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<\/p>\nVO\u2082 max can drop 7 percent in just 12 days\u2014but muscle strength holds on longer<\/p>\n
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(Photo: Ayana Underwood\/Canva)<\/p>\n
Published October 23, 2025 04:04AM<\/p>\n
Schedules change, injuries happen, and life causes unforeseen interruptions to your plans. If you\u2019re a dedicated exerciser, being thrown off your usual program can feel daunting: Will you lose all your hard-earned gains in strength, speed, or endurance if you have to take a break?<\/p>\n
Cardiovascular capacity will decline more quickly than strength or muscle mass, but some of the impact of detraining depends on the length of your break and what you do during your downtime. Your age and existing fitness level can be factors as well.<\/p>\n
After a Few Days<\/p>\n
For both cardiovascular and strength gains, taking a few days off for a long weekend, for recovery, due to minor injury or illness, or just because plans get in the way, won\u2019t have a negative impact.<\/p>\n
In fact, as physical therapist Grayson Wickham told Outside previously<\/a>, a three or\u00a0four-day rest period can actually be beneficial because it gives your body time to recover and get stronger following your last workout, especially if it was challenging.<\/p>\n After Two Weeks<\/p>\n As your time off increases, you\u2019re more likely to see an initial decline in cardiovascular capacity than in muscular strength and mass. Much of that loss will be in your VO2 max, or the amount of oxygen your body can take in while exercising. As that number decreases, exercises such as\u00a0running and cycling will feel more challenging and tiring, and your endurance may decline as well.<\/p>\n A small study<\/a> published\u00a0in 2022 found that a two-week pause in training resulted in a decrease in VO2 max among 15 male endurance athletes (though they maintained their muscular endurance).<\/p>\n A 2024 meta-analysis<\/a> found that in trained endurance athletes, VO2 max<\/a> is likely to decline by about seven percent after a 12-day break in training.<\/p>\n During a two-week break in training, you\u2019re unlikely to see any decreases<\/a> in muscle strength, though you may feel some initial stiffness or weakness when you first return to the gym.<\/p>\n After One Month<\/p>\n The 2024 meta-analysis mentioned above also found that after five weeks, VO2 max is likely to decrease by 10 percent. That decline continues as more time passes\u201413 percent at a month-and-a-half and 20 percent at around two months\u2014up to twelve weeks, after which point no additional decreases were observed.<\/p>\n During this stretch, you\u2019re still unlikely to notice any loss of muscle strength or size, though joint stiffness may continue to progress if you\u2019re not moving much.<\/p>\n Over One Month and Beyond<\/p>\n A 2024 study<\/a> found that if you\u2019ve been training regularly, you\u2019re more likely to regain your strength and size faster after a period of no exercise. In the study, male and female participants with limited strength training experience were put on a ten-week resistance training program, followed by ten weeks of no training, followed by a repeat of the initial ten-week program. Participants regained their muscle strength and size rapidly during the retraining cycle. The authors noted that, provided you have been training consistently, you don\u2019t need to be \u201ctoo concerned about occasional short-term training breaks.\u201d<\/p>\n