Bovine colostrum supplementation during endurance running training improves recovery, but not performance.
This study examined the effect of supplementation with concentrated bovine colostrum protein powder (intact) on plasma insulin-like growth factor I (IGF-I) concentrations, endurance running performance and recovery. Thirty physically active males completed 8 weeks of running training whilst consuming 60 g x day(-1) of intact powder (n=17) or a concentrated whey protein powder placebo (n=13) in a randomised, double-blind, parallel design. Plasma IGF-I concentrations were measured prior to subjects performing two (approximately 30 min) incremental treadmill running tests to exhaustion (RUN1 and RUN2) separated by 20 min of passive recovery at Weeks 0. 4 and 8. Plasma IGF-I concentrations showed little change in either group (p=0.83). Effective peak running speed (PRSE; i.e. equivalent of peak power) during RUN1 was not different between groups at Week 0 (p>0.99), and had increased by a similar amount in both groups by Week 4 (mean+/-SD, intact 2.2+/-4.0%, placebo 3.2+/-3.3%; 95% confidence interval [95% CI 15.7 to -13.7%; p=0.89) and Week 8 (intact 3.6+/-5.6%, placebo 3.4+/-4.4 %; 95% CI -100.0 to 100.0%; p>0.99). PRSE was less in both groups during RUN2 (p<0.05), but was not significantly different between groups at Week 0 (p>0.99). PRSE during RUN2 tended to have increased more in the placebo group by Week 4 (intact 1.8+/-4.8%, placebo 4.2+/-3.9%; 95% CI 0.2 to -5 0%; p=0.07), but the intact group had increased PRSE significantly more by Week 8 (intact 4.6+/-6.1%, placebo 2.0+/-4.5%; 95% Cl 0.0 to 5.2%; p=0.05). resulting in a significantly faster PRSE (p=0.003). We conclude that supplementation with intact powder did not increase plasma IGF-I concentrations or improve performance during an initial bout of incremental running to exhaustion in our sample. However, performance during a second bout of exercise may be improved by as much as 5.2% in the average subject after 8 weeks of supplementation, possibly due to an enhancement of recovery.
Centre for Research in Education and Sports Science, School of Physical Education Exercise and Sport Studies, University of South Australia, Adelaide.
J D
JD
Buckley
M J
MJ
Abbott
G D
GD
Brinkworth
P B D
PB
Whyte
D000293:Adolescent; D000328:Adult; D003126:Colostrum; D004044:Dietary Proteins; D019587:Dietary Supplements; D004311:Double-Blind Method; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000032:analysis*; D008297:Male; D010807:Physical Endurance; D012420:Running; D013647:Task Performance and Analysis
D004044:Dietary Proteins; D007334:Insulin-Like Growth Factor I