How Fast Does Fitness Fade?

by American Council on Exercise Contributer, CERTIFIED, November 2022

There are countless reasons why your clients may need to take an extended break from their exercise routines, from illness and injury to vacation, holidays, semester breaks or a busy period at work. Even health and exercise professionals may occasionally need to take time off from their regular workouts. And we’ve all felt the effects, including sluggishness and weakness while doing exercises that used to be part of our everyday programs.

Returning to exercise after time away is often difficult, but is the loss of fitness and strength one often feels genuine and, if so, can it be quantified? Perhaps more importantly, is there a way to prevent or minimize the effects?

An ACE-supported study examined the physiological implications of hitting the “pause button” on a regular exercise training program and quantified the timing and magnitude of changes in fitness and health that occur.

Before participants completed a 13-week progressive exercise program based on the ACE Integrated Fitness Training® (ACE IFT®) Model, the researchers took the following measurements:

Anthropometric measurements (weight, height, percent body fat and waist circumference)
Fasting blood lipid and blood glucose measurements [total cholesterol, high-density lipoprotein (HDL), low-density lipoprotein (LDL), triglycerides and blood glucose]
Resting heart rate and blood pressure
Flexibility assessment (sit-and-reach test)
Muscular fitness assessments [five-repetition maximum (5-RM) testing for the bench press and leg press]
Maximal exercise testing for cardiorespiratory fitness (maximal oxygen uptake, or VO2max)
Determination of first and second ventilatory thresholds (VT1 and VT2)
Those same data were gathered after they completed the initial program. As you might expect, participants were generally fitter and healthier after training for 13 weeks. Specifically, they saw improvements in VO2max, body-fat percentage, bench press 5-RM, leg press 5-RM, sit-and-reach scores, systolic blood pressure, HDL cholesterol and triglycerides.

At this point, the participants were randomly placed into two groups. The “training” group continued the exercise program for four additional weeks, while the “detraining” group stopped the program and did not perform any structured exercise for four weeks.

Not surprisingly, those in the “training” group continued to see improvements as they maintained the program. Meanwhile, those in the “detraining” group saw a significant worsening of all measures of physical fitness, along with increases in systolic blood pressure, HDL cholesterol and triglycerides. Stated simply, stopping regular exercise erased all their hard-earned progress within one month.

Though it might seem discouraging at first glance, this research highlights the need for true lifestyle change and sustained exercise training. Something is always better than nothing when it comes to physical activity, so it’s important to ensure your clients have a plan for staying active when they won’t be training with you or doing their regular workouts.

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