Metabolic demands of "junkyard" training: pushing and pulling a motor vehicle
Berning, JM, Adams, KJ, Climstein, M & Stamford, BA 2007, 'Metabolic demands of "junkyard" training: pushing and pulling a motor vehicle', Journal of Strength and Conditioning Research, vol. 21, no. 3, pp. 853-856.
Junkyard training involves heavy, cumbersome implements and nontraditional movement patterns for unique training of athletes. This study assessed the metabolic demands of pushing and pulling a 1,960-kg motor vehicle (MV) 400 m in an all-out maximal effort. Six male, strength-trained athletes (29 +/- 5 years; 89 +/- 12 kg) completed 3 sessions. Sessions 1 and 2 were randomly assigned and entailed either pushing or pulling the MV. Oxygen consumption (VO(2)) and heart rate (HR) were measured continuously. Blood lactate was sampled immediately prior to and 5 minutes after sessions 1 and 2. Vertical jump was assessed immediately prior to and after sessions 1 and 2. During session 3 a treadmill VO(2)max test was conducted. No significant differences (p < 0.05) in VO(2), HR, or blood lactate occurred between pushing and pulling efforts. VO(2) and HR peaked in the first 100 m, and from 100 m on, VO(2) and HR averaged 65% and 96% of treadmill maximum values (VO(2)max = 50.3 ml x kg(-1) x min(-1); HRmax = 194 b x min(-1)). Blood lactate response from the push and pull averaged 15.6 mmol.L(-1), representing 131% of the maximal treadmill running value. Vertical jump decreased significantly pre to post in both conditions (mean = -10.1 cm, 17%). All subjects experienced dizziness and nausea. In conclusion, a 400-m MV push or pull is an exhausting training technique that requires a very high anaerobic energy output and should be considered an advanced form of training. Strength coaches must be aware of the ultra-high metabolic and neuromuscular stresses that can be imposed by this type of training and take these factors into consideration when plotting individualized training and recovery strategies.