Enhanced Protein Translation Underlies Improved Metabolic and Physical Adaptations to Different Exercise Training Modes in Young and Old Humans

High-intensity interval training (HIIT) produces the most significant improvements in aerobic capacity.

“The greatest improvements in aerobic capacity are elicited by moderate-to-vigorous-intensity aerobic exercise (MICT), with the most significant effects observed with high-intensity interval training (HIIT, 85–95% peak heart rate for 1–4 min intervals [119,120]).”

PRT increases mitochondrial protein fractional synthesis rates and improves mitochondrial function.

“strong evidence shows that PRT increases mitochondrial protein fractional synthesis rates [119,371] and improves mitochondrial function [119,372].”

The greatest improvements in aerobic capacity are elicited by moderate-to-vigorous-intensity aerobic exercise (MICT), with the most significant effects observed with high-intensity interval training (HIIT, 85-95% peak heart rate for 1-4 min intervals).

“The greatest improvements in aerobic capacity are elicited by moderate-to-vigorous-intensity aerobic exercise (MICT), with the most significant effects observed with high-intensity interval training (HIIT, 85–95% peak heart rate for 1–4 min intervals [119,120]).”

Strong evidence shows that PRT increases mitochondrial protein fractional synthesis rates and improves mitochondrial function.

“More recently, strong evidence shows that PRT increases mitochondrial protein fractional synthesis rates [119,371] and improves mitochondrial function [119,372].”

High-intensity interval training, rather than moderate aerobic exercise, has the greatest impact on increasing mitochondrial oxidative capacity and mitochondrial protein synthesis and content while concurrently improving insulin sensitivity in older adults.

“Recent findings indicate that highintensity interval training, rather than moderate aerobic exercise, has the greatest impact toward increasing mitochondrial oxidative capacity and mitochondrial protein synthesis and content while concurrently improving insulin sensitivity in older adults (141).”

Insulin sensitivity can be improved irrespective of age by either aerobic or resistance exercise.

“Furthermore, insulin sensitivity can be improved, irrespective of age, by either AE or resistance exercise (RE).111”

Despite improvements in mitochondria in older trained individuals, exercise cannot completely maintain VO2max at levels observed in young subjects.

“However, despite the improvements in mitochondria in older trained individuals, the beneficial effect of exercise cannot completely maintain VO2max at levels observed in young subjects.111”

Much of the decline in mitochondria, especially mitochondrial content and respiration, can be reversed by 3 months of high-intensity interval training.

“In fact, much of the decline in mitochondria, especially mitochondrial content and respiration, can be reversed by 3 months of high-intensity interval training (HIIT).111”

HIIT is much less effective than resistance exercise training for improving muscle strength.

“Although HIIT modestly increases muscle mass, it is not nearly as effective at improving muscle strength as RET.111”

The stress imposed by exercise training is recognized as the most effective stimulus for mitochondrial biogenesis as part of redox-sensitive adaptation, resulting in enhanced mitochondrial function across the life course.

“Indeed, the stress imposed by exercise training is recognized as the most effective stimulus for mitochondrial biogenesis as part of redox-sensitive adaptation [96,97,98], resulting in enhanced mitochondrial function across the life course [99,100].”