Abstract

The purpose of this study was to develop a simple assessment of lactate threshold (LT) in older people. Two-hundreds and nine subjects, aged 65 to 90 years old, performed a bench stepping test by means of a 20 cm bench at 10 to 35 ascends per minute of the stepping rate. In 52 of 209 subjects, we determined the metabolic equivalents corresponding to exercise intensity of which lactate (LA) increased 0.1, 0.2, 0.3, 0.4, 0.5 and 1 mmol/l from baseline level, LA corresponding to the baseline level and 2 mmol/l (METs@LAr+0.1, METs@LAr+0.2, METs@LAr+0.3, METs@LAr+0.4, METs@LAr+0.5, METs@LAr+1, METs@LAr and METs@LA2), in addition to LT. We calucurated exercise intensity equivalent to fixed LA levels by both a standard aseessment using a liner regression between exercise intensity (log- exercise inetsnity) and LA (log-LA) ranged above LT, and a simple assessment using a liner regression between log-exercise inetsnity and log-LA ranged bellow and above 2 mmol/l of LA. Using the standard assessment, no significant difference was confirmed between METs@LAr+0.1 (4.7 +/- 0.8 METs) and LT (4.6 +/- 0.7 METs). In regard to METs corresponding to other LA, using the standard assessment, METs@LAr (4.5 +/- 0.8 METs) was significantly lower (p<0.05), and the rest (4.8 +/- 0.8 - 5.6 +/- 0.8 METs) were significantly higher (p<0.01), compared with LT. There was no significant difference between METs@LAr+0.1 determined using standard assessment and simple assessment (4.6 +/- 0.9 METs). Also METs@LAr+0.1 determined by the simple assessment had high correlation and good limit agreement with LT (r=0.900, p<0.001 and 0.0 +/- 0.8 METs), as well as METs@LAr+0.1 determined by the standard assessment (r=0.930, p<0.001 and 0.0 +/- 0.6 METs). In 90% of men and 92% of women, LA reached 2 mmol/l at an intensity of 20, 25 or 30 ascends/minute. The method of evaluating exercise intensity corresponding to 0.1 mmol/l above resting level of LA using a stepping rate of 15, 20, 25 and 30 ascends/minute on a 20 cm platform, taking LA of 2 mmol/l as the termination criteria, can be considered valid as a simple assessment of LT in older individuals. Verf.-Referat