Traditional heating or series to exhaustion, which the most efficient for the improvement of the results?

In Bodybuilding (weight training) we confront many custos and legends related training variations and what to do before and after the sessions. A question often raised is the execution of stretching, heating or neither of them preceding practice. Today we discuss in greater detail the effects of the use of specific heating preceding the training session. Hypertrophy is a very important factor for people involved in sports, be they athletes from team sports like football, volleyball, to weightlifting athletes (Schoenfeld, 2010), especially if we take based on the mention of Maughan et al. (1983), citing a strong correlation between the cross-sectional area of muscle and muscle strength. The mechanical stress is a primary stimulus for muscle hypertrophy, but there is also convincing evidence that the metabolic stress is also able to contribute to muscle growth (Schoenfeld 2013). Previous studies using the Kaatsu (training with vascular restriction) showed interesting results regarding protein synthesis even using low overloads (FRY et al., 2010). The results were similar to the use of high loads (ABE et al., 2006).

Some factors may explain this effect of vascular occlusion: This method induces increased local fatigue (Phillips 2009) and the largest accumulation of the metabolite (Loenneke et al., 2010). These variables require the recruitment of type II fibers (Suga et al 2009, 2010;.. Takarada et al 2000a, b), which are highly hypertrophic (Campos et al., 2002). Some hypotheses are raised to explain why the metabolic stress can lead to increased recruitment of type II fibers: 1. The accumulation of intracellular H +, which restricts the function of the contractile muscle, promoting the recruitment of additional fiber type II (Debold 2012; Miller et al, 1996; 2000b Takarada et al.); 2. Local hypoxia, which leads to an increased activation of type II fibers in order to maintain the strength levels (Moritani et al 1992;. Sundberg 1994); 3.  Intracellular production of free radicals, which produces automatic response and an increased recruitment of fibers II hastening the onset of fatigue (Debold 2012).

The literature suggests that it is more important to a volume of training leading to exhaustion of the use of muscular high overloads (Burd et al 2010a, b; Krieger, 2010; Mitchell et al 2012; Rhea et al, 2002, 2003; Wolfe et al., 2004). Recently, Aguiar et al. (2015) promoted a very interesting study comparing the execution of a warming session to exhaustion preceding the training session and the conventional protocol. In both protocols participants performed 3 series with loads allowing perform 8-12 repetitions. What differentiated each protocol was heating, where the conventional protocol heated with a series of 12 repetitions with low load, while the protocol of a further series until exhaustion, performing heating with a range 20% load with 1RM performing many repetitions were possible. The authors evaluated the subjects before and after a protocol of 8 weeks of training, and there is no outside influence, controlled power and the subject could not have been supplementing it. Strength were evaluated (1RM), muscle area (cross-sectional area of muscle) of the rectus femoris, vastus, lateral vast, vast middle, and the work employed to perform the exercises. The results were reported significantly increased 1RM both conventional training (CT) and in training with heating until exhaustion (TAE) compared to the control group (CG), but with a significant difference between TC and TAE, and the second had best results. Of thier muscle cross-sectional area, the result was similar. Both training groups had significant improvements, but every muscle in the TAE group had statistical superiority in increasing muscle mass. About work index and total number of repetitions performed, the training group with heating until exhaustion also showed better results. Researchers highlighted two possible reasons for having achieved these results: 1- The number of repetitions in the heating performed in the training group with heating until exhaustion reached between 45-55, which would lead to greater recruitment of type II fibers, considering Schoenfeld et al. (2013), mentions on the implementation of repetitions to exhaustion using low overload causes increased recruitment of type II fibers. Achieving such a feat in the heating causes during exercise fatigue of type I fibers occurs more easily while maintaining the increased recruitment of type II fibers and consequently signal greater hypertrophy. 2- The greatest accumulation of metabolites leads to greater recruitment of type II fibers and increased signage will hypertrophy during heating. This hypothesis has been raised due to the results found with Kaatsu where using smaller loads and series to exhaustion, had higher concentration of metabolites and consequently type II fibers, also resulting in greater hypertrophy (Suga et al 2009, 2010; Takarada et al 2002).

Of thier improving muscular endurance, presented by the reduction of work index, it was not surprising result if we consider the findings of Campos et al (2002) and Goto et al (2004), who report that smaller loads and higher volume is more for efficient acquisition of resistance of muscle to use smaller volumes and higher loads.

Apparently the use of a series of warming up the exhaust is able to assist in increasing strength, endurance and muscle mass in a more pronounced way than the use of conventional protocol. New studies with other populations and using the muscle groups may claim the current view.