. 2021 May 3;160(4):1377–1387. doi: 10.1016/j.chest.2021.04.041

Table 1.

Arithmetic Mean, Geometric Mean, and Geometric SD of Eight Subjects at the End of Each Study Phase for P-Track (TSI Incorporated) Front, Side, and Back Particle Counts per Liter and Fluke (Fluke Corporation) Particle Counts per Liter for Particles >0.3 μm, 0.3 to 1.0 μm, and 1.0 to 5.0 μm

Time, min	Phase	P-Trak Measured Particles		Fluke Measured Particles
		Arithmetic Mean ± SD	Geometric Mean ± SD	Arithmetic Mean ± SD	Geometric Mean ± geometric SD
		Anterior Sensor		>0.3 μm
0	Start rest	849 ± 607	637 ± 2.3	77 ± 48	66 ± 1.8
5	End rest	971 ± 968	642 ± 2.6	90 ± 54	73 ± 2.1
	Predicted heart rate reserve
8	25%	925 ± 602	707 ± 2.5	173 ± 61	164 ± 1.4
11	50%	1,200 ± 472	1,125 ± 1.5	277 ± 102	261 ± 1.4^a
14	75%	1,862 ± 891	1,726 ± 1.5^a	1,007 ± 1,432	604 ± 2.6^a
17	100%	5,725 ± 6,895	3,702 ± 2.5^a	2,961 ± 5,340	1,213 ± 2.6^a
20	Cool-down	10,100 ± 15,875	5,148 ± 3.0^a	3,902 ± 6,606	1,605 ± 3.8^a
		Side Sensor		0.3-1.0 μm
0	Start rest	975 ± 628	708 ± 2.7	45 ± 36	35 ± 2.2
5	End rest	1,175 ± 759	935 ± 2.2	56 ± 36	42 ± 2.5
	Predicted heart rate reserve
8	25%	1,538 ± 833	1,365 ± 1.7	107 ± 52	98 ± 1.6
11	50%	2,513 ± 2,975	1,592 ± 2.7	172 ± 70	160 ± 1.5^a
14	75%	3,263 ± 2,590	2,633 ± 1.9^a	803 ± 1,346	385 ± 3.0^a
17	100%	6,388 ± 6,975	4,402 ± 2.4^a	2,547 ± 5,082	799 ± 4.4^a
20	Cool-down	11,706 ± 16,467	6,844 ± 2.7^a	3,388 ± 6,301	1095 ± 4.6^a
		Back Sensor		1.0-5.0 μm
0	Start rest	775 ± 548	519 ± 3.1	25 ± 16	21 ± 2.0
5	End rest	596 ± 448	447 ± 2.7	28 ± 14	24 ± 1.7
	Predicted heart rate reserve
8	25%	992 ± 891	684 ± 2.8	48 ± 17	45 ± 1.4
11	50%	1,417 ± 1,005	1,200 ± 1.8	80 ± 32	75 ± 1.5^a
14	75%	2,454 ± 1,530	2,116 ± 1.8^a	168 ± 97	147 ± 1.8^a
17	100%	4,225 ± 4,114	3,092 ± 2.2^a	369 ± 284	288 ± 2.1^a
20	Cool-down	10,150 ± 13,404	5,853 ± 2.8^a	470 ± 354	358 ± 2.3^a

Indicates significantly different at P < .05 from geometric mean at 0 minutes (start rest).