Exercise-induced lactate responses in Multiple Sclerosis: A retrospective analysis

Abstract

BACKGROUND: Persons with Multiple Sclerosis have elevated resting serum lactate concentrations compared to healthy controls (HC). OBJECTIVE: To evaluate lactate concentrations during acute exercise and/or following training in MS compared to HC. METHODS: In this retrospective study, blood lactate concentrations (mmol/l) originating from two previous studies were analyzed. Lactate concentrations originated from acute submaximal (MSsubmax; HC, n = 11; MS, n = 32) or maximal (MSmax; HC, n = 20; MS, n = 24) exercise tests and following a 24-week mild to moderate intensity (MSsubmax, n = 12) or 12-week high intensity interval (MSmax, n = 13) exercise intervention. RESULTS: Under submaximal conditions in MS and compared to HC, lactaterest (MS: 2.7 +/- 0.6 vs HC: 2.3 +/- 0.7 was significantly (p < 0.05) elevated. After 24 weeks of mild-to-moderate-intensity exercise training and compared to PRE-values, lactate(bout2) (2.5 +/- 0.7 vs 3.4 +/- 1.1) significantly (p < 0.05) decreased during submaximal testing in MSsubmax. Under maximal conditions, lactatestart (2.3 +/- 1.0 vs 1.7 +/- 0.9) was significantly (p > 0.05) elevated in MS. Twelve weeks of high intensity interval training did not improve this (p > 0.05). CONCLUSIONS: Under the conditions of this retrospective analysis we conclude that lactate concentrations during acute submaximal and maximal exercise in persons with MS are similar compared to healthy controls. Moderate intensity exercise therapy appeared to improve lactate accumulation but high intensity exercise therapy did not.