Aerobic Adaptations to Resistance Training: The Role of Time under Tension

Abstract

Generally, skeletal muscle adaptations to exercise are perceived through a dichotomous lens where the metabolic stress imposed by aerobic training leads to increased mitochondrial adaptations while the mechanical tension from resistance training leads to myofibrillar adaptations. However, there is emerging evidence for cross over between modalities where aerobic training stimulates traditional adaptations to resistance training (e.g., hypertrophy) and resistance training stimulates traditional adaptations to aerobic training (e.g., mitochondrial biogenesis). The latter is the focus of the current review in which we propose high-volume resistance training (i.e., high time under tension) leads to aerobic adaptations such as angiogenesis, mitochondrial biogenesis, and increased oxidative capacity. As time under tension increases, skeletal muscle energy turnover, metabolic stress, and ischemia also increase, which act as signals to activate the peroxisome proliferator-activated receptor gamma coactivator 1-alpha, which is the master regulator of mitochondrial biogenesis. For practical application, the acute stress and chronic adaptations to three specific forms of high-time under tension are also discussed: Slow-tempo, low-intensity resistance training, and drop-set resistance training. These modalities of high-time under tension lead to hallmark adaptations to resistance training such as muscle endurance, hypertrophy, and strength, but little is known about their effect on traditional aerobic training adaptations.

A Description of Exercise Programs Implemented During a Firefighter Training Academy

“…If considered as a dichotomy, AT imposes greater cardiorespiratory and metabolic stress than RT, while RT imposes greater mechanical tension and muscle damage than AT 68,69 . Thus, eventual adaptations to AT and RT are considered to be more aerobic and anaerobic, respectively 68,69 .…”

“…67 If considered as a dichotomy, AT imposes greater cardiorespiratory and metabolic stress than RT, while RT imposes greater mechanical tension and muscle damage than AT. 68,69 Thus, eventual adaptations to AT and RT are considered to be more aerobic and anaerobic, respectively. 68,69 However, because the essential tasks of firefighting require the concomitant utilization of aerobic and anaerobic energy systems, 1,3,40 hybrid programs like HICT, HIFT, and MM-HIIT have been recommended for this population.…”

“…68,69 Thus, eventual adaptations to AT and RT are considered to be more aerobic and anaerobic, respectively. 68,69 However, because the essential tasks of firefighting require the concomitant utilization of aerobic and anaerobic energy systems, 1,3,40 hybrid programs like HICT, HIFT, and MM-HIIT have been recommended for this population. [70][71][72] As shown in Table 3, the highest cardiorespiratory stress and sRPE were sustained during AT, while the lowest cardiorespiratory stress and sRPE were sustained during RT and CT.…”