Masters endurance athletes tend to recover more slowly from muscle-damaging sessions and feel less recovered after hard intervals, but cutting intensity drives much of the age-related decline
Interpretation
Small comparative studies: 9 masters vs 8 young cyclists had similar physical but slower perceived recovery from hard intervals (Borges 2018); 5 masters vs 6 younger triathletes had lower muscle protein synthesis and a non-significant trend to slower time-trial recovery after downhill running (Doering 2016); 13 masters (46 y) vs 10 young recovered more slowly after a 55 km trail race (Easthope 2010). Tanaka and Seals' review links much of the age-related decline to reduced training intensity and volume. Samples are tiny, sex is often unreported, and no study tests whole training weeks.
Practical implication
Keep some high-intensity work each week but space hard sessions further apart, keep easy days easy, and give long or eccentric-heavy sessions (long and hilly runs, races) the most recovery. Inference from small studies, not a tested weekly structure.
Sources
5 sources, independently verified.
Endurance performance is maintained to about 35, declines modestly to 50-60 and more steeply after; determinants are VO2max, lactate threshold and economy (economy largely unchanged with age in trained athletes); declines in training intensity and volume appear to mediate much of the fall in performance.
Reviews endurance decline rates ranging from roughly 8% per decade (male 100km ultra) to around 15% per decade (female Ironman); notes cycling declines less steeply with age than running or swimming, and that the Hawaii Ironman's male 60-64 age group improved 20% between 1986 and 2010. VO2max is identified as the main driver, declining alongside a roughly 0.7 bpm/year fall in max heart rate.
After 6 x 30 s at 175% of peak power, recovery of strength, 10-s sprint, 30-min time trial and CK over 48 h did not differ by age. Masters reported slower perceived recovery: perceived fatigue differed (P = 0.01), with moderate effects at 48 h for lower motivation (ES 0.69), greater fatigue (0.75) and soreness (0.61).
Over 3 days of a downhill run plus three 20 km cycling time trials, myofibrillar protein synthesis was lower in masters (1.49 vs 1.70 %/day, P = 0.009). Time-trial performance 10 h after the run fell 3.0% in masters vs 1.4% in younger triathletes, a non-significant trend. Very small sample.
After a 55 km trail race, maximal voluntary contraction fell 32% in young and 40% in masters, locomotion efficiency 4.6% vs 6.3%; fatigue and damage were similar but recovery over 72 h was slower in masters. Masters averaged 46, not 50-plus.