Table 3.
Summary of intervention studies on PA and TL.
| Author, Reference | Year | Participants | TL Measurements | Tissue for TL Analysis | Intervention | Results |
| Borghini et al. [94] | 2015 | 17 male endurance athletes and 32 controls | PCR | Saliva | Ultra-endurance race in athletes (330 km in a maximum time of 150 h) | Endurance athletes present longer TL than controls. Acute extreme intervention increased TL attrition compared to baseline |
| Brandao et al. [95] | 2020 | 20 obese sedentary women (20–40 y) | PCR | Blood | Combined aerobic and strength training (55 min/d, 3 times/w, 8 w) | Combination training for 8 w promoted an increase in TL, fat-free mass, and physical performance |
| Chilton et al. [96] | 2014 | 22 healthy young men, nonsmokers | GE | Blood | 30 min of continuous running on a treadmill at 80% O2 | Increased expression of the key telomeric gene TERT mRNA, associated with longer TL |
| Diman et al. [97] | 2016 | 10 healthy and moderately active young men | FISH GE |
Muscle | Two cycling exercise groups: low intensity (50% VO2) and a high intensity (75% VO2). | Endurance cycling exercise increased the TERRA gene expression, a key player in telomere integrity, associated with longer TL |
| Dimauro et al. [98] | 2017 | 24 men, 12 T2D and 12 controls. | FISH | Blood | Two groups: untrained and trained (moderate PA over at least 1 y) | Individuals who participated in the regular exercise program showed longer TL |
| Friedenreich et al. [99] | 2018 | 212 Healthy women aged (50–74 y). | PCR | Blood | Two groups: aerobic exercise (45 min, 5 d/w for y, n = 99) vs. inactivity | No association between aerobic exercise and TL |
| Laye et al. [100] | 2012 | 8 participants in the “2010 Bornholm Ultramarathon 7” | PCR GE |
Muscle and whole blood | Carrying out 7 marathons on 7 consecutive d | A positive regulation of gene expression of the components of the shelterin complex was found without observing changes in TL |
| Mason C et [101] | 2013 | 439 women with overweight or obesity (50–75 y) | PCR | Blood | Four groups: weight loss with diet (n = 118), PA (n = 117), diet + exercise (n = 117) and control (n = 87); for 12 m | After 12 m, no changes were seen in the TL of the intervention groups compared to the control group |
| Puterman et al. [102] | 2018 | 68 careers of elderly people | PCR | Blood | Two groups: aerobic training and control for 24 w | Significant changes in TL were observed in aerobic exercise intervention group |
| Sjögren et al. [103] | 2014 | 49 participants (68 y) with low PA | PCR | Blood | Two groups: PA and minimal PA. Intervention for 6 m | The decrease in seated time in the intervention group was associated with TL |
| Werner et al. [44] | 2019 | 125 inactive participants | PCR FlowFISH FACS |
Blood | Three groups: aerobic endurance training; high intensity exercises; resistance training | Endurance training and high intensity, but not strength training, was associated with increased telomerase activity and TL |
| Zietzer et al. [104] | 2017 | 26 youth and 14 elderly participants | PCR | Blood | Randomization to 2 trials: -ISRT-1: crossover trial (2 separate sessions). -ISRT-2: 1 session of ISRT, and subsequently 5 d/w of 90 min. |
Telomerase activity in young individuals increased with exercise. In contrast, short-term ISRT exercises were not associated with telomerase activity. However, after 5 w of daily ISRT, telomerase increased |
TL: telomere length; bp: base pairs; PA: physical activity; y: years old; TV: television; h: hour; d: day; w: week; m: month; y: year; VO2max: maximal oxygen uptake; T2D: type 2 diabetes; ISRT: Individual Shear Rate Therapy; PCR: polymerase chain reaction; SB: Southern blot analysis of terminal restriction fragment lengths (TRF); GE: gene expression; TERT: telomerase reverse transcriptase gene; mRNA: micro-ribonucleic acid (RNA fragment); WB: Western blotting; TERRA: telomeric repeat-containing RNA gene;; FISH: fluorescence in situ hybridization.