Coach Education Resources
Train Less, Keep More
More is better" is aimed at the wrong question. Building a quality and keeping one are different jobs: more volume does build more, with diminishing returns, but you can hold what you've earned on about a third of the work, as long as the weight stays heavy.
Does U18 and U20 Success Correlate with Success at Senior Level?
Both male and female athletes who are more successful in young age categories (U18 and U20) were more likely to achieve success as a senior than less successful young athletes. Female athletes who were successful when young were more likely to maintain athletic success as a senior when compared to young males. A significant proportion of senior athletes (both male and female) were not successful in any of the young age categories.

