Flywheel Training Research Articles

Post-activation performance enhancement (PAPE) after a single bout of high-intensity flywheel resistance training.

This study investigated the post-activation performance enhancements (PAPE) induced by a high-intensity single set of accentuated eccentric isoinertial resistance exercise on vertical jump performance. Twenty physically active male university students performed, in randomized counterbalanced order, two different conditioning activities (CA) after a general preestablished warm-up: a conditioning set of 6 maximum repetitions at high intensity (i.e., individualized optimal moment of inertia [0.083 ± 0.03 kg·m-2]) of the flywheel half-squat exercise in the experimental condition, or a set of 6 maximal countermovement jumps (CMJ) instead of the flywheel exercise in the control condition. CMJ height, CMJ concentric peak power and CMJ concentric peak velocity were assessed at baseline (i.e., 3 minutes after the warm-up) and 4, 8, 12, 16 and 20 minutes after the CA in both experimental and control protocols. Only after the experimental protocol were significant gains in vertical jump performance (p < 0.05, ES range 0.10–1.34) at 4, 8, 12, 16 and 20 minutes after the CA observed. In fact, the experimental protocol showed greater (p < 0.05) CMJ height, concentric peak power and concentric peak velocity enhancements compared to the control condition. In conclusion, a single set of high-intensity flywheel training led to PAPE in CMJ performance after 4, 8, 12, 16 and 20 minutes in physically active young men.

FLYWHEEL TRAINING IN MUSCULOSKELETAL REHABILITATION: A CLINICAL COMMENTARY

5.

Eccentric Overload Flywheel Training in Older Adults.

Age-related reductions in muscle strength and muscle power can have significant adverse effects on functional performance in older adults. Exercise training has been shown to be a potent stimulus for improvements in strength and power. However, investigation into how to best optimize training-related adaptations, as well as the accessibility of training methods, is needed. Traditional (TR) methods using gravity-dependent free-weights or weight machines can improve and maintain strength and power but are limited in their ability to provide constant muscle tension and high levels of muscle activation throughout the lowering (eccentric) phase of lifting. Eccentric overload (EO) training may overcome these limitations and has been shown to result in potent adaptations in both young and older adults. Methods of producing EO are significantly limited from a practical perspective. The addition of whole-body flywheel training equipment provides a practical method of producing EO and may be appropriate for older adults wanting to optimize training outcomes. Our review provides limited evidence of the use of eccentric overload flywheel training as a novel training method in seniors. Through the review of literature, EO training overcame some of the limitations set forth by traditional resistance training and demonstrated to have key benefits when combating age-related changes affecting muscle strength and muscle power. It can be concluded that EO training is an important addition to the training arsenal for older adults. Flywheel training provides a practical method of achieving EO, increasing strength and power, combating age-related adaptations, and overall improving quality of life in older adults.

Criterion Validity of Force and Power Outputs for a Commonly Used Flywheel Resistance Training Device and Bluetooth App.

Weakley, J, Fernández-Valdés, B, Thomas, L, Ramirez-Lopez, C, and Jones, B. Criterion validity of force and power outputs for a commonly used flywheel resistance training device and bluetooth app. J Strength Cond Res 33(5): 1180-1184, 2019-Flywheels are a resistance training device that can increase lean body mass, strength, and power. However, because of their unique design and the inertia from the concentric portion directly relating to the force that is applied during the eccentric portion, monitoring the training stimulus can be difficult. Consequently, the aim of this study was to assess the validity of the kMeter app for quantifying force and power at a range of different isoinertial loads from a flywheel training device when compared against a criterion measure. Eleven subjects volunteered to take part in this study, with subjects completing between 5 and 35 repetitions of the harness squat with 0.05, 0.10, 0.15 kg·m isoinertial load. A synchronized dual force plate and tricamera optoelectronic setup was used as the criterion measure to calculate force and power output, while the kMeter app was used as the practical measure. Very large to nearly perfect relationships were observed between the 2 measures, with trivial to moderate bias reported. In addition, typical error of the estimate (TEE) was found to be <10% at all isoinertial loads. These findings suggest that the kMeter app, when used in conjunction with the kBox flywheel device, demonstrates acceptable levels of validity. However, because of the TEE, the kMeter app may not be able to accurately detect small differences and therefore be suitable for research purposes. These findings suggest that the kMeter app is an acceptable method of monitoring flywheel resistance training. Furthermore, it is advised that practitioners use mean power rather than mean force.

Eccentric hamstring training in elite AFL athletes promotes improvements in lower limb strength

Introduction: In elite Australian Rules Football (AFL), hamstring strain injuries (HSI) are the most common cause of time lost from training and matches. Additionally, athletes with low levels of eccentric strength have been shown to be at a greater risk of HSI than stronger individuals. Recent research using various interventions to improve eccentric strength are limited in their application to the elite level due to their recreational cohorts. Therefore, the aim of this study was to determine the impact of Nordic hamstring exercise (NHE) and hip-based flywheel training on lower limb and eccentric knee flexor strength in elite Australian Footballers.

Myocellular Responses to Concurrent Flywheel Training during 70 Days of Bed Rest.

This investigation evaluated myocellular responses to an integrated resistance and aerobic training program during 70 d of bed rest. Training was 6 d·wk on a small-footprint gravity-independent flywheel resistance and aerobic device; 3 d of maximal flywheel supine quadriceps and calf exercises with continuous rowing separated by 4 to 6 h, and 3 d of interval rowing. Vastus lateralis (VL) and soleus (SOL) muscle biopsies were obtained from eight healthy males (age, 28 ± 4 yr; BMI, 25 ± 3 kg·m; V˙O2max, 42 ± 6 mL·kg·min) before and after 6° head-down tilt bed rest. Vastus lateralis and SOL myosin heavy chain (MHC) I and IIa single muscle fiber size and functional characteristics, as well as overall fiber type distribution, capillarization, and metabolic enzyme activities were evaluated. In the VL, MHC I size and power (absolute and normalized) were preserved. The MHC IIa fibers hypertrophied (+6%, P < 0.05) without a change in absolute power, so normalized power declined (-7%, P < 0.05). In the SOL, MHC I fibers atrophied (-9%) and absolute power declined (-17%) (P < 0.05), whereas normalized power was maintained. Size, absolute power, and normalized power were protected in the less-abundant MHC IIa fibers. Reduced MHC coexpressing hybrid fibers, generally indicative of an exercise training effect, was apparent in the VL, whereas fiber type was maintained in the SOL. Capillarization and metabolic enzymes were generally preserved or increased in VL and SOL. The integrated resistance and aerobic training protocol on a device maintains several key myocellular characteristics during prolonged unloading, but further refinement of the exercise approach to fully protect the SOL is warranted.

Eccentrically overloaded flywheel training increases biceps femoris long head fascicle length

Background: Recent evidence has shown that professional soccer players with short biceps femoris long head (BFlh) fascicles are 4 times more likely to suffer a hamstring strain injury (HSI) than those who have longer fascicles. Therefore, the aim of this study was to determine (i) the time course of fascicle length adaptations of the BFlh following two methods of flywheel leg curl training; (ii) if measurements of knee flexor isometric strength and rate of force development (RFD) as well as eccentric strength are altered following flywheel leg curl training.

Inertial flywheel resistance training and muscle oxygen saturation.

The inertial flywheel device causes an increase in eccentric overload during training. The aim was to study muscle oxygen saturation produced during an inertial flywheel squat training, comparing it with a barbell squat training. Twelve male adults performed a barbell squat training (3×8 reps, 75-80% 1RM) and a flywheel squat training (3×8 reps, all-out). Muscle oxygen saturation (%SmO2), total hemoglobin (tHb), reoxygenation, heart rate (HR), lactate, vertical jumps, maximal voluntary isometric contraction and rated perceived exertion (RPE) were studied. Both protocols produced a significant decrease in %SmO2 and tHB during the sets of squats, and a significant increase in HR, lactates dand RPE after training. The flywheel squat protocol caused a greater decrease in %SmO2 than the barbell squat protocol in each of the sets of exercises (1st set: -67.5±7.2% vs. -53.7±16.2%; 2nd set: -67.2±13.5% vs. -53.6±15.4%; 3rd set: -68.1±13.0% vs. -55.0±17.0%), as well as a longer reoxygenation after finishing the training (61.7±12.6 vs. 55.7±13.7 s). Although no differences were found on a muscle fatigue level, the flywheel training brought on greater physiological stress than the barbell squat training, observing a greater decrease in muscle oxygen saturation and a longer reoxygenation.

Effects of Traditional Versus Horizontal Inertial Flywheel Power Training on Common Sport-Related Tasks.

This study aimed to analyze the effects of power training using traditional vertical resistance exercises versus direction specific horizontal inertial flywheel training on performance in common sport-related tasks. Twenty-three healthy and physically active males (age: 22.29 ± 2.45 years) volunteered to participate in this study. Participants were allocated into either the traditional training (TT) group where the half squat exercise on a smith machine was applied or the horizontal flywheel training (HFT) group performing the front step exercise with an inertial flywheel. Training volume and intensity were matched between groups by repetitions (5–8 sets with 8 repetitions) and relative intensity (the load that maximized power (Pmax)) over the period of six weeks. Speed (10 m and 20 m), countermovement jump height (CMJH), 20 m change of direction ability (COD) and strength during a maximal voluntary isometric contraction (MVIC) were assessed before and after the training program. The differences between groups and by time were assessed using a two-way analysis of variance with repeated measures, followed by paired t-tests. A significant group by time interaction (p=0.004) was found in the TT group demonstrating a significantly higher CMJH. Within-group analysis revealed statistically significant improvements in a 10 m sprint (TT: −0.17 0.27 s vs. HFT: −0.11 0.10 s), CMJH (TT: 4.92 2.58 cm vs. HFT: 1.55 2.44 cm) and MVIC (TT: 62.87 79.71 N vs. HFT: 106.56 121.63 N) in both groups (p < 0.05). However, significant differences only occurred in the 20 m sprint time in the TT group (−0.04 0.12 s; p = 0.04). In conclusion, the results suggest that TT at the maximal peak power load is more effective than HFT for counter movement jump height while both TT and HFT elicited significant improvements in 10 m sprint performance while only TT significantly improved 20 m sprint performance.

Skating Crossovers on a Motorized Flywheel

Ice hockey requires frequent skater crossovers to execute turns. Our investigation aimed to determine the effectiveness of training crossovers on a motorized, polyethylene high-resistance flywheel. We hypothesized that high school hockey players training on the flywheel would perform as well as their peers training on ice. Participants were 23 male high-school hockey players (age 15-19 years). The study used an experimental prospective design to compare players who trained for 9 sessions on the 22-foot flywheel with players who trained for 9 sessions on a similarly sized on-ice circle. Both groups were compared with control subjects who were randomly selected from the same participant pool as those training on ice. All players were tested before and after their 3-week training regimens, and control subjects were asked to not practice crossovers between testing. Group 1 trained in a hockey training facility housing the flywheel, and group 2 trained in the ice hockey arena where testing occurred. Primary outcome measures tested in both directions were: (a) speed (time in seconds) required to skate crossovers for 3 laps of a marked face-off circle, (b) cadence of skating crossovers on the similarly sized circles, and (c) a repeat interval speed test, which measures anaerobic power. No significant changes were found between groups in on-ice testing before and after training. Among the group 1 players, 7 of 8 believed they benefited from flywheel training. Group 2 players, who trained on ice, did not improve performance significantly over group 1 players. Despite the fact that no significant on-ice changes in performance were observed in objective measures, players who trained on the flywheel subjectively reported that the flywheel is an effective cost-effective alternative to training on ice. This is a relevant finding when placed in context with limited availability of on-ice training.

Neuromuscular and balance responses to flywheel inertial versus weight training in older persons

Aim Loss of muscle strength and balance are main characteristics of physical frailty in old age. Postural sway is associated with muscle contractile capacity and to the ability of rapidly correcting ankle joint changes. Thus, resistance training would be expected to improve not only strength but also postural balance. Methods In this study, age-matched older individuals (69.9±1.3 years) were randomly assigned to flywheel ( n=12), or weight-lifting ( n=12) groups, training the knee extensors thrice weekly for 12 weeks. The hypotheses were that owing to a larger eccentric loading of the knee extensors, flywheel training would result in (a) greater gains in quadriceps strength; (b) greater improvements in balance performance compared with weight-lifting training. Isokinetic dynamometry, B-mode ultrasonography, electromyography, percutaneous muscle stimulation and magnetic resonance imaging were employed to acquire the parameters of interest. Results Following training, knee extensors peak isokinetic power increased by 28% ( P<0.01) in the flywheel group with no change in the weight-lifting group. Adaptations of the gastrocnemius muscle also occurred in both groups. The gastrocnemius characteristic with the highest response to training was tendon stiffness, with increases of 54% and 136% in the weight-lifting and flywheel groups, respectively ( P<0.01). The larger increase in tendon stiffness in the flywheel group was associated with an improvement in postural balance ( P<0.01). Conclusion Quadriceps flywheel loading not only produces a greater increase in power than weight training but its physiological benefits also transfer/overspill to the plantarflexor muscle–tendon unit resulting in a significantly improved balance. These findings support our initial hypotheses.

Vertical jump performance after 90 days bed rest with and without flywheel resistive exercise, including a 180 days follow-up

Muscle atrophy and neuromuscular de-conditioning occur in response to space flight and bed-rest. In this study, we investigated the efficacy of flywheel training to conserve jumping power and height during 90 days bed rest. Twenty-four young healthy men underwent strict bed-rest (-6 degrees head down tilt) for 90 days. Eight participants were assigned to a flywheel group (FW) and 16 to a control group (Ctrl). The ground reaction force was measured during vertical jump tests twice during baseline data collection, and on day 4, 7, 14, 90 and 180 of recovery. In half of the participants, jump tests were also performed within minutes after re-ambulation and on four more occasions during the first 2 days of recovery. Jump height was reduced from 40.6 cm (SD 6.1 cm) during the first baseline measurement to 27.6 cm (SD 5.6 cm) on day 4 of recovery in Ctrl, but only from 38.6 cm (SD 3.9 cm) to 34.4 cm (SD 6.5 cm) in FW (P < 0.001). At the same time, peak power was reduced from 47.4 W/kg (SD 8.0 W/kg) to 34.5 W/kg in Ctrl, but only from 46.2 W/kg (6.0 W/kg) to 42.2 W/kg SD 4.6 W/kg) in FW (P < 0.001). Jump height and peak power were completely recovered after 163 and 140 days in Ctrl, respectively, and after 72 and 18 days in FW (regression analysis). In conclusion, flywheel exercise could effectively offset neuromuscular de-conditioning during bed-rest, and led to full recovery at an earlier stage. These findings nourish the hope that adequate training paradigms can fully sustain neuromuscular function under microgravity conditions.

Early skeletal muscle hypertrophy and architectural changes in response to high-intensity resistance training

The onset of whole muscle hypertrophy in response to overloading is poorly documented. The purpose of this study was to assess the early changes in muscle size and architecture during a 35-day high-intensity resistance training (RT) program. Seven young healthy volunteers performed bilateral leg extension three times per week on a gravity-independent flywheel ergometer. Cross-sectional area (CSA) in the central (C) and distal (D) regions of the quadriceps femoris (QF), muscle architecture, maximal voluntary contraction (MVC), and electromyographic (EMG) activity were measured before and after 10, 20, and 35 days of RT. By the end of the training period, MVC and EMG activity increased by 38.9 +/- 5.7 and 34.8% +/- 4.7%, respectively. Significant increase in QF CSA (3.5 and 5.2% in the C and D regions, respectively) was observed after 20 days of training, along with a 2.4 +/- 0.7% increase in fascicle length from the 10th day of training. By the end of the 35-day training period, the total increase in QF CSA for regions C and D was 6.5 +/- 1.1 and 7.4 +/- 0.8%, respectively, and fascicle length and pennation angle increased by 9.9 +/- 1.2 and 7.7 +/- 1.3%, respectively. The results show for the first time that changes in muscle size are detectable after only 3 wk of RT and that remodeling of muscle architecture precedes gains in muscle CSA. Muscle hypertrophy seems to contribute to strength gains earlier than previously reported; flywheel training seems particularly effective for inducing these early structural adaptations.