceps femoris long head fascicle behavior were measured. Mean fascicle length was highest in the DL, followed by the RCH and NHC. Fascicle lengthening was higher in the NHC compared with the RCH and DL, with no difference between the RCH and DL. Biceps femoris short and long head, semitendinosus, and semimembranosus peak forces were generally higher in the NHC compared with the RCH and DL, while mean forces during the eccentric phase were generally not different between the NHC and RCH. Peak forces in the NHC coincided with low biceps femoris long head and semimembranosus muscle activation. The NHC generally has the highest peak hamstring muscle forces and results in more fascicle lengthening when compared to the DL and RCH. The NHC may therefore be most effective to promote increases in fascicle length. While the NHC may be effective to promote biceps femoris short head and semitendinosus strength adaptations, the RCH and DL may be more effective to promote strength increases in the biceps femoris long head and semimembranosus.