Hip muscular strength balance is associated with running economy in recreationally-trained endurance runners

Abstract

BackgroundThe percentage of sustained maximal oxygen uptake and the running economy are important factors that determine the running success of endurance athletes. Running economy is defined as the oxygen uptake required to run at a given speed and depends on metabolic, cardiorespiratory, biomechanical, neuromuscular, and anthropometric factors. With regard to anthropometric characteristics, total body mass seems to be a crucial factor for the running economy. Moreover, neuromuscular components, especially knee muscular strength and the strength balance ratio, also seem to be critical for the running economy. In addition to knee muscle strength, hip muscle strength is also an important contributor to running performance on level or hilly ground. However, the relationship between running economy and the hip muscles is unknown. Thus the aim of the present study was to verify whether hip flexor and extensor isokinetic peak torque, the isokinetic strength balance ratio, total body mass and fat free mass were associated with running economy in both sexes and to compare sex differences in physical fitness and isokinetic strength characteristics.MethodsA total of 24 male (31.0 ± 7.7 years, 176.2 ± 7.3 cm, and 70.4 ± 8.4 kg) and 15 female (31.3 ± 6.7 years, 162.9 ± 3.9 cm, and 56.0 ± 5.3 kg) recreationally-trained endurance runners were recruited. Maximal oxygen uptake, running economy, conventional (concentric flexors-to-concentric extensors) and functional (concentric flexors-to-eccentric extensors) hip isokinetic strength balance ratios, peak torque of the hip flexor and extensor muscles, total body mass, and fat-free mass were measured. Running economy was assessed on two separate days by means of the energy running cost (Ec) using a motorized treadmill at 10.0 and 12.0 km h−1 (3% gradient) and 11.0 and 14.0 km h−1 (1% gradient).ResultsThe functional balance ratio was significantly and negatively associated with Ec at 11.0 (r = − 0.43, P = 0.04) and 12.0 km h−1 (r = − 0.65, P = 0.04) when using a 3% gradient in male runners. Considering muscular strength, male runners only showed a significant relationship between Ec (assessed at 12 km h−1 and a 3% gradient) and peak torque for extensor muscle eccentric action (r = 0.72, P = 0.04). For female runners, only peak torque relative to total body mass for extensor muscles (180° s−1) was positively associated with Ec when assessed at 10 km h−1 using a 3% gradient (r = 0.59, P = 0.03). No significant relationships were found between Ec and total body mass or fat-free mass.DiscussionGiven that the functional balance ratio was associated with a better Ec, coaches and athletes should consider implementing a specific strengthening program for hip flexor muscles to increase the functional ratio.

Not Lower-Limb Joint Strength and Stiffness but Vertical Stiffness and Isometric Force-Time Characteristics Correlate With Running Economy in Recreational Male Runners

“…All participants performed three sub-maximal trials to familiarise themselves with the test. As the most commonly used angular speed during isokinetic testing procedures is 60°s −1 , which has been suggested to reliably and accurately evaluate maximal capacities of the muscles to produce force ( Zapparoli and Riberto., 2017 ; Silva et al, 2018 ), five repetitions of concentric and eccentric isokinetic PT were evaluated on the knee and ankle joints at 60° s −1 in the present study ( Luna et al, 2012 ; Andrade et al, 2021 ). There was a rest period of 1 min between contraction type and a 10-min break between trials.…”

“…To summary, regarding recreational runners, the benefits of neuromuscular factors on the RE have not been sufficiently studied ( Sundby and Gorelick, 2014 ; Silva et al, 2018 ; Lum et al, 2020 ). As the increasing number of recreational runners worldwide, identifying these key neuromuscular profiles may benefit runners as this knowledge could be applied to improve RE and running performance through a more optimal strength training program design.…”

Factors Influencing Running Performance During a Marathon: Breaking the 2-h Barrier

“…These data were confirmed in two meta-analyzes: even in highly trained runners, strength training in addition to improving maximum power and strength, reduces the energy cost of running ( 14 , 15 ). Moreover, a greater hip flexor muscle strength relative to extensor muscle seems to be associated with a better RE, especially in male runners ( 16 ).…”

The investigation of isokinetic knee strength and muscle balance of taekwondo and wrestling athletes

“…Tatlici et al (2021) reported that 8-week wrestling training reduced the H/Q muscle ratio, strengthened the extensor quadriceps muscle, but did not cause a significant change in the strength of the flexor hamstring muscle, and recommended that specific hamstring exercises should be added to the training programs to prevent injuries. Studies have shown that the muscular balance in the lower extremities is related to the general body balance and oxygen utilization capacity, and that a developed muscular balance positively affects these parameters (Heitkamp et al, 2001;Silva et al, 2018). These variables are of vital importance for wrestling and it is known that an athlete with advanced motor features is advantageous during the wrestling match (Kuzmina et al, 2017;Moran-Navarro et al, 2015;Murlasits, 2004).…”