Table 1.

Mean resting and exercising ST and PCr resynthesis measures

	Resting	Exercising	Paired-Samples Difference*	P†
ST, n = 9
[Pi], mM	3.37 ± 0.18	10.23 ± 1.10	6.9 ± 1.1	<0.001
T1′, s	4.5 ± 0.1	4.8 ± 0.3	0.3 ± 0.3	0.376
k′, min−1	2.98 ± 0.35	2.44 ± 0.16	−0.54 ± 0.39	0.204
VPi-ATP, mM/min	9.8 ± 0.9	25.0 ± 2.9	15.1 ± 3.5	0.003
PCr resynthesis, n = 11
[PCr], mM	32.9 ± 1.0	23.5 ± 1.2	−9.3 ± 1.2	<0.001
VATP, mM/min	‡	16.5 ± 1.8		ND

ST, saturation transfer; P_i, inorganic phosphate; T₁′, apparent longitudinal relaxation time of P_i in the presence of saturation of the γ-ATP resonance; k′, first-order rate constant; V_Pi-ATP, rate of P_i→ATP flux; [PCr], concentration of phosphocreatine; V_ATP, suprabasal oxidative rate of ATP synthesis determined from immediate end of exercise PCr resynthesis; ND, not determined.

Values are means ± SE. Data from volunteers in group B were averaged to provide one value per person to avoid inappropriate weighting.

^*Paired-samples difference (exercising-resting).

^†Paired-samples t-test to test for significant differences between rest and exercising conditions.

^‡For comparison with exercising, this is 0.0 because V_ATP reflects suprabasal oxidative ATP synthesis. The net rate of basal oxidative ATP turnover is thought to be approximately 0.5 mM/min (16).