Effects of intra-set rest on the ability to repeat work at maximal isometric strength.
BACKGROUND
The aim of this paper was to analyze how the rest between interval repetitions in intra-set training (at maximal isometric loads) could affect the ability to repeat maximal contractions in subjects with different levels of performance and different experience in strength development work.


METHODS
Twenty subjects were divided randomly into two different groups depending on their sport characteristics: ten subjects were trained in strength development work (Group Strenght--23.1±4.6 years; 172.0±5.3 cm; 79.9±12.1 kg; 2175.6±490.8 N; 46.9±4.9 mL/kg.min), and ten subjects were trained in endurance work (Group Endurance--21.3±4.5 years; 172.4±4.1 cm; 60.0±4.6 kg; 815.5±206.5 N; 67.4±4.9 mL/kg.min). To assess the ability to repeat maximal efforts, 20 repetitions of 5 seconds were performed in a half-squat position, with 1 minute of rest between repetitions.


RESULTS
For both groups, four different phases were observed in the Interval Maximal Force test during the 20-repetition assessment: potentiation, maintenance, moderate loss, and significant loss. For the GE, the loss in maximum strength capacity began in the fourth repetition (GS4th: 3.4%, ns, Effect Size: 0.09 vs. GE3th: 1.6%; ns; ES: 0.06) and reached a statistically significant value in the twelfth repetition (GS12th: 12.7%, P=0.03, ES: 0.35 vs. GE7th: 12.5%; P=0.01; ES: 0.49). The number of repetitions at which the strength began to decrease depended on the subject's sport characteristic and performance level.


CONCLUSIONS
This study shows how an appropriate intra-set rest inclusion can significantly increase the work performed in every set without changing the muscle contraction characteristics, thus delaying muscle fatigue and maintaining the desired training objective.
Sports Training Analysis and Planning Laboratory, Department of Physical Education, University of Las Palmas de Gran Canaria, Las Palmas de Gran Canaria, Spain - pit_reseacher@yahoo.com.es.
Juan M
JM
García Manso
Teresa
T
Valverde
Luis
L
Arrones
Manuel
M
Navarro-Valdivielso
Estélio H
EH
Martin Dantas
Marzo E
ME
Da Silva-Grigoletto
D006801:Humans; D007537:Isometric Contraction / Q000502:physiology*; D008297:Male; D018763:Muscle Fatigue / Q000502:physiology; D053580:Muscle Strength / Q000502:physiology*; D011897:Random Allocation; D055070:Resistance Training / Q000379:methods*; D012146:Rest / Q000502:physiology*; D055815:Young Adult