Exercise training is an adaptive process. The body first adapts to the stress of exercise with increased fitness if the stress is above moderate intensity. To achieve maximum effectiveness, adaptations of muscle to stress and deconditioning. Training should include overload, specificity, reversibility, and individual differences.
Overall, skeletal muscle is very adaptability. If a muscle is stressed it adapts and improves its function. When we lift weights our muscles increase in size (hypertrophy) and improve their strength. Larger muscles allow lifting heavier loads. If a muscle receives less stress than it’s used to, it shrinks (atrophies). The purpose of physical training is to stress the body so it improves its ability to exercise. Physical training is valuable only as long as it forces the body to adapt to the stress of physical efforts. If there is not enough stress to overload the body, then no adaptation occurs. Improvements in performance occur when the appropriate exercise stresses are used in the athlete’s training program.
Campos (2002) used thirty-two untrained men [mean age 22.5 years, height 178.3 cm, body mass 77.8 kg]participated in an 8-week progressive resistance-training program. Subjects were divided into four groups:
1. Low repetition group (Low Rep, n = 9) performing 3-5 repetitions maximum (RM) for four sets of each exercise with 3 min rest between sets and exercises, an intermediate repetition group (Int Rep, n = 11) performing 9-11 RM for three sets with 2 min rest.
2. High repetition group (High Rep, n = 7) performing 20-28 RM for two sets with 1 min rest.
3. A non-exercising control group (Con, n = 5). Three exercises (leg press, squat, and knee extension) were performed 2 days/week for the first 4 weeks and 3 days/week for the final 4 weeks. Maximal strength [one repetition maximum, 1RM), local muscular endurance (maximal number of repetitions performed with 60% of 1RM), and various cardiorespiratory parameters (e.g., maximum oxygen consumption, pulmonary ventilation, maximal aerobic power, time to exhaustion) were assessed at the beginning and end of the study.
So which Strength Training Group was best?
Maximal strength improved significantly more for the Low Rep group compared to the other training groups, and the maximal number of repetitions at 60% 1RM improved the most for the High Rep group. In addition, maximal aerobic power and time to exhaustion significantly increased at the end of the study for only the High Rep group. All three major fiber types (types I, IIA, and IIB) hypertrophied for the Low Rep and Int Rep groups, whereas no significant increases were demonstrated for either the High Rep or Con groups. However, the percentage of type IIB fibers decreased, with a concomitant increase in IIAB fibers for all three resistance-trained groups. These fiber-type conversions were supported by a significant decrease in MHCIIb accompanied by a significant increase in MHCIIa. No significant changes in fiber-type composition were found in the control samples. Although all three training regimens resulted in similar fiber-type transformations (IIB to IIA), the low to intermediate repetition resistance-training programs induced a greater hypertrophic effect compared to the high repetition regimen. The High Rep group, however, appeared better adapted for submaximal, prolonged contractions, with significant increases after training in aerobic power and time to exhaustion. Thus, low and intermediate RM training appears to induce similar muscular adaptations, at least after short-term training in previously untrained subjects. Overall, these data demonstrate that both physical performance and the associated physiological adaptations are linked to the intensity and number of repetitions performed, and thus lend support to the “strength-endurance continuum”.
COR provides athletes and everyday people who want to build muscle with safe weight training that stresses the body. When training using weights it is important to have perfect form that will not hurt that individual. If you are trying to stress the body by using too heavy of a weight, this can lead to serious injuries. On top of this, COR uses muscle physiology for prescribing sets, repetitions, and exercises, maximizing efficiency and safety.
1. Campos GE, Luecke TJ, Wendeln HK, Toma K, Hagerman FC, Murray TF, Ragg KE, Ratamess NA, Kraemer WJ, Staron RS. Muscular adaptations in response to three different resistance-training regimens: specificity of repetition maximum training zones. Eur J Appl Physiol. 2002 Nov;88(1-2):50-60. Epub 2002 Aug 15.
Written by Chris Barber, CPT