DOES TIME-RESTRICTED EATING COST MASTERS ATHLETES STRENGTH? WHAT THE EVIDENCE SHOWS

Time-restricted eating shows up constantly in masters-athlete circles as a body-composition tool, usually with an unstated assumption riding along: that it won't cost anything on the training side. The evidence is more specific than that assumption, and the specifics matter.

The Good News: Strength and Most Performance Markers Hold Up

A 2025 systematic review and meta-analysis in Nutrients pooled 35 studies and 1,266 participants aged 18 to 65 comparing intermittent fasting or calorie restriction combined with exercise against exercise alone. The combined approach didn't significantly affect VO2 max, bench press strength, knee extensor strength, leg press strength, countermovement jump, or gait speed — and it actually increased handgrip strength slightly compared to exercise alone. It did produce the expected reductions in body weight, BMI, fat mass, and body fat percentage, alongside a small reduction in fat-free mass.

Where It Gets More Complicated: Duration and Intensity

The picture changes with longer, more demanding fasting protocols layered onto real athletic performance. A 2024 overview of systematic reviews in the British Journal of Sports Medicine examined Ramadan fasting — a month of daily sunrise-to-sunset fasting — in athletes and physically active individuals. It found consistent associations between fasting observance and decreased sleep duration, impaired sleep quality, increased fatigue, decreased vigor, and unfavorable changes in performance during high-intensity exercise testing, even though lean mass was generally preserved.

The reviewers were careful to note the underlying evidence quality was low to critically low — this isn't a clean randomized trial in masters athletes, it's an observational pattern across a specific, unusually demanding fasting protocol. But the direction is worth taking seriously: the cost of fasting shows up disproportionately in sleep and high-intensity output, not in strength or lean mass.

Time-restricted eating and month-long dawn-to-dusk religious fasting are not the same intervention wearing different names. The daily 8-to-16-hour eating window most masters athletes actually use looks much closer to the first body of evidence than the second.

The Practical Read for a Masters Athlete

An 8-hour daily eating window, timed so training happens either inside the window or right at its edge, appears compatible with maintaining strength and most performance markers while supporting body composition goals — provided total protein and calorie intake within that window is still adequate for the training load. The risk factors worth watching are the ones the Ramadan data flags specifically: sleep duration, sleep quality, and high-intensity output. If any of those three start sliding, that's the signal to widen the window rather than push through it.

The Bottom Line

Time-restricted eating combined with training doesn't appear to cost masters athletes strength or lean mass in the way many assume it might — the handgrip data actually runs the other direction. What it can cost, in longer or more aggressive protocols, is sleep quality and high-intensity capacity. Track those two, not just the scale.

This article is educational, not medical advice. Consult a qualified professional before making changes to your nutrition protocol, particularly if you have a history of disordered eating or a medical condition affected by fasting.