Differences in Muscle Mechanical Properties Between Elite Power and Endurance Athletes

Abstract

The aim of this study was to compare muscle mechanical properties (using tensiomyography-TMG) and jumping performance of endurance and power athletes and to quantify the associations between TMG parameters and jumping performance indices. Forty-one high-level track and field athletes from power (n = 22; mean ± SD age, height, and weight were 27.2 ± 3.6 years; 180.2 ± 5.4 cm; and 79.4 ± 8.6 kg, respectively) and endurance (endurance runners and triathletes; n = 19; mean ± SD age, height, and weight were 27.1 ± 6.9 years; 169.6 ± 9.8 cm; 62.2 ± 13.1 kg, respectively) specialties had the mechanical properties of their rectus femoris (RF) and biceps femoris (BF) assessed by TMG. Muscle displacement (Dm), contraction time (Tc), and delay time (Td) were retained for analyses. Furthermore, they performed squat jumps (SJs), countermovement jumps (CMJs), and drop jumps to assess reactive strength index (RSI), using a contact platform. Comparisons between groups were performed using differences based on magnitudes, and associations were quantified by the Spearman's ρ correlation. Power athletes showed almost certain higher performance in all jumping performance indices when compared with endurance athletes (SJ = 44.9 ± 4.1 vs. 30.7 ± 6.8 cm; CMJ = 48.9 ± 4.5 vs. 33.6 ± 7.2 cm; RSI = 2.19 ± 0.58 vs. 0.84 ± 0.39, for power and endurance athletes, mean ± SD, respectively; 00/00/100, almost certain, p ≤ 0.05), along with better contractile indices reflected by lower Dm, Tc, and Td (Tc BF = 14.3 ± 2.3 vs. 19.4 ± 3.3 milliseconds; Dm BF = 1.67 ± 1.05 vs. 4.23 ± 1.75 mm; Td BF = 16.8 ± 1.6 vs. 19.6 ± 1.3 milliseconds; Tc RF = 18.3 ± 2.8 vs. 22.9 ± 4.0 milliseconds; Dm RF = 4.98 ± 3.71 vs. 8.88 ± 3.45 mm; Td RF = 17.5 ± 1.0 vs. 20.9 ± 1.6 milliseconds, for power and endurance athletes, mean ± SD, respectively; 00/00/100, almost certain, p ≤ 0.05). Moderate correlations (Spearman's ρ between -0.61 and -0.72) were found between TMG and jumping performance. The power group presented better performance in vertical jumps, supporting the validity of these tests to distinguish between endurance and power athletes. Furthermore, TMG can discriminate the "athlete-type" using noninvasive indices moderately correlated with explosive lower-body performance. In summary, both vertical jump and TMG assessments could be useful in identifying and selecting young athletes.

Muscle mechanical properties of strength and endurance athletes and changes after one week of intensive training

“…The differences between groups at the baseline measurement (Table 1 and Figure 5) are consistent with Loturco et al (2015), who also observed differences in TMG mechanical properties and CMJ performance between elite endurance, and power track and field athletes. These results show that experienced strength/power athletes have an advanced contractile capacity (e.g., time necessary for the muscle fiber contraction) in comparison with endurance athletes.…”

“…Albeit neural aspects (e.g., number and type of motor units recruited) play a significant role during the execution of different types of physical activity (Sale, 1987), muscle contractile properties (e.g., intrinsic muscular qualities) are key determinants of performance in both strength and endurance athletes (Costill et al, 1976;García-García et al, 2015;Lattier et al, 2003;Loturco et al, 2015). Accordingly, sprinters have a faster fiber type dominance, which favours a powerful muscle contraction in comparison with endurance runners, which in the other hand show higher proportion of slow fiber type (Costill et al, 1976).…”

“…In the applied field, there is an intense demand for sensitive and practical tools that would help to predict athletic performance in different types of sport (García-García et al, 2015;Loturco et al, 2015) and to understand the effects of intensive training periods (Kellmann and , 2000). A large amount of the procedures commonly available are either invasive or motivation dependent, and might induce fatigue (Bosco et al, 1983;Breil et al, 2010;Fry et al, 1994).…”

“…It may provide an additional advantage in the applied field to detect between-group differences in cross-sectional comparisons (e.g., talent detection) and within-group changes in longitudinal assessments (e.g., after training and rest periods), as it allows a non-invasive evaluation of the contractile properties (Carrasco et al, 2011;de Paula Simola et al, 2015;Hunter et al, 2012) without producing additional fatigue, and examines muscle in isolation (García-García et al, 2015;Loturco et al, 2015). The TMG mechanical properties have been used to investigate the effects of different types of physical exercise, such as strength (de Paula Simola et al, 2015;García-Manso et al, 2012;Hunter et al, 2012) and endurance (García-Manso et al, 2011), besides estimating the fiber typer composition in skeletal muscle (Simunic et al, 2011).…”

“…The TMG mechanical properties have been used to investigate the effects of different types of physical exercise, such as strength (de Paula Simola et al, 2015;García-Manso et al, 2012;Hunter et al, 2012) and endurance (García-Manso et al, 2011), besides estimating the fiber typer composition in skeletal muscle (Simunic et al, 2011). Nonetheless, information concerning differences in TMG mechanical properties of typical endurance and strength/power athletes is spare (Loturco et al, 2015). Furthermore, as far as we know, no study has examined the specific TMG response characteristics after intensive training periods.…”