Which Phases of the Stroke Cycle Are Propulsive in Front Crawl Swimming?

Figures & data

Table 1. Acceleration, velocity, and phase duration data for the 200 m maximum front crawl swim (mean ± standard deviation).

	SC1	SC2	SC3	SC4	Mean
Acceleration (m/s^2)
Entry (F = 1.3)	−0.04 ± 0.24	0.02 ± 0.17	0.10 ± 0.13	0.08 ± 0.14	0.04 ± 0.17
Pull (F = 1.4)	0.03 ± 0.31	0.14 ± 0.28	0.07 ± 0.35	−0.08 ± 0.25	0.04 ± 0.30
Push (F = 0.6)	0.18 ± 0.35	0.05 ± 0.38	0.06 ± 0.32	0.09 ± 0.29	0.09 ± 0.34
Recovery (F = 0.2)	−0.17 ± 0.25	−0.21 ± 0.34	−0.23 ± 0.30	−0.17 ± 0.21	−0.19 ± 0.27
Velocity (m/s)
Entry (F = 105.2*)	1.70 ± 0.04^b,d	1.53 ± 0.06^b,d	1.49 ± 0.08^b	1.46 ± 0.06^b	1.55 ± 0.06^b,d
Pull (F = 32.8*)	1.62 ± 0.06^a,c,d	1.48 ± 0.05^a,c,d	1.45 ± 0.08^a,c,d	1.42 ± 0.06^a,c	1.49 ± 0.06^a,c,d
Push (F = 159.7*)	1.70 ± 0.04^b,d	1.53 ± 0.05^b	1.49 ± 0.06^b	1.46 ± 0.06^b	1.55 ± 0.05^b
Recovery (F = 53.5*)	1.66 ± 0.06^a,b,c	1.51 ± 0.07^a,b	1.48 ± 0.09^b	1.45 ± 0.06	1.53 ± 0.07^a,b
Maximum Velocity (m/s)
Entry (F = 62.0*)	1.81 ± 0.07^b	1.66 ± 0.09^b,d	1.61 ± 0.10	1.58 ± 0.08	1.66 ± 0.08^b
Pull (F = 29.3*)	1.72 ± 0.07^a,d	1.57 ± 0.07^a,c	1.55 ± 0.10	1.50 ± 0.08	1.58 ± 0.08^a,c,d
Push (F = 77.9*)	1.79 ± 0.05	1.64 ± 0.06^b	1.58 ± 0.07	1.56 ± 0.06	1.64 ± 0.06^b
Recovery (F = 51.8*)	1.81 ± 0.07^b	1.62 ± 0.11^a	1.60 ± 0.12	1.55 ± 0.08	1.65 ± 0.10^b
Minimum Velocity (m/s)
Entry (F = 46.2*)	1.58 ± 0.06^b	1.39 ± 0.05	1.36 ± 0.07	1.35 ± 0.07	1.42 ± 0.06
Pull (F = 17.3*)	1.51 ± 0.07^a,c	1.40 ± 0.05	1.34 ± 0.08	1.35 ± 0.06	1.40 ± 0.06^c
Push (F = 68.9*)	1.61 ± 0.06^b,d	1.44 ± 0.07	1.38 ± 0.07	1.37 ± 0.06	1.45 ± 0.07^b,d
Recovery (F = 24.3*)	1.52 ± 0.07^c	1.39 ± 0.06	1.36 ± 0.07	1.35 ± 0.04	1.41 ± 0.06^c
Phase Durations (percentage of stroke cycle)
Entry (F = 1.1*)	32.8 ± 4.9^b,c,d	35.1 ± 7.1^b,c,d	33.6 ± 5.4^b,c,d	34.3 ± 4.4^b,c,d	34.0 ± 5.4^b,c,d
Pull (F = 2.1*)	18.5 ± 2.8^a,d	18.6 ± 4.0^a,d	19.9 ± 3.7^a	18.7 ± 1.9^a,c,d	18.9 ± 3.1^a,c,d
Push (F = 3.6*)	21.6 ± 2.9^a,d	21.9 ± 4.0^a	22.3 ± 3.3^a	23.5 ± 3.3^a,b	22.3 ± 3.4^a,b
Recovery (F = 14.1*)	26.1 ± 3.6^a,b,c	24.4 ± 2.5^a,b	24.3 ± 1.8^a	23.4 ± 2.2^a,b	24.5 ± 2.5^a,b

SC: stroke cycle. For each phase, the F values for the overall statistical comparisons between the four stroke cycles are shown in brackets. *Indicates the presence of significant differences.

For each variable, statistically significant differences between stroke cycle phases within a single stroke cycle, are noted above as follows: ^asignificantly different from entry phase; ^bsignificantly different from pull phase; ^csignificantly different from push phase; ^dsignificantly different from recovery phase.

Figure 1. Velocity of the CM of a single swimmer throughout a stroke cycle. The start points of each of the four phases of the stroke cycle are indicated in the graph for both the right arm (RA, continuous vertical lines) and the left arm (LA, dashed vertical lines). The periods of overlaps between the phases of the two arms are indicated at the bottom of the graph.

Table 2. Phase overlaps (mean ± standard deviation).

	SC1	SC2	SC3	SC4	Mean
Percentage (%) of ENTRY phase overlapping with opposite arm:
Pull (F = 1.4)	9.5 ± 5.1^c,d	12.7 ± 8.2^c,d	11.0 ± 6.7^c	10.4 ± 6.8^c,d	10.9 ± 6.7^c,d
Push (F = 1.9)	59.7 ± 13.1^b,d	60.9 ± 18.6^b,d	67.1 ± 17.4^b,d	67.1 ± 14.3^b,d	63.7 ± 15.8^b,d
Recovery (F = 4.2*)	30.8 ± 11.3^b,c	26.4 ± 13.8^b,c	21.9 ± 13.7^,c	22.6 ± 9.4^b,c	25.4 ± 12.0^b,c
Percentage (%) of PULL phase overlapping with opposite arm:
Entry (χ^2 = 4.1)	18.9 ± 11.2^a,c,d	28.8 ± 25.1^c	21.6 ± 17.3^c,d	21.8 ± 17.2^c,d	22.8 ± 17.7^c,d
Push (χ^2 = 5.8)	0.5 ± 1.5^a,d	2.5 ± 5.3^a,d	0.5 ± 1.5^a,d	1.1 ± 2.4^a,d	1.1 ± 2.7^a,d
Recovery (χ^2 = 4.8)	80.6 ± 10.9^a,c	68.7 ± 24.2^c	77.9 ± 17.1^a,c	77.1 ± 16.9^a,c	76.1 ± 17.3^a,c
Percentage (%) of PUSH phase overlapping with opposite arm:
Entry (χ^2 = 7.3)	89.0 ± 9.7^b,d	92.8 ± 8.4^b,d	96.6 ± 5.0^b,d	95.7 ± 6.0^b,d	93.5 ± 7.3^b,d
Pull (χ^2 = 5.8)	0.4 ± 1.3^a	2.1 ± 4.9^a	0.4 ± 1.3^a	0.8 ± 1.8^a	0.9 ± 2.3^a
Recovery (χ^2 = 7.5)	10.6 ± 9.4^a	5.1 ± 6.3^a	2.9 ± 4.9^a	3.5 ± 5.0^a	5.5 ± 6.4^a
Percentage (%) of RECOVERY phase overlapping with opposite arm:
Entry (F = 0.4)	38.1 ± 16.9^c	41.7 ± 27.8^c	32.7 ± 22.8^c	34.2 ± 17.9^c	36.7 ± 21.3^c
Pull (F = 1.3)	54.9 ± 13.6^c	53.8 ± 25.5^c	64.3 ± 22.2^c	62.4 ± 16.9^c	58.9 ± 19.6^c
Push (χ^2 = 2.9)	7.1 ± 6.8^a,b	4.6 ± 5.8^a,b	2.9 ± 5.3^a,b	3.4 ± 5.3^a,b	4.5 ± 5.8^a,b

SC: stroke cycle. For each phase, the F values for the overall statistical comparisons between the four stroke cycles are shown in brackets. *Indicates the presence of significant differences.

For each variable, statistically significant differences between stroke cycle phases within a single stroke cycle, are noted above as follows: ^asignificantly different from entry phase; ^bsignificantly different from overlap with opposite arm pull phase; ^csignificantly different from overlap with opposite arm push phase; ^dsignificantly different from overlap with opposite arm recovery phase.

Table 3. Acceleration data (m/s²) for overlapping phases of the opposite arms during the 200 m maximum front crawl swim (mean ± standard deviation).

	SC1	SC2	SC3	SC4	Mean
Phases of opposite arms overlapping
Entry/Pull	1.02 ± 1.28	1.10 ± 0.84	0.81 ± 1.08	0.47 ± 0.83	0.85 ± 1.01
Entry/Push	0.06 ± 0.32	0.04 ± 0.44	0.10 ± 0.37	0.07 ± 0.29	0.07 ± 0.35
Entry/Recovery	−0.44 ± 0.81	−0.30 ± 0.90	−0.03 ± 1.01	−0.20 ± 0.76	−0.24 ± 0.87
Pull/Push	1.17^a	0.10 ± 0.26	2.10^a	1.12 ± 1.18	1.12 ± 0.72
Pull/Recovery	−0.03 ± 0.81	−0.17 ± 0.62	−0.19 ± 0.36	−0.22 ± 0.48	−0.15 ± 0.57
Push/Recovery	1.08 ± 1.30	0.30 ± 1.01	−0.91 ± 1.73	1.30 ± 0.71	0.19 ± 1.19

SC: Stroke Cycle.

^aStandard deviation not applicable for these SCs, because only one swimmer presented these phase overlaps.