Carrying a backpack imposes stress on the back and lower limbs. In Reserve Officer Training Unit (ROTU), carrying a backpack is a requirement. It is included in the training drafted by the Malaysian Armed Forces. This study examined the effects of weight training on core strength, balance and jumping mechanics in 20 female ROTU cadets (Backpack group = 10, Control group = 10). Both groups underwent six weeks of physical training twice a week, performing a 2.4 km run, three sets of jumping jacks (20 reps each set) and three sets of squats (10 reps each set). During physical training, the Backpack group carried a military issue backpack with a total weight of 7 kg, while the Control group carried nothing. Four tests were conducted prior and after the training sessions which were, Modified Plank test to assess core strength; Balance Error Scoring System test to assess static balance; Star Excursion Balance test to assess dynamic balance and Drop Vertical Jump test to assess the jumping mechanics through the evaluation of Frontal Plane Projection Angle (FPPA) of the knee joint. There were no statistically significant differences in core strength (p-value = 0.353), static balance (p-value=0.458) and knee FPPA (p-value=0.681) when comparing between the two groups post-training. These results suggest that six weeks of training with a 7 kg-backpack does not have any major effects on the core strength, static and dynamic balance, and jumping mechanics of female ROTU cadets.