Subway Surfers wrote:
But was Hb measured as a weight/mass or as a %? It sounds like the muscle memory (or long term residual) findings with steroids. I wouldn't dismiss TTE so quickly though.
I think they measured only Hb level and not total Hb, which still could be calculated from blood volume even when the authors are of the opinion that the volume measurement method is unreliable. About TTE, I am not dismissing the TTE test results, but only questioning what it actually tells about performance, clearly something because sham group saw no improvement. When one compares the placebo vs. reinfusion groups, it is also crucial that nobody knows in which group they are, and I can recall the following concerns being voiced:
- The sham protocol has been questioned as the control group received 50 ml of saline and a subject could notice the difference to 900 ml of blood because the "feel" of being infused 850 ml might've been significantly different even when they were blinded and listening to music.
- Athletes training up to a 10000 km annually could have a good sense about their capabilities and noticed even a small difference in performance quickly. In either case, just knowing being "blood doped" raises questions about placebo effect.
In addition, there is no clear reason for the Vo2max not returning to the control level in 16 when Hb had returned to baseline. The authors speculate some sort of training adaptation, but it is equally plausible that the baseline figure (79.5) is measured too low to begin with when the subjects hadn't accustomed to threadmill running in which case the measured Vo2Max improvement is dubious, which is line with the observation that TTE performance wasn't better after 16 weeks when Vo2Max was.
From the 1972 Swedish reinfusion paper (Ekblom et al) to the 2018 Kenyan study (Haile et al), Vo2max pretty much returns to baseline in weeks and months after the treatment, so the observation here is a strange anomaly.