WETENSCHAPPELIJKE ONDERBOUWING

PETRÉ ET AL. 2018

Meta analysis made at University of Sport and Health Science in Stockholm (GIH) by Henrik Petré, MSc with supervisor Mikael Mattson, PhD. In the Meta-analysis they looked at outcomes important or defining for performance and eventually 15 studies met the inclusion criteria. The study shows that when it comes to flywheel training and hypertrophy you see significant increases in muscle mass in a shorter time frame compared to traditional weight training. The largest gains and effect sizes associated with flywheel training are seen for maximal strength and power. Vertical movement is showing moderate effect size and horizontal movement small effect size. Data suggests flywheel training is more effective for younger and better-trained subjects.

WEAKLEY ET AL. 2019

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. Very large to nearly perfect relationships were observed between the two measures, with trivial to moderate bias reported. The researchers concluded that the kMeter app demonstrates acceptable levels of validity.

ILLERA-DOMÍNGUEZ ET AL. 2018

This study showed a paradigm-shifting increase of 5.5% muscle mass in the thighs in only two weeks of flywheel squatting. Historically gains in muscle mass has been thought to be a delayed response to chronic training. However, already in 2008 Norrbrand et al* showed robust and early gains in muscle mass with flywheel but this is now repeated and shown in the normal vertical squat. On top of that, the gains in muscle mass were accompanied with a 30% increase in force and a 50% increase in concentric and eccentric power over four weeks.

MAROTO IZQUIERDO ET AL. 2017

Meta-analysis from 2017 including 276 subjects from 9 studies comparing outcomes between flywheel eccentric overload training (FWEOT) vs traditional weight training. The meta-analysis showed significant differences between FWEOT vs. conventional resistance training in concentric and eccentric strength, power, hypertrophy, vertical jump height and running speed, favouring FW-EOT. No surprise for you read up on the subject since actually all studies comparing flywheel devices (with the same design as the kBox) vs weights shows flywheel to be superior. The only studies with a similar or lesser effect are a few using a conic flywheel and sometimes comparing different exercises so not all are actually FW vs weights studies either. This is shown pretty clear on the far right in this graph where all studies favour flywheel training.

GUAL ET AL. 2015

A Spanish research group (Gual, G., Fort-Vanmeerhaeghe, A. & Romero-Rodríguez, D. 2015) examined flywheel training with eccentric overload during season for a population at risk for patellar tendinopathy. 81 (38 women and 43 men) basketball and volleyball players conducted a 24-week long intervention period. 37 of the subjects performed one training session a week with flywheel training (squat; 4 sets x 8 reps). 44 of the subjects maintained in their regular scheduled in-season training routines. Results: Both CMJ and Power were significantly (p<0.05) different between groups in favour of the flywheel group. No player in the flywheel group suffered from patellar tendinopathy during the intervention period. Conclusion: Adding a weekly eccentric overload squat training bout to a regular basketball and volleyball exercise routine, enhances lower limb muscle power in flywheel device and vertical jump performance without triggering the patellar tendon complaints. “Effects of in-season inertial resistance training with eccentric overload in a sports population at risk for patellar tendinopathy”