What is likely to occur when rest periods are shortened from 2 minutes to 1 minute in a 10RM circuit weight training program?

When rest periods in a circuit weight training program are shortened from 2 minutes to 1 minute, the most likely outcome is an increase in lactate levels. This occurs because shorter rest intervals do not allow enough time for the body to clear lactate that is produced during high-intensity activities.

During high-intensity strength training, especially when performing a 10 repetition maximum (10RM), the body relies on anaerobic metabolism. As the muscles work hard, they produce lactate as a byproduct of anaerobic glycolysis. When rest is minimized, the continuous demand for energy leads to an accumulation of lactate in the blood, which can contribute to the sensation of fatigue and discomfort in the muscles. Therefore, shorter rest periods increase overall metabolic stress and cause a rise in lactate levels as the body struggles to manage the byproducts of intense exercise efficiently.

While changes in pH, creatine kinase levels, and heart rate are all important physiological considerations, they do not directly reflect the immediate metabolic state related to anaerobic activity as clearly as lactate levels do in this context.