Excessive joint loading has been associated with the onset and an increased rate of progression of osteoarthritis, but little is known about the effects of exercise loading on synovial fluid (SF) composition and chondrocytes viability. The purpose of this study was to load intact knee joints with two types of controlled maximal muscular contractions (low, and high intensity exercise) and identify changes in synovial fluid protein composition and chondrocyte death. We found that:​

1. Chondrocytes are well protected to withstand very high loads over a short period of time, and maximal endurance loading.
2. High intensity, short duration exercise did not change total protein concentration in SF. However, it decreased the number of identifiable proteins.
3. Low intensity, long duration exercise did not change total protein concentration in the SF, but it increased the number of identifiable proteins.