Placebo (n=6) | LHTL(+) (n=5) | LHTL(−) (n=5) | ||||
---|---|---|---|---|---|---|
Baseline | W4 | Baseline | W4 | Baseline | W4 | |
Submaximal O2 uptake | ||||||
VO2 at 150 W (l/min) | 2472±288 | 2447±170 | 2438±160 | 2351±83 | 2409±147 | 2366±186 |
Isovolumic haemodilution | – | 2396±212 | – | 2392±167 | – | 2332±218 |
VO2 at 200 W (l/min) | 3007±212† | 3015±148† | 3043±158 | 2957±177 | 3097±106 | 3005±91 |
Isovolumic haemodilution | – | 2998±313 | – | 2937±165 | – | 3022±138 |
Maximal O2 uptake and workload | ||||||
VO2max (ml/min) | 4948±446† | 5050±485† | 4924±582 | 4958±650 | 4557±726 | 4521±676 |
Isovolumic haemodilution | – | 4797±504 | – | 4672±583 | – | 4536±722 |
VO2max (ml/min/kg) | 70.8±5.3 | 72.3±6.0 | 73.5±2.9 | 74.3±4.8 | 65.1±4.8 | 66.5±5.5 |
Isovolumic haemodilution | – | 68.6±5.2** | – | 70.0±4.0** | – | 66.6±4.6 |
Maximal workload (W) | 411±23† | 422±28† | 412±50 | 432±49* | 398±72 | 394±62 |
Isovolumic haemodilution | – | 412±29 | – | 406±48** | – | 386±61 |
Total haemoglobin mass | ||||||
Hbmass (g) | 984±98† | 971±80† | 928±92 | 970±93* | 933±219 | 908±225 |
Hbmass (g/kg) | 14.06±0.76 | 13.88±0.60 | 13.87±0.97 | 14.58±0.95* | 13.14±1.00 | 13.12±1.15 |
Values are means±SD. Within the live high–train low (LHTL) group of 10 athletes, LHTL(+) and LHTL(−), respectively, refer to the subgroups of ‘responders’ and ‘non-responders’, that is, the athletes who did (or did not) increase their total haemoglobin mass (Hbmass) following 4 weeks of LHTL (W4). Isovolumic haemodilution was performed at W4, after the first incremental test had been completed. LHTL(+) subjects were isovolumically haemodiluted by means of phlebotomy and plasma volume expander (PVX) infusion, whereas LHTL(−) and placebo subjects received PVX infusion only. Hbmass, total haemoglobin mass (absolute and adjusted to body weight); VO2max, maximal O2 uptake (absolute and adjusted to body weight); maximal workload (Wmax) was calculated as: Wmax=Wcompl+25×(t/60), where Wcompl is the last workload completed, t is seconds that the final, not completed workload was sustained and 25 (W) is the increment in workload. For VO2 at 200 W, n=4 for LHTL(−).
*p<0.05 vs baseline, **p<0.05 vs W4.
†These data are reproduced from our previous report26 for the sake of clarity.