Lactate Threshold as a Measure of Aerobic Metabolism in Resistance Exercise

Abstract

In resistance training, load intensity is usually calculated as the percentage of a maximum repetition (1RM) or maximum number of possible repetitions (% of 1RM). Some studies have proposed a lactate threshold (LT) intensity as an optimal approach for concurrent training of cardiorespiratory endurance and muscle strength, as well as an alternative in resistance training. The objective of the present study was to analyze the results obtained in research evaluating the use of LT in resistance training. A keyword and search tree strategy identified 14 relevant articles in the Dialnet, Elsevier, Medline, Pubmed, Scopus and Web of Science databases. Based on the studies analyzed, the conclusion was that the LT in resistance exercises can be determined either by mathematical methods or by visual inspection of graphical plots. Another possibility is to measure the intensity at which LT might coincide with the first ventilatory threshold (VT1). Since performing an exercise session at one's LT intensity has been shown to accelerate the cardiorespiratory response and induce neuromuscular fatigue, this intensity could be used to set the training load in a resistance training program.

Intensity Thresholds and Maximal Lactate Steady State in Small Muscle Group Exercise

“…In recent work regarding leg press [13,14,21,[23][24][25], higher intensities as a % of 1RM during the incremental tests were applied than for half-squat exercise [17][18][19][20]. Leg press reached up to maximal incremental intensities of 60% of 1RM and half-squat exercise up to 40% of 1RM [16]. However, no comparable results similar to our LTP 1 intensity could be found.…”

“…The terms LT [13][14][15][17][18][19][20][21]23,26] and anaerobic threshold (AT) [24,25] were used synonymously. Blood lactate concentrations and heart rate values during constant-load exercise were higher in half-squat than reported in leg press exercise [16].…”

“…However, the mentioned studies showed a different methodological approach, such as applied breaks between the exercise increments and added higher incremental load intensities (maximal intensity of 60% of 1RM). Furthermore, the repetitions per minute were in a range between 12 to 30 reps•min −1 , and there was no measurement of LTP 1 [13][14][15][16][17][18][19][20][21][22][23][24][25]. The higher incremental load intensities require resting intervals in between the sets, which indicates a typical resistance type exercise definition.…”

“…Some recent articles investigated the phenomenon for incremental and continuous resistance exercise and their physiological patterns [13][14][15][16][17][18][19][20][21][22][23][24][25][26]. These studies focused on resistance exercise of lower limbs, like leg press or half-squat exercise.…”

“…Several authors have evaluated the responses that occur after a resistance training session at lactate threshold (LT) intensity [14,[17][18][19][20]25]. LT occurred at exercise intensities ranging from 27% to 36% of 1RM [16], a value that can be attributed to physiological and hemodynamic mechanisms [14]. Heart rate, lactate progression, and ventilatory parameters (VO 2 , VCO 2 , VE) stabilized during constant-load exercises at LT intensity, equivalent to lactate turn point 2 (LTP 2 ) intensity, although there was no consistent definition of threshold intensities applied.…”