Home

The Practical Scientist - Part IV

by: 
Jamie Hale

In the previous additions of The Practical Scientist I have reviewed Nutrition studies. In this addition I will take a look at a study that focuses on exercise. The purpose of this article is to focus on strength and power gains from either complete cessation of training (DTR) or a tapering period (TAP). The study I am reviewing here also investigated circulating anabolic/catabolic hormones, but we will only look at the effects on strength and power in this article.



Some Key points from Detraining and Tapering Effects on Hormonal Responses and Strength Performance by Izquierdo M and colleagues.

Periodized strength training typically incorporates a taper phase to reduce accumulated fatigue. It is believed that the taper enhances performance by allowing greater recovery. Short-term reduction of the strength training volume while the intensity is kept high is a well-known coaching practice used to peak performance. However, a marked reduction of training intensity and volume, or complete training cessation, could bring about a partial or complete loss of recently acquired training-induced increases.

Decreased strength performance (7-12%) has been shown after short-term periods (4-8 weeks) of training cessation or periods of reduced training. On the contrary, other studies have shown that previously untrained or recreationally trained athletes can maintain or suffer only a slightly decrement in their neuromuscular performance during short periods (2-3 weeks) of training cessation. Recently, Andersen et al. reported that 3 weeks of resistance training cessation led to increased velocity and power of maximal unloaded limb movement in previously untrained subjects but isokinetic maximal strength reverted to pretraining levels. After a period of tapering, moderately strength trained subjects improved low velocity isokinetic strength performance of the elbow flexors for at least 8 days. Gonzalez-Bandillo et al. examined the effect of 3 resistance training volumes and reported that short-term resistance training (10 weeks) using moderate volume tended to produce greater enhancements in strength performance compared with low and high training volumes of similar intensity in trained young weightlifters.

We hypothesized short-term (4 weeks) detraining after 16 weeks of resistance training in strength trained athletes would lead to a complete loss of recently acquired maximal strength and power gains, whereas a taper phase would lead to further increases in muscle strength and power.

Forty-six physically active men were matched and randomly assigned to a TAP-tapering period (n=11), DTR- complete cessation of training (n=14), or control group (n=21), subsequent to a 16-week PRT program. Muscular and power testing and blood draws to determine basal hormonal concentrations were conducted before the initiation of training (T0), after 16 weeks of training (T1), and after 4 weeks of either DTR or TAP (T2).

No significant differences were observed between groups at the beginning of the study for 1RM measurements (exercises measured were bench press and parallel squat). Significant increases were observed in 1RM bench press for TAP and DTR groups at T1 compared with T0. After the tapering period, 1RM bench press significantly increased (2%) at T1 to T2, whereas a significant decrease (-9%) was observed in the DTR group. No significant differences in 1RM bench press were observed in the control group during the study.

No significant differences were observed between groups in muscle power output at 60% of 1 RM squat and 1RM bench press at the beginning of the study. Significant increases took place in muscle power output at 60% of 1RM bench press for TAP (29%) and DTR (26%) at T1 compared with T0. After the tapering period muscle power output in the bench press remained unaltered (1%) in the TAP group, whereas a significant decrease in muscle power output (-17%) was observed in DTR. After detraining, the magnitude of muscle power output decrement at 60% of 1RM bench press was greater than that recorded in TAP.