BEETter AGING: Short-Term Dietary Nitrate Supplementation Enhances Muscle Contractile Properties in Older But Not in Young Adults.
- 2025-03-18
- Medicine and science in sports and exercise 57(8)
- Letizia Rasica
- Marta Colosio
- Alessandra Ferri
- Giovanni Baldassarre
- Chris Easton
- Mia Burleigh
- Gianluca Vernillo
- Roberto Bottinelli
- Mauro Marzorati
- Simone Porcelli
- PubMed: 40098056
- DOI: 10.1249/mss.0000000000003708
Study Design
- Type
- Randomized Controlled Trial (RCT)
- Population
- 11 older (69 ± 4 yr, O) and 11 young (26 ± 2 yr, YG) adults
- Methods
- consumed either NO3--rich beetroot juice (BR) or placebo (PLA), for 7 d
- Blinding
- Double-blind
- Duration
- 7 d
- Funding
- Unclear
Purpose
Dietary nitrate (NO 3- ) supplementation has been shown to improve skeletal muscle contractile function and reduce fatigue, potentially due to alterations in skeletal muscle Ca 2+ handling/sensitivity. Because aging muscle can have impaired Ca 2+ handling, the aim of the study was to evaluate the effects of dietary NO 3- supplementation on muscle contractile properties in young and older adults.Methods
Eleven older (69 ± 4 yr, O) and 11 young (26 ± 2 yr, YG) adults consumed either NO 3- -rich beetroot juice (BR) or placebo (PLA), for 7 d. After supplementations, plantar flexors of dominant leg were evaluated as follow: a) maximal voluntary isometric contraction (MVIC), b) potentiated single twitches (Tw pot ) and double twitches electrical stimulations at the frequency of 100 Hz (Db 100 ) on the tibial posterior nerve, c) a fatigue isometric (70% of MVIC) test until exhaustion. The force-frequency relationship was assessed with trains of electrical pulses across a wide range of frequencies on the muscle belly of the nondominant leg.Results
BR supplementation increased plasma [NO 3- ] and nitrite [NO 2- ] in both O and YG compared with PLA (more than sevenfold; all P ≤ 0.02). No changes were observed in MVC, Tw pot , and Db 100 force after BR compared with PLA in both YG and O. Only in O, Db 100 area under the curve (-7 ± 6 N·s change from PLA) and half relaxation time (-0.05 ± 0.06 s change from PLA) were significantly reduced, and time to exhaustion (+32 ± 43 s change from PLA) was significantly longer (all P < 0.02) after BR. In O, BR also significantly increased submaximal force produced by trains of electrical pulses ( P < 0.001).Conclusions
NO 3- supplementation positively affects muscle contractile proprieties, submaximal electrically evoked force production, and fatigue resistance in older adults, whereas these positive results were not found in young.Research Insights
No changes were observed in MVC, Tw pot, and Db100 force after BR compared with PLA in both YG and O.
- Effect
- Neutral
- Effect size
- Small
BR also significantly increased submaximal force produced by trains of electrical pulses (P < 0.001).
- Effect
- Beneficial
- Effect size
- Small
No changes were observed in MVC, Tw pot, and Db100 force after BR compared with PLA in both YG and O.
- Effect
- Neutral
- Effect size
- Small
No changes were observed in MVC, Tw pot, and Db100 force after BR compared with PLA in both YG and O.
- Effect
- Neutral
- Effect size
- Small
Only in O, Db100 area under the curve (-7 ± 6 N·s change from PLA) and half relaxation time (-0.05 ± 0.06 s change from PLA) were significantly reduced, and time to exhaustion (+32 ± 43 s change from PLA) was significantly longer
- Effect
- Beneficial
- Effect size
- Small
Only in O, Db100 area under the curve (-7 ± 6 N·s change from PLA) and half relaxation time (-0.05 ± 0.06 s change from PLA) were significantly reduced, and time to exhaustion (+32 ± 43 s change from PLA) was significantly longer
- Effect
- Beneficial
- Effect size
- Small
Only in O, Db100 area under the curve (-7 ± 6 N·s change from PLA) and half relaxation time (-0.05 ± 0.06 s change from PLA) were significantly reduced, and time to exhaustion (+32 ± 43 s change from PLA) was significantly longer
- Effect
- Beneficial
- Effect size
- Small