Am I Back at Square One After Summer Vacation?
Every time you exercise regularly—and I want to emphasize regularly—you're building up physical adaptations: strength, cardiovascular capacity, metabolic changes, body recomposition, movement skill, etc. Those are the obvious ones. They’re the reasons most of us exercise.
But you're also accumulating experience, which isn’t quite as obvious. So let’s list some of that:
- You've done something difficult when you didn't particularly feel like doing it.
- You've discovered that being uncomfortable doesn't necessarily mean that something is wrong.
- You've watched yourself get better at something you initially couldn't do.
- You've learned what exertion feels like and what recovery feels like.
- You've had workouts where you felt like a superhero—and others where you’ve felt lousy—and discovered neither one tells you very much about the next one.
- You've stopped for a while and started again.
Wait—was that last one accompanied by the sound of a record scratching?
There’s this fantasy that we're going to establish The Perfect Exercise Routine and do it uninterrupted for the next 35 years. We’ll never take a break or stop, which is utterly absurd. Bodies change. Work gets crazy. People get sick. Motivation disappears. And thankfully vacations happen, too.
In other words, life happens without checking your workout calendar first. And it turns out that when it does, your body doesn't have one fitness switch that flips from trained to untrained.
A new systematic review and meta-analysis looked at 86 randomized controlled trials involving 5,670 people to see what happened after structured exercise stopped. The researchers divided the time away from exercise into short-term (up to two months), medium-term (two to six months) and long-term (more than six months).
What I find fascinating—and encouraging—is that some adaptations proved considerably stickier than others.
Some benefits lasted surprisingly long. Body weight and waist circumference remained improved compared with where people started even in the studies that followed people for more than six months after they stopped structured exercise. So did VO₂max, a measure of cardiovascular fitness. Systolic blood pressure also remained improved in the long-term group. (The evidence for some of these longer-term findings wasn't especially strong, so don't put a six-month reminder in your calendar and hold me to it.)
Other benefits seemed to fade sooner. Improvements in body-fat percentage were clearest during the first two months after exercise stopped and became less certain after that. Improvements in fasting blood sugar, insulin, insulin resistance, triglycerides and HDL cholesterol were also still evident in that first two-month period but weren't consistently detectable in the longer ones.
And don’t count on muscle to stick around. The review didn't find lasting improvements in muscle mass or lean body mass after exercise stopped. That doesn't mean everyone immediately lost the muscle they'd built—the studies don't allow us to say that. But other detraining research has found that muscle size and strength can decline when resistance training stops, particularly in older adults. In other words, if maintaining muscle is important to you—and after 40, it should be—this is one benefit worth making an effort to preserve even when the rest of your routine falls apart.
The useful takeaway is that different adaptations appear to fade at different rates and your body doesn't simply return to factory settings because you haven't exercised lately.
Which brings me back to use it or lose it and where I think it really falls apart. While the researchers could measure what happened to people's bodies after they stopped exercising, they couldn't measure everything those people had learned.
If you've exercised consistently for six months and then life knocks you out of your routine for six weeks, you're not the woman you were six months ago. You now have a training history and know what exercise feels like. You know the difference between exertion and pain. You have some idea of what you're capable of. You know that the first workout back will probably feel harder than you think it should. And most importantly, you've done this before.
To me, this means the useful skill isn't never stopping—it's knowing how to come back.
You haven’t lost it, and you’re not starting over. You're coming back with whatever your body retained—and everything you learned along the way.
