Monday, June 30, 2008

Sodium Phosphate loading

There is an interesting discussion going on in wattage about Sodium Phosphate loading. Along with this pointer to a recent paper.

After SP loading mean power was greater than for P and C (C, 322+/-15W; P, 317+/-16W; SP, 347+/-19W; ANOVA, P<0.05) and time to complete the 16.1km was shorter than P, but not C (ANOVA, P<0.05). During the SP trial, relative to the P, mean changes were mean power output +9.8+/-8.0% (+/-95% confidence interval); time -3.0+/-2.9%. There was a tendency towards higher V O(2) after SP loading (ANOVA, P=0.07). Heart rate, V (E), RER and blood lactate concentration were not significantly affected by SP loading. Sodium phosphate loading significantly improved mean power output and 16.1km time-trial performance of trained cyclists under laboratory conditions with functional increases in oxygen uptake.

If I read that correctly, up to 9% power increase and 3% decrease in time. For a 16km TT we could assume about 20 minutes and 3% would be about 30 seconds.

Not that I want to give my secrets away :-) But I tried this for my "A" TT last year... The TT results where poor, but that was due to a flat... But my overall "performance" for the day was (I thought) very good. See here.

Now whether that was due to the Sodium Phosphate loading or to tapering for the race it is really hard to tell. I don't think the loading caused any problems. And I suspect that it did help.

On balance I'll be doing it again this year for specific "A" type TT events.