Table 4.

³¹P-MRS exercise testing results at baseline (B) and end-of-study (E) for each of the 3 exercise tests: 30 seconds at maximal intensity, 60 seconds at moderate intensity, and 5 × 30 seconds at moderate intensity each separated by 15 seconds of rest.

	Timepoint	30-s Test, mean ± SD	P	60-s Test, mean ± SD	P	5 × 30-s Test, mean ± SD	P
Change in pH afer exercise	B	0.32 ± 0.28	0.57	0.46 ± 0.26	0.96	0.30 ± 0.27	0.003
(rest pH-end exercise pH)	E	0.37 ± 0.43		0.45 ± 0.30		0.25 ± 0.26
Pi/PCr, ratio	B	1.30 ± 0.61	0.11	2.44 ± 1.20	0.03	2.48 ± 1.58	0.28
	E	1.17 ± 0.70		2.08 ± 1.12		2.33 ± 1.99
ATP produced by creatine	B	0.31 ± 0.10	0.08	0.20 ± 0.04	0.25	0.34 ± 0.11	0.11
kinase, mmol/L/min–¹	E	0.29 ± 0.12		0.19 ± 0.06		0.31 ± 0.13
ATP produced by anaerobic	B	0.69 ± 0.53	0.59	0.57 ± 0.33	0.23	0.92 ± 0.70	0.01
glycolysis, mmol/L/min–¹	E	0.65 ± 0.53		0.52 ± 0.33		0.80 ± 0.69
ATP produced by aerobic	B	0.30 ± 0.07	0.04	0.34 ± 0.14	0.24	0.23 ± 0.07	0.69
oxidation, mmol/L/min–¹	E	0.23 ± 0.11		0.31 ± 0.16		0.21 ± 0.08
ATP total produced by all	B	1.30 ± 0.64	0.13	1.11 ± 0.41	0.10	1.48 ± 0.82	0.02
pathways, mmol/L/min–¹	E	1.17 ± 0.75		1.02 ± 0.48		1.33 ± 0.84

³¹P-MRS: 31-Phosphorus Magnetic Resonance Spectroscopy; ATP: adenosine triphosphate; PCr: phosphocreatine; Pi: phosphate.