Medical Lasers; Engineering, Basic Research, and Clinical Application  
Changes in Total Work, Total Work Ratio, Heart Rate, and Blood Lactate during 75% 1-RM Bench Press Exercise
Ki Hong Kim1, Byung Kwan Kim2
1Department of Recreation and Leisure Sports, Dankook University, Cheonan, Korea
2Sports Science Institute, Dankook University, Cheonan, Korea
Correspondence to: Byung Kwan Kim
Sports Science Institute, Dankook University, 119 Dandae-ro, Dongnam-gu, Cheonan 31116, Korea Tel.: +82-41-550-3849
Received: May 31, 2021; Accepted: July 7, 2021; Published online: August 2, 2021.
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Background and Objectives
This study was conducted to investigate the change of total work and total work ratio for each set, peak heart rate during exercise, and blood lactate for each set during the 5-set bench press exercise at 75% one repetition maximum test (1-RM).
Materials and Methods
Seven men in their 20s with more than 6 months of experience doing resistance exercises were selected as subjects, and their 1-RM bench press was measured two weeks before the experiment and 75% 1-RM was measured one week before the experiment. In this study, total work was measured for each set, and heart rate was measured during rest and set-by-set exercise. Blood lactate was measured during rest time after each set. The raw data were analyzed by repeated one-way ANOVA.
Total work and total work ratio decreased from 1 set to 4 sets (p < .05), p < .001), heart rate increased from stable at the start of exercise (p < .001) and decreased between 3 sets and 4 sets (p < .05). Blood lactate increased continuously up to 2 sets (p < .001, p < .01).
In conclusion, total work and heart rate decreased with muscle fatigue during exercise, and blood lactate continuously increased. The results of this study are expected to be useful references for constructing resistance exercise programs in the future.
Keywords: Bench press; Total work; Heart rate; Blood lactate; Exercise set

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