Long Ground Contact Time Enhances Running Economy at High-Intensity Running

The Relationship Between Running Biomechanics and Running Economy: A Systematic Review and Meta-Analysis of Observational Studies

“…; no subtraction reported Separate; pressure insoles and force platform; treadmill; not reported; not reported Average vertical peak eccentric and concentric force; average horizontal peak eccentric and concentric force; average peak force total; contact time; step frequency; step length; time to peak force Tam et al [ 101 ]; correlational 14/0; 24.2 ± 4.2; 170.5 ± 6.3; 54.8 ± 6.3; Kenyan Elite runners; 10-km race time 28.7 min ± 0.4 min, half-marathon time 62.2 ± 1.0 min; 128.9 ± 18.8 km∙week −1 ; running experience not reported; (in mLO 2 ∙kg −1 ∙min −1 ) 71.9 ± 5.1; RE (in kcal∙kg −1 ∙km −1 ) 0.94 ± 0.18 over a 12-km run and 0.93 ± 0.08 over a 20-km run Stationary gas analyzer (Quark, Cosmed, Rome, Italy); 3.33 m∙s −1 and 5.56 m∙s −1 ; 6 min; last 0.5 min used for data analysis; speeds were slower than lactate threshold of each athlete, and RER < 1.0 kcal∙kg −1 ∙km −1 ; Lusk equation; no subtraction performed Separate; 3D motion capture at 250 Hz and force platform at 2000 Hz; 60-m indoor synthetic track, RE determined on treadmill with 1% incline; not reported; right side Rectus femoris–biceps femoris co-activation; rectus femoris–gluteus medius co-activation Tam et al [ 102 ]; correlational 30/0; 25.8 ± 5; 175.2 ± 7.5; 66 ± 13.3; not reported Trained runners; PB 10 km 36.03 ± 7.46; weekly training distance, running experience and not reported; RE (in mLO 2 ∙kg −1 ∙km −1 ) 206.03 ± 19.02 Stationary gas analyzer (Quark, Cosmed Rome, Italy); 3.3 m∙s −1 ; 6 min; last 0.5 min used for data analysis; speeds were slower than lactate threshold of each athlete, RER < 1.0 mLO 2 ∙kg −1 ∙km −1 ; n.a. ; no subtraction reported Separate; 3D motion capture at 250 Hz and force platform at 2000 Hz; treadmill at 1% incline; biomechanical data on a 60-m indoor synthetic running track; no standardized shoes; EMG was only measured for the right limb, other data both limbs Ground contact time; stride frequency; stride duration; swing time; stride length; ankle stiffness; knee stiffness; lateral gastrocnemius and tibialis anterior co-activation; medial gastrocnemius; lateral gastrocnemius; tibialis anterior; peroneus longus; biceps femoris; rectus femoris; gluteus medius Tanji et al [ 108 ]; correlational 11/0; 22.4 ± 3.1; 182 ± 6; 68.5 ± 7.7; not reported Highly trai...…”

“…Several studies reported RE in multiple units, and thus the total is higher than 51. Forty studies described methods used to check for a steady state, which included verification of the respiratory exchange ratio below 1.0 (22 studies [ 24 , 39 , 40 , 80 , 81 , 86 , 88 – 90 , 93 – 104 ], measurement of blood lactate concentration (12 studies [ 23 , 24 , 40 – 43 , 82 , 92 , 105 – 108 ]), and visual inspection of a plateau in the oxygen consumption ( ) and/or carbon dioxide expired data (21 studies [ 34 , 35 , 39 , 80 , 82 , 84 – 86 , 88 – 90 , 94 – 96 , 98 , 99 , 106 , 109 – 112 ]). Most studies ( k = 18) employed multiple methods to check for steady state [ 32 , 83 , 87 , 113 – 120 ], while 11 studies did not report any steady-state verification.…”

“…In further support, one study included in this review found earlier onset of rectus femoris muscle activation was associated with a lower oxygen cost [ 114 ]. In contrast, measures of tendon stiffness were not associated with joint stiffness during hopping [ 149 ] or joint angles at initial contact during running [ 108 ]. Similarly, groups differing in Achilles tendon stiffness showed no significant differences in ankle joint kinematics during running [ 82 ].…”

“…Related to this, some studies did not report whether they verified a steady-state oxygen consumption to ensure a submaximal intensity. We excluded some studies (e.g., [ 100 ]) or specific speeds within other studies (e.g., 6 m∙s −1 in [ 108 ] or 5.83 m∙s −1 in [ 85 ]) as these were very likely not at a metabolic steady-state. While for some other included studies/speeds it is unknown if they were performed at a metabolic steady state, we included these studies as they typically used speeds at which similar populations were shown to run at a metabolic steady-state in other studies (e.g., [ 87 , 116 , 117 , 119 , 124 ]), or because the speed of the RE assessment was slower than the half-marathon speed (5.56 vs 5.86 m∙s −1 , respectively) [ 92 ], thus likely being at a metabolic steady-state, in particular on the treadmill due to the smaller influence of air drag.…”