The Lusternik-Schniremann-category and the fundamental group.

link: http://arxiv.org/abs/0909.4567
Abstract

We prove that $$ \cat X\le cd(\pi_1(X))+\bigg\lceil\frac{\dim
X-1}{2}\bigg\rceil$$ for every CW complex $X$ where $cd(\pi_1(X))$ denotes the
cohomological dimension of the fundamental group of $X$.