|TITLE:||INFLUENCE OF REPETITION AND SET DISTRIBUTION ON SESSION RATING OF PERCEIVED EXERTION DURING RESISTANCE TRAINING.|
|PRINCIPLE INVESTIGATOR:||JUSTIN, KRAFT|
|OTHER INVESTIGATORS:||STEVEN ENGLAND (STUDENT)|
File Created: March 7, 2012|
Department Chair Action Date: March 8, 2012
Current Status: Final Status Report Received
|Confidentiality||Data are not linked to individuals|
STATEMENT OF PURPOSEIntroduction Rating of perceived exertion (RPE) has been shown to be a reliable method for estimating acute work load and generally corresponds well with physiological markers of training intensity such as heart rate (HR) and lactate production (Suminski et al., 1997). Estimating workload during high intensity exercise such as weight training presents a unique challenge as traditional markers such as heart rate (HR) increase disproportionately to intensity (Sweet et al., 2004). However, these activities comprise a significant portion of training load for many athletes and fitness enthusiasts. As such, new modes of estimating work load warrant investigation in order to maximize training effectiveness and reduce the likelihood of overtraining (Foster, 1998). The session RPE is a variation of the traditional RPE method intended to provide an overall estimate of training load (Foster et al., 2001) and has also been demonstrated to correspond with the traditional physiological markers of HR and blood lactate (Foster et al., 1995). Moreover, the session RPE has been demonstrated to be sensitive to changes in intensity level (as measured by % of one repetition maximum (1RM)) (Day et al., 2004; Singh, et al., 2007; Suminski et al., 1997; Sweet et al., 2004) and total work during resistance exercise training to failure (Pritchett et al., 2009). As a measure of global work load, session RPE constitutes the integration of multiple perceptual and physiological cues (for example: metabolic acidosis, variation in muscle volume recruited, muscle load, etc.) which may be mitigated by specific exercise parameters such as exercise volume (total work), repetition and set distribution, average HR, and work rate. For instance, changes in rest period may alter physiological factors such as preventing the accumulation of hydrogen ions thus altering the perceptual response (Sweet et al., 2004). Previous research from our laboratory (Kraft et al., manuscript in preparation) has found that session RPE was sensitive to changes in work rate, but did not differ based on changes in number of sets, repetitions per set, and length of rest period at matched work rates with a constant resistance. However, a trend appeared (p = 0.13) indicating that performing fewer sets but higher repetitions may result in differences in session RPE even at matched work rates. Therefore, the purpose of this study is to examine the influence of varying the distribution of repetitions per set and number of sets performed as well as varied resistances on session RPE while matching overall work rate and total work performed between independent exercise bouts. Research Question: (1) Is session RPE during resistance training a stable marker of global workload (i.e. simply a function of total work per unit time) or is it sensitive to changes in exercise parameters such as recovery period, repetitions per set, number of sets performed, and resistance? References 1. Baechle, TR, and Earle, RW. (2008). Essentials of Strength Training and Conditioning. Human Kinetics. 392-404. 2. Day, ML, McGuigan, MR, Brice, G, and Foster, C. (2004). Monitoring exercise intensity during resistance training using the session RPE scale. Journal of Strength and Conditioning Research. 18(2): 353-358. 3. Foster C (1998) Monitoring training in athletes with reference to overtraining syndrome. Med Sci Sports Exerc 30: 1164-1168 4. Foster, C, Florhaug, JA, Franklin, J, Gottschall, L, Hrovatin, LA, Parker, S, Doleshal, P, and Dodge, C. (2001). A new approach to monitoring exercise training. Journal of Strength and Conditioning Research. 15(1): 109-115 5. Foster, C, Hector, L, Welsh, R, Schrager, M, Green, MA, and Snyder, AC. (1995). Effects of specific versus cross training on running performance. European Journal of Applied Physiology. 70: 367-372. 6. Kraft, J.A., Green, J.M., Thompson, K.R., The influence of work rate on session RPE during resistance training. Manuscript in Preparation. 7. Lomax RG (2001) An introduction to statistical concepts for education and behavioral sciences. Mahwah, NJ: Lawrence Erlbaum Associates, pp. 312-314 8. Pritchett, RC, Green, JM, Wickwire, PJ, Pritchett, KL, Kovacs, MS. (2009) Acute and session RPE responses during resistance training: Bouts to failure at 60% and 90% of 1RM. South African Journal of Sports Medicine. 21(1): 23-26. 9. Robertson RJ (2004) Perceived exertion for practitioners: Rating effort with the omni picture scale. Human Kinetics Champaign, IL 10. Thomas S, Reading J, Shephard RJ. Revision of the Physical Activity Readiness Questionnaire (PAR-Q). Can J Sport Sci 17: 338-345, 1992. 11. Singh, F, Foster, C, Tod, D, and McGuigan MR. (2007). Monitoring different types of resistance training using session rating of perceived exertion. International Journal of sports physiology and performance. 2:34-45. 12. Suminski, RR, Robertson, RJ, Arslanian, S, Kang, J, Utter, AC, DaSilva, SG, Goss, FL, Metz, KF. (1997). Perception of effort during resistance exercise. Journal of Strength and Conditioning Research. 11(4): 261-265. 13. Sweet, TW, Foster, C, McGuigan, MR, Brice, G. (2004). Quantification of resistance training using the session rating of perceived exertion method. Journal of Strength and Conditioning Research. 18(4): 796-802. 14. Thomas S, Reading J, Shephard RJ. Revision of the Physical Activity Readiness Questionnaire (PAR-Q). Can J Sport Sci 17: 338-345, 1992.
STATEMENT OF RESEARCH METHODOLOGYStatement of Research Methodology Approximately 12 to 20 recreationally strength-trained (strength training ¡İ 2 times per week for a minimum of 6 weeks) males will be recruited and complete an informed consent. This number of participants is consistent with sample sizes utilized in related published research. All participants will be screened prior to the study for physical problems contraindicating physical activity (Physical Activity Readiness Questionnaire; PAR-Q; Reading et al., 1992), and procedures will be approved a priori by a university Institutional Review Board for the protection of human subjects. All subjects will be non-smokers. Volunteers will be instructed to continue with their normal diet (including dietary vitamins/supplements) through the duration of the study to decrease likelihood of confounding potential of nutritional changes during participation. Participants will be instructed to report for testing in a well hydrated state, 1.5 to 3 hours after their last meal, to refrain from resistance exercise on the day prior (~24-48 h) and all strenuous physical activity ~24 h prior to testing, and to avoid caffeine on the day of testing. Study Design Participants will complete an orientation session including determination of one repetition maximum strength (1RM) followed by two resistance training sessions consisting of six exercises (bench press, lat pull down, overhead press, upright row, triceps press down, and barbell curl) according to the following protocols: a) 3 sets x 6 reps x 1.5 min rest at 80% of 1RM b) 2 sets x 12 reps x 3 min rest at 60% of 1RM. Exercises will be performed in the order listed and trials will be counter-balanced. One warm-up set of 12 reps with 40% of the pre-determined 1RM will be performed prior to the bench press. This will be followed by a 2 minute rest period. No warm-up will be performed prior to other exercises. A standard 2 minute rest period will be provided between all exercises. These two protocols have been designed to equate workloads (offset the decrease in repetitions 3 set x 6 reps = 18 reps vs. 2 set x 12 reps = 24 reps with an equivalent increase intensity (80% vs. 60% 1RM). Heart rate (HR) via polar HR monitor (Port Washington, NY, Polar Inc.) and ratings of perceived exertion (RPE) will be measured before (pre-set) and after (post-set) each set. Session RPE (global exercise RPE) and recovery HR will be recorded 20 min after bout completion. All perceived exertion ratings will be estimated according to the 10-point omni scale for resistance training (Robertson 2004). This scale is comprised of a visual scale with verbal anchors for estimating exertion. Pre-set RPE will be a measure of perceived vigor (no actual exertion at moment recorded) and will be measured by having participants respond to the question ¡°How do you feel?¡± Session RPE will be estimated by asking participants the question, ¡°How was your workout?¡± (Foster 1998). This variable provides a subjective estimate of the global difficulty of the entire exercise bout. 1RM Determination Exercises will be performed in the order listed above. The 1RM will be defined as the heaviest weight the participant is able to lift for one complete repetition (Singh et al., 2007). Determination of the 1RM will be performed according to the procedure outlined by the National Strength and Conditioning Association (Baechle and Earle, 2008). Participants will perform a light warm-up with a resistance they estimate they can lift 5 to 10 times. Following a 1 minute rest the participant will perform a second warm-up using a weight they estimate they can lift 3 to 5 times. Two minutes rest will be provided. At this time the participant will estimate a near maximal load (one they expect to perform 2 or 3 times) and perform the final warm-up followed by 3 minutes rest. The load will be increased to an estimated maximum (add 10-20 lbs for upper body) and a 1RM will be attempted. If successful 3 minutes rest will be provided and an additional attempt will be made with a new estimated weight. If unsuccessful, 3 minutes rest will be provided and another attempt will be made with a reduced load. Loads will be adjusted based on participant feedback. The goal is to identify the 1RM within 3 to 5 attempts. A three min rest will be allowed between exercises. Statistical Analysis Repeated measures analysis of variance will be utilized to analyze difference among trials for pre-set RPE, post-set RPE, pre-set HR, post-set HR, recovery HR, and session RPE. Bonferroni follow-up tests (Lomax 2001) will be utilized to assess pairwise comparisons (set by set). Differences will be considered significant at the p ¡Ü 0.05 level (two-tailed test).
ANTICIPATED RISKS AND BENEFITSRisks and Benefits of Participation Safety of Participation There is no reasonable basis for expecting participation in this research to expose participants to serious risk or discomfort. However, exercise does pose potential risks. Potential risks to health and well being because of participation include 1) Cardiovascular injury (heart attack, stroke, and death), 2) Severe acute fatigue, 3) Lightheadedness, dizziness, nausea,4) Muscle soreness, 5) all other possible risks associated with intense exercise. Precautions are taken to reduce the risk of these occurrences. The use of screening tools (Physical Activity Readiness Questionnaire; PAR-Q; Thomas et al., 1992) as well as limiting the age of participants (only under 40 permitted to participate) would speculatively lower these risks considerably. Additionally, all participants will be regular resistance trained individuals (as defined above). We will take every precaution to ensure safety. Participants will be monitored closely throughout testing for safety. Emergency medical assistance will be sought if needed. • Participation is voluntary and participants may refuse participation at any time. • If participation is ended at any time, this will have no effect on any other care or treatment to which the participant is entitled. Benefits The primary benefit to the participant is experience in utilizing an alternative method of estimating training load. Better understanding the session RPE/training load relationship may provide exercise practitioners and coaches new information which can be utilized to devise training strategies which maximize training gains.
SUBJECT SELECTIONParticipation Selection A convenience sample of healthy college-age volunteers will be selected for this study.
CONFIDENTIALITYConfidentiality Aggregate findings (no individual data) only will be published.
PRIMARY SUPPORTING DOCUMENTClick for Word Document
Final Report on 03-11-2013Data collection is complete.
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