Life will sometimes have other plans. Injuries, work, family obligations, or simply burnout may cause you to quit exercising. So what really happens when you skip a month of exercise? Your body starts detraining, where the physiological adaptations you’ve been working so hard to achieve begin to reverse. Although recovery for a week is insufficient to induce significant effects, recovery for a month is associated with quantifiable loss of cardiovascular function, muscle strength, and metabolic proficiency. They remind you to be cautious with breaks in training and return-to-play interventions.
Your Heart Becomes Out of Shape Very Rapidly with Break Effects of Exercise
Cardiovascular fitness suffers most when you do not exercise at all. Within 10-14 days of not exercising, your VO2 max (the “gold standard” for aerobic fitness) begins to decline at a rate of 6-20% per month, depending on your initial fitness level.
Significant cardiovascular changes are:
- Decreased stroke volume (amount of blood pumped per beat)
- Decreased blood plasma volume as high as 12%
- Reduced capillary density in working muscles
Elite athletes lose the most since they have the most to lose. Competitive swimmers experienced a 25% drop in VO2 max after only four weeks of total inactivity, a study found. Recreational participants in fitness programs do lose increasingly larger amounts.
Dr. Coyle’s University of Texas study found that individuals who have already trained have a cardiovascular edge several months after stopping training, due to structural heart adjustments that are not as rapidly reversible as functional adjustments.
An example is a marathon runner running 4 hours and not possibly being able to run a 5-minute pace on the road after one month of no training.
Read More: Are 10-Minute Workouts Actually Effective?
Muscle Loss and Metabolic Slowdown Hit Within Weeks
Detraining syndrome strikes both your muscles and your metabolism simultaneously. Muscle protein synthesis is reduced after 48-72 hours since your last training. This gradually diminishes your strength and size.
Strength-trained individuals lose 6-10% of their maximal strength following 2-3 weeks, while endurance-trained subjects lose power by 12-14% within four weeks. Type II (fast-twitch) muscle fibers are lost faster compared to Type I fibers, and hence, explosive power is lost before endurance capacity.
Your resting metabolic rate is also affected. For each lost pound of muscle, your body sacrifices 6-7 calories of daily caloric expenditure. With reduced NEAT (non-exercise activity thermogenesis), your metabolism has the potential to decrease by 2-5% in a month.
Hormonal responses are not exempt. Testosterone levels can decrease in men, and both men and women exhibit decreased insulin sensitivity. The release of growth hormone also decreases without the exercise stimulus.
Case study: Bodybuilder Ronnie Coleman lost 15 pounds of muscle after a forced 6-week layoff with injury, despite the diet not being altered.
Read More: Fitness Myths You Should Finally Stop Believing
Mood Changes During Exercise Disruptions and Mental Well-being
The psychological effects of stopping exercise are felt before any bodily adaptation changes occur. Exercise-induced endorphins, BDNF (brain-derived neurotrophic factor), and neurotransmitter synthesis all decrease in the absence of habitual physical activity.
Common mood changes are:
- Heightened anxiety and sensitivity to stress
- Sleep and quality variability
- Decreased cognitive function and attention
- Susceptible to symptoms of depression
Dr. John Ratey, in his book “Spark,” informs us that exercise acts as a natural antidepressant in several respects, as it enhances the levels of serotonin, dopamine, and norepinephrine. Without the neurochemical high, the majority of individuals experience what scientists term exercise withdrawal.
Sleep is disturbed when your internal body clock rhythm regulation is disrupted. Deep sleep stages can be shortened, leading to drowsiness and a slower recovery even from simple activities.
Studies show that two hours a week of exercise reduces the risk of depression by 12% in one trial involving 40,000 Norwegians. Stopping exercise reverses protective effects in weeks.
Understanding what occurs during a month of skipping training allows you to make intelligent break training choices. Detraining can’t be prevented, but the good news is that muscle memory adaptation and cardiovascular proficiency return faster than they are acquired. Typically, 50-80% of the fitness lost will be recovered within 2-4 weeks of returning.
If you must take a month off, use light exercises like walking or gentle yoga to help mitigate some of the losses. When you return, ease back in and listen to your body’s warning signs. Your fitness career isn’t over when you take a month off; it just takes a time-out.
