Engaging in sled training can be a fun and challenging exercise. It helps one to lose fat, gain muscle and tone as well. The benefits are there for both athletes and active lifestyle individuals.
Forewarning, a lot of the information in this article contains statistics and medical terms from a British study. Some of it might be hard to read. Need not to worry, take whatever it is you learn and understand.
In a recent study from Britain, weighted sled training male test subjects did five sets of two 20-meter sled pulls (the sled was loaded with a 75 percent of their body mass). The drag position had the participants facing the sled while moving backwards. There was an emphasis put on concentric muscle action in the sets. The men were then tested for hormone levels, markers for muscle damage and neuromuscular strength throughout the workout.
The results showed that neuromuscular strength as measured by a vertical jump was reduced for 1 hour after the workout, but it was recovered to baseline levels by 3 hours after the workout. The slight reduction in strength were due to depleted phosphocreatine and acid-based disruption as well as an accumulation in hydrogen ions. Neuromuscular strength was quickly recovered. The indications are that sled dragging using concentric contraction that are not significant and do not result in any muscle damage. A typical weight training session in a gym that includes the eccentric motion as well would be likely to produce more muscle damage with a longer recovery time. The lack of muscle damage was confirmed when no evidence of change in the biomarker for creatine kinase was measured.
After the sledding session there was a six-fold increase in blood lactate after the workout, indicating a large metabolic stress that could be effective for promoting fat loss. Lactate buildup is associated with a large elevation in growth hormone and IGF-1. When measured testosterone increased by 38 percent at 15 minutes post-workout. Testosterone was also elevated at 24 hours post-training, which could represent a rebound effect to aid recovery from intense training. Researchers suggest this is a favorable response that could improve subsequent motivation to train, increase competitive drive, and reduce fear. these are great advantages for those who wish to use this training exercise.
Researchers also found that cortisol was increased 54 percent at 15 minutes post-workout, but it declined below baseline at 3 hours, indicating an effective recovery.
Summing that all up; research suggests that sled training could lead to beneficial changes in body composition, without a major reduction in strength performance. Sled training can induce glycogen depletion if volume and intensity are high enough, while applying significant metabolic stress. However, since there was no evidence of muscle damage, glycogen resynthesis wouldn’t be hindered as long as athletes take advantage of the post-workout recovery period. A second competition or workout could be performed the same day with no pejorative results. This means that sled training holds many advantages for those who want to find an exercise they love and enjoy the many physical gains it has to offer.
West, D., et al. The Metabolic, Hormonal, Biomechanical, and Neuromuscular Function Responses to a Backward Sled Drag Training Session. Journal of Strength and Conditioning Research. 2013. Published Ahead of Print.