Submaximal exercise testing is frequently used by health fitness professionals to estimate maximal oxygen uptake. It is essential for the health fitness professional to know how accurate and which submaximal exercise protocol is appropriate for subjects. The purpose of this study is to examine the accuracy of the Balke-Ware, YMCA, and Astrand-Ryhming submaximal exercise tests compared to direct measurement of peak oxygen uptake. Because age predicted heart rate (HR) is used to determine results, a secondary purpose was to examine the differences in measured HRs and the traditional method of predicting HRmax of 220 –age to the newer method of [208 – (.7)(age)] (Tananka, 2001). Ten NCAA Division III male athletes volunteered for this study. A repeated measures study design examined differences in the peak oxygen uptake (PVO2) results between the four protocols. A medical graphic V02000 gas analyzer directly measured peak oxygen uptake (MPVO2) during a graded exercise test (GXT) using the Bruce treadmill protocol. The order of tests was randomized, and there was at least a 24-hour interval between tests. Formulas and tables specific to the submaximal protocols determined maximal oxygen uptake results. The maximal GXT Bruce protocol value was the criteria for peak oxygen uptake. One-sample t-tests revealed no significant differences (p > 0.05) between MPVO2 (72.1 ± 6.1 ml/kg/min) and the Astrand-Rhyming submaximal bike (ARB) (69.2 ± 9.8) or the Balke-Ware submaximal treadmill (BWT) (68 ± 8.3) tests. However, there was a significantly lower (p = 0.003) maximal oxygen uptake prediction from the YMCA submaximal bike test (56 ± 12.4) compared to the MPV02 results. In conclusion, the ARB and the BWT submaximal tests are good predictors of peak oxygen uptake and the YMCAB provides an underestimate of MPV02. In addition, the newer method of predicting HRmax (193bpm) was a better predictor the than the traditional method (199bpm) compared the measure peak HR (195bpm). Results may allow health fitness professionals to make informed decisions on which submaximal exercise test would be the most accurate and appropriate test.Keyword(s): exercise/fitness, measurement/evaluation