The Rate of Increase in Leg Strength Depending on the Tempo of Performing Squats
S. I. Lelikov, N.N. Saxanov
53 – 55:1976
Translated by Andrew Charniga, Jr.
The effect of the exercise tempo on the rate of improvement of strength has been explored in many works (N.V. Zimkin, 1954, 1956, 1960; G. Vasiliev, 1954, 1956; V.D. Monogarov, 1957, 1959; A. N. Vorobeyev 1964, 1965, 1967, 1970, 1971; V. M. Zatsiorsky, 1966; A. I. Falameyev, 1974, et al). However, there was no unanimity of opinion among the specialists. One suggests that a rapid exercise tempo is the most effective for increasing strength; another said the same about a moderate tempo, and still a third said a slow tempo was the most effective.
There is no experimental research in either the weightlifting literature (or for other types of sports, for that matter) dealing with a comparative analysis of whether a fast, moderate, or slow tempo of performing exercises, under the natural conditions of training, is the most effective means for increasing strength.
An earlier analysis of the results in the snatch, the clean and jerk, and back squats showed that squats performed at a moderate tempo produced the most improvement. In order to determine the reliability of the preliminary data obtained, we conducted a pedagogical experiment to reveal the effectiveness of various exercise tempos on the weightlifter’s increase in strength.
The experiment lasted four months. We utilized a complex of training devices for obtaining crucial information with biofeedback (signal lamps). Four programs enabled us to determine the assigned exercise tempos; they were fast, moderate, slow, and very slow.
The subjects trained three times per week during the experiment for 1.5 to 2 hours. Weightlifters with two years of training (classified youths 17 years old) and novices with six months training experience (7 class III, 8 youth class I, 8 youth class II and 10 novices) took part in the experiment. The 32 subjects were divided into four groups of eight (according to age, height, weight, qualification, sport results in the snatch, the clean and jerk, and squat).
The sportsmen in all of the groups did the back squat (in the yielding and overcoming regimes). The weight of the barbell for this exercise was 80%. The sportsmen did fifteen lifts per workout (5 sets of 3 repetitions per set). Every five weeks we tested the athletes. The 80% weight was adjusted depending on the subject’s new best results. All of the subjects trained under equivalent conditions throughout the experiment.
They trained according to a unified training plan where all did the same volume and intensity of loading, number of exercises, lifts, general and special warm -up, and so forth. The subjects trained 48 times over the course of the experiment. Each subject executed an average of 700 lifts with 80% weights. The sports men of the 1st group did their exercises with a fast tempo (2 sec, average speed of movement was 0.6 m/sec); the 2nd group performed their exercise with a moderate tempo (2.5 sec, average speed of movement 0.5 m/sec); the 3rd group employed a slow tempo (3 sec, an average speed of 0.4 m/sec); and, the 4th group employed a very slow (6 sec, an average speed of movement 0.2 m/sec).
The data obtained in this experiment is presented in table 1. It shows that the subjects who exercised with a moderate tempo made the most progress of 21.3±1.2 kg or 20.65% over their initial results (103.1±11 kg). The improvement of strength of this group were substantially greater than the improvement of strength over the other groups (p<0.05). There was not a statistically reliable difference between the strength increases of the other three groups who exercised with a fast, slow, and very slow tempo (p>0.05).
Table 1. Mean data (in kg) of improvement of squat results depending on the tempo of performing the exercise:
|Tempo of exercise||Initial result||Improvement||% improvement|
We also determined the energy expenditure relative to the tempo with which the exercises were performed.
The subjects performed the squat with a training device in the following sequence by beginning with a fast tempo, then moderate, slow, and finally a very slow tempo. The magnitude of energy expenditure was determined by means of the indirect calorimetry utilizing the East German gas analyzer “Spirolit.” We employed the method developed by one of the authors of this paper (N.N. Saxonov, 1969) to determine the amount of work performed.
The data obtained is presented in table 2.
|Exercise Tempo||Energy expenditure during exercise, kcal||Specific Energy expenditure, Kcal/kgm|
The data shows that there is no statistically reliable difference between performing squats fast, moderate, slow and very slow, with respect to energy expenditure. This indicates that the work performed relative to energy expenditure is practically uniform. A reliable difference was observed only between a fast and a very slow tempo, which is in harmony with Y.M. Berkovitch’s data (1964).
Our data and research enable us to recommend a moderate tempo (2.5 sec, a movement speed of 0.5 m/sec) for the 17 year old novice and class III athletes to perform squats with 80% weights. This method resulted in the greatest improvement. Furthermore, the energy expenditure of moderate exercises tempos is practically the same as the other exercise tempos.