The purpose of this study was to assess if supervised, low intensity training would improve aerobic capacity and body composition in sixth graders. Twelve sixth graders walk-trained at approximately 50% of their maximal heart rate, four to five days/week for 12 weeks; beginning with an average of 10 miles/week and increasing to about 27 miles/week (Experimental group [E]). Six subjects of similar age volunteered to be controls (Control group [C]). Baseline and post?training measurements included: height (cm), body weight (kg), sum of skinfolds at six sites (mm), and maximal oxygen consumption (VO₂max; ml·kg^-1·min^-1). Three-day dietary records were also collected at pre-, mid-, and post-training to assess dietary changes that may have occurred during the study. There were significant increases (p < 0.05) from baseline to post-training in both groups in height and body weight. There was a significant interaction in the sum of skinfolds: E decreased 10.3% (p < 0.05) and C increased 2.3% (p > 0.05). There were no significant differences between groups in relative VO₂max (ml·kg^-1min^-1) from baseline to post-training. C consumed significantly more total kilojoules (11,577 ± 3883 [C]; 7431 ± 2523 [E]) and more total grams of carbohydrate (392 ± 403 [C]; 227 ± 48 [E]) and fat (93 ± 97 [C]; 62 ± 29 [E]) than E, post-training. C also consumed significantly more total grams of protein than E pre-training (95 ± 99 [C]; 74 ± 21 [E]). In conclusion, walk-training elicited a significant decrease in sum of skinfolds with no change in relative VO₂max. Furthermore, no dietary changes were observed in the experimental group as a result of the training.