Do Telomeres Adapt to Physiological Stress? Exploring the Effect of Exercise on Telomere Length and Telomere-Related Proteins

Table 1

(a) Studies showing a positive association of physical activity with telomere length. (b) Studies showing no association between physical activity and telomere length. (c) Studies showing an inverted U relationship between physical activity and telomere length.

(a)

Positive association of physical activity with telomere length
Author	Study design	Subjects (𝑁)	Tissue	Telomere length method
Cherkas et al. [61]	Cross-sectional	Twin cohort (2401)	Leukocytes-PBMCs	T/S qPCR
Werner et al. [63]	Cross-sectional	Young sedentary (26),; young athletes (25),; older sedentary (26), and; older athletes (25)	Leukocytes	QFISH and T/S qPCR
Mirabello et al. [60]	Cross-sectional	Prostate cancer cases (612) versus age-matched controls (1049)	Leukocytes	T/S qPCR
Simpson et al. [59]	Longitudinal	Endurance trained men (9)	Sorted populations of PBMCs	T/S qPCR
Puterman et al. [45]	Cross-sectional	Postmenopausal women (63)	Leukocytes	T/S qPCR
LaRocca et al. [62]	Cross-sectional	Young sedentary (15),; young athletes (10),; older sedentary (15), and; older athletes (17)	Leukocytes	Southern blot TRF
Krauss et al. [64]	Cross-sectional	Heart and Soul population (944)	Leukocytes	T/S qPCR
Kim et al. [58]	Cross-sectional	Postmenopausal women (44)	Leukocytes-PBMCs	T/S qPCR
Du et al. [57]	Cross-sectional	Nurse's health study (7,813)	Leukocytes	T/S qPCR
Osthus et al. [70]	Cross-sectional	Young sedentary (5),; young athletes (5),; older sedentary (5), and; older athletes (5)	Skeletal muscle	T/S qPCR

Ref: reference. T/S qPCR: the ratio of telomere PCR value to single-copy gene value derived from quantitative PCR. TRF: terminal restriction fragment analysis. QFISH: quantitative fluorescence in situ hybridization with a telomere probe. 𝑁: number of subjects.

(b)

No association of physical activity with telomere length
Author	Study design	Subjects (𝑁)	Tissue	Telomere length method
Woo et al. [69]	Cross-sectional	65 years or older Chinese men and women (4000)	Leukocytes	T/S qPCR
Ornish et al. [50]	Longitudinal	Prostate cancer patients (30)	Leukocytes	T/S qPCR
Song et al. [68]	Cross-sectional	Diverse population (103)	Leukocytes	T/S qPCR
Mason et al. [67]	Randomized trial	Postmenopausal women (439)	Leukocytes	T/S qPCR
Mathur et al. [66]	Cross-sectional	Marathon athletes (17) versus matched individuals (15)	Lymphocytes and granulocytes	T/S qPCR
Kadi et al. [71]	Cross-sectional	Resistance trained strength athletes (7) versus active individuals (7)	Skeletal muscle	Southern blot TRF
Ponsot et al. [72]	Cross-sectional	Diverse population; (42)	Skeletal muscle	Southern blot TRF
Rae et al. [73]	Cross-sectional	Healthy endurance runners (18) versus sedentary age-matched (19)	Skeletal muscle	Southern blot TRF
Laye et al. [74]	Longitudinal	Marathon athletes (8)	Skeletal muscle and leukocytes	T/S qPCR

Ref: reference. “Diverse population” refers to a sample with a broad age range with both males and females of multiple races. T/S qPCR: the ratio of telomere PCR value to single-copy gene value derived from quantitative PCR. TRF: terminal restriction fragment analysis. 𝑁: number of subjects.

(c)

Inverted U relationship of physical activity with telomere length
Author	Study design	Subjects (𝑁)	Tissue	Telomere length method
Ludlow et. al. [43]	Cross-sectional	Population, 50–70-year-olds; (69)	Leukocytes-PBMCs	T/S qPCR
Savela et al. [75]	Cross-sectional	Men (782)	Leukocytes	Southern blot TRF
Collins et al. [76]	Case-control	FAMS athletes (13) versus healthy endurance athletes (13)	Skeletal muscle	Southern blot TRF

Ref: reference. “Diverse population” refers to a sample with a broad age range with both males and females of multiple races. T/S qPCR: the ratio of telomere PCR value to single-copy gene value derived from quantitative PCR. TRF: terminal restriction fragment analysis. 𝑁: number of subjects. FAMS: fatigued athlete myopathic syndrome.