Isokinetic Muscular Strength and Aerobic Physical Fitness in Recreational Long-Distance Runners: A Cross-Sectional Study

Abstract

Isokinetic muscular strength and aerobic physical fitness in recreational long-distance runners: A cross-sectional study. J Strength Cond Res 36(3): e73-e80, 2022-Muscular strength, bilateral asymmetry, and imbalance between antagonist muscles have been considered as risk factors for knee injuries. Moreover, muscular strength has also been associated with aerobic performance. The aim of the study was to investigate bilateral muscular symmetry and muscular strength balance assessed by isokinetic dynamometry in recreational longdistance runners and to verify whether knee muscular strength would be associated with maximal oxygen uptake (V Ȯ2 max), anaerobic threshold (AT), and running economy (RE). Thirty-nine runners (male [n 5 24]: age, 30 6 8 years; height, 176.0 6 7.3 cm; body mass, 70.3 6 8.0 kg; race pace below 4:30 min•km 21 and female [n 5 15]: age, 31 6 7 years; height, 163.0 6 3.8 cm; body mass, 55.9 6 4.7 kg; race pace below 5:00 min•km 21 ) participated in this study. Comparing the conventional knee balance ratio with the literature recommendation (60%), male runners presented significantly lower values for the nondominant side (55.5 6 7.3%; p 5 0.001; d 5 0.85; confidence interval [CI] 5 0.47 to 1.20) but not for the dominant side (58.1 6 6.8%; p 5 0.208; d 5 0.37; CI 5 20.12 to 0.86). Female runners presented lower values for both sides (52.1 6 7.1%; p 5 0.001; d 5 1.55; CI 5 0.86 to 2.20 and 50.7 6 8.0%; p 5 0.001; d 5 1.62; CI 5 0.90 to 2.30 for dominant and nondominant sides, respectively). Female and male runners presented nonfunctional ratio imbalance and asymmetry of bilateral strength. Strength outcomes were not associated with V Ȯ2 max, AT, or RE. In conclusion, recreational runners were characterized by an imbalance in muscular strength between knee flexor and extensor muscles, which was more obvious in female runners, and by symmetrical thigh muscle strength values. Moreover, muscular isokinetic knee flexor and extensor muscle strength was not associated with aerobic fitness parameters.

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

“…Knee joint flexor/extensor muscles and ankle joint plantar flexor/dorsiflexor muscles PT were measured using a motor-driven dynamometer (D&R Ferstl GmbH, Hemau, Germany) ( Figure 3A ) as this test showed high ICC (knee: 0.90 to 0.96; ankle: 0.77–0.98) in previous study ( Gonosova et al, 2018 ; Andrade et al, 2021 ). The subjects performed two trials to access the right lower-limb knee joint flexion/extension and ankle joint plantarflexion/dorsiflexion PT.…”

“…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.…”

The Effect of Muscle Strength on Marathon Race-Induced Muscle Soreness

“…The dominant lower limb was determined by asking the participant which limb they prefer to use to kick a ball. This procedure was used in previous studies [ 28 , 29 ].…”

Relationship Between Isokinetic Lower-Limb Joint Strength, Isometric Time Force Characteristics, and Leg-Spring Stiffness in Recreational Runners

“…The muscles around the knee and ankle joints may play an important role in regulating leg-spring stiffness (Novacheck, 1998;Bohm et al, 2019). PT of the right knee joint flexor/extensor muscles and ankle joint plantar flexor/dorsiflexor muscles was measured using a motor-driven dynamometer (D&R Ferstl GmbH, Hemau, Germany), which showed high ICC (knee: 0.90-0.96; ankle: 0.77-0.98) in previous studies (Gonosova et al, 2018;Andrade et al, 2021). Before each test, the equipment was calibrated according to the instructions of the manufacturer.…”

“…All participants performed three warm-up trials using sub-maximum effort to familiarize themselves with the test movements. The subjects then performed five concentric and eccentric isokinetic contractions at angular velocities of 60 •s −1 for each knee and ankle joint, which could reliably and accurately evaluate PT (Larsson et al, 2006;Silva et al, 2018;Andrade et al, 2021). The PT was calculated as the greatest torque value during isokinetic concentric and eccentric phases and was collected for further analysis (Figure 2).…”