Fig 1.
Experimental set up with the new timing methodology combining two speed guns synchronized.
See methods for details.
Table 1.
Reliability of some metabolic power variables collected with the new timing methodology and timing gates during sprints with and without change of direction.
Table 2.
Non-adjusted and change of direction-time-adjusted straight-line distances.
Fig 2.
Estimated energy expenditure of sprints with (45° or 90°) or without (i.e., straight-line, SL) one change of direction (COD).
90°25: 25-m sprint with one 90°-COD. The upper panel represents the standardized difference (Std Diff) between COD- and SL sprints. Since 90°25 vs. 20-m SL sprints could not be properly compared (i.e., differences in both running time and distance), their standardized difference (black circle) was not provided. The number of ‘*’ and ‘†’ refers to possible, likely, very likely and almost certain between-sprints differences versus the 45°-COD sprint trial, and within-sprint differences vs. the acceleration phases, respectively. The associated number refers to the magnitude of the difference, with 1 standing for small, 2 for moderate, 3 for large and 4 for very large magnitude.
Fig 3.
Relationship between acceleration and metabolic power.
Fig 4.
Electromyography amplitude (RMS) of 2 muscles during sprints with (45° or 90°) or without (i.e., straight-line, SL) one change of direction (COD).
The upper panel concerns the vastus lateralis muscle and the lower panel, the biceps femoris muscle. 90°25: 25-m sprint with one 90°-COD. The number of ‘*’ and ‘†’ refers to possible, likely, very likely and almost certain difference versus straight-line and 45°-COD sprints, respectively. The associated number refers to the magnitude of the difference, with 1 standing for small, 2 for moderate, 3 for large and 4 for very large magnitude.
Fig 5.
Electromyography amplitude (RMS) of vastus lateralis and biceps femoris muscles and speed profiles during sprints with (45° or 90°) or without (i.e., straight-line, SL) one change of direction (COD).
90°25: 25-m sprint with one 90°-COD. The medial panel represents the standardized difference (Std Diff) of RMS between COD- and SL sprints. The number of ‘*’ and ‘†’ refers to possible, likely, very likely and almost certain difference versus straight-line and 45°-COD sprints, respectively.
Fig 6.
Metabolic power/electromyography amplitude (RMS) ratio of sprints with (45° or 90°) or without (i.e., straight-line (SL)) one change of direction (COD).
90°25: 25-m sprint with one 90°-COD; BF: biceps femoris; VL: vastus lateralis. The number of ‘*’ and ‘†’ refers to possible, likely, very likely and almost certain difference versus straight-line and 45°-COD sprints, respectively. The associated numbers represent the magnitude of the standardized difference, with 1 standing for small, 2 for moderate, 3 for large and 4 for very large magnitude.
Fig 7.
Metabolic power/electromyography amplitude (RMS) ratio during the different phases of sprints with (45° or 90°) or without (i.e., straight-line (SL)) one change of direction (COD).
90°25: 25-m sprint with one 90°-COD; BF: biceps femoris; VL: vastus lateralis. The number of ‘*’ and ‘†’ refers to possible, likely, very likely and almost certain difference versus straight-line and 45°-COD sprints, respectively. The associated numbers represent the magnitude of the standardized difference, with 1 standing for small, 2 for moderate, 3 for large and 4 for very large magnitude.
Table 3.
Running variables during sprints with and without changes of direction.