We analyze and present different strategies to adapt the load in transactional memory systems based on contention. Our experimental results show a substantial overall improvement for our best performing strategies QuickAdapter and AbortBackoff on the throughput compared to the best existing contention management policies (without load adaption). Opposed to prior work our load adapting schemes are simple and fully distributed, while maintaining the same throughput rate. Our theoretical analysis gives insights into the usefulness of load adaption schemes. We show a constant expected speed-up compared to systems without load adaption in several important scenarios, but also illustrate that the worst-case behavior can result in an exponential increase in the running time.