Search Results

You are looking at 1 - 2 of 2 items for

  • Author: Wilfried Kindermann x
Clear All Modify Search
Restricted access

Oliver Faude, Tim Meyer and Wilfried Kindermann

Purpose:

The work rate (WR) corresponding to ventilatory threshold (VT) is an appropriate intensity for regenerative and low-intensity training sessions. During incremental ramp exercise, VO2 increase lags behind WR increase. Traditionally, a VO2 time delay (t d) of 45 seconds is used to calculate the WR at VT from such tests. Considerable inaccuracies were observed when using this constant t d. Therefore, this study aimed at reinvestigating the temporal relationship between VO2 and WR at VT.

Methods:

20 subjects (VO2peak 49.9 to 72.6 mL · min–1 · kg–1) performed a ramp test in order to determine VT and a subsequent steady-state test during which WR was adjusted to elicit the VO2 corresponding to VT. The difference in WR and heart rate at VT was calculated between the ramp and the steady-state test (WRdiff, HRdiff) as well as the time delay corresponding to WRdiff during ramp exercise.

Results:

Mean values were t d = 85 ± 26 seconds (range 38 to 144), WRdiff = 45 ± 12 W (range 23 to 67), HRdiff = 1 ± 9 beats/min (range –21 to +15). The limits of agreement for the difference between WR at VT during ramp and steady-state exercise were ± 24 W. No signifi cant influence on t d, WRdiff, or HRdiff from differences in endurance capacity (VO2peak and VT; P > .10 for all correlations) or ramp increment (P = .26, .49, and .85, respectively) were observed.

Conclusion:

The wide ranges of t d, WRdiff, and HRdiff prevent the derivation of exact training guidelines from single-ramp tests. It is advisable to perform a steady-state test to exactly determine the WR corresponding to VT.

Restricted access

Markus Herrmann, Rima Obeid, Juergen Scharhag, Wilfried Kindermann and Wolfgang Herrmann

This study aimed to compare the vitamin B12 and folate status of recreational endurance athletes and inactive controls by modern biomarkers. In 72 athletes (38 ± 7 y) and 46 inactive controls (38 ± 9 y) serum levels of vitamin B12, methylmalonic acid (MMA), holotranscobalamin II (holoTC), folate, and homocysteine (Hcy) were measured. Vitamin B12 and folate levels of both groups were comparable, but athletes had higher median (25.−75. percentile) MMA [242 (196 to 324) versus 175 (141 to 266) nmol/L] and holoTC concentrations [67 (52 to 93) versus 55 (45 to 70) pmol/L] than controls. Hcy was slightly lower in athletes [9.2 (7.2 to 12.6) versus 10.8 (8.9 to 12.9) nmol/L]. In controls, we found the following correlations: vitamin B12 and MMA (r = −0.38), vitamin B12 and holoTC (r = 0.51), MMA and holoTC (r = −0.36). In athletes, MMA did not correlate with vitamin B12 and holoTC. Our data suggests an altered vitamin B12 metabolism in recreational athletes that needs further investigation.