When you strength train, you damage the muscle fibers you worked. This, of course, assumes you lift with enough intensity. Once muscle fibers are damaged, they need time to recover. That’s why trainers recommend not working the same muscle group again for 48 hours. The assumption is that 48 hours gives the muscles you worked enough time to recuperate. It’s during the recuperation process that the damaged muscle fibers repair and rebuild. As they say, muscles grow in strength and size not when you lift but during recovery. However, it’s really an oversimplification to say that 48 hours of recovery between workouts is enough. In some cases, 48 hours might not be enough time and you may need 72 hours or longer.
Are you giving your muscles enough recovery time between strength-training workouts? Here are five factors that impact how much recovery time you need after a strength-training workout.
Recovery Time Depends On Your Workout Intensity
It goes without saying that you need more recovery time if you do an hour-long workout and lift at 90% of your one-rep max relative to a muscle endurance workout where you train at 50% of your one-rep max. The former places significantly more stress on your muscles and breaks down more muscle tissue. If you give your muscles only 48 hours to recover, especially early in your training when your body hasn’t adapted, you run the risk of overtraining. Even if you don’t develop signs of overtraining, you’ll likely find you can’t push yourself as hard on the next workout due to fatigue. If you do a long or intense workout, the muscle groups you worked may need 72 hours or longer to recover.
Recovery Time Depends On What Muscle Groups You Are You Working?
On days when you work your arms and do mostly isolation exercises, like biceps curls and triceps kickbacks, your muscles don’t need as much recovery time as when you work large muscle groups with exercises like deadlifts and squats. When you’re working these muscles at a high percentage of your one-rep max, you’re targeting mainly fast-twitch muscle fibers. Fast-twitch muscle fibers are designed for short-term, strength and power generation and need more time to recover than endurance-oriented slow-twitch fibers. So, when you’re doing lots of compound exercises that target fast-twitch muscle fibers, 72 hours of recovery may be better.
Recovery Time Depends On Your Age
Age is a factor too. A 25-year old body recovers more quickly than a 50-year-old one. Of course, age is only a number. We all know there are “young” 50-year-old guys and gals and people who are physically “old” from a fitness standpoint before they reach 40. So, there’s no hard and fast rule on how much recovery time to give yourself based on age.
One way to monitor whether you’re overtraining is to check a first-morning heart rate before getting out of bed in the morning. If you notice a jump in your heart rate by at least 5 beats-per-minute for a few mornings in a row, it’s a warning sign that you’re training too hard and need more rest between workouts. Another option is to use a heart rate monitor and app designed to measure heart rate variability. A drop in heart rate variability can be an early sign of overtraining. Another way to monitor whether you’re recovering enough is how you feel. If it’s hard to get through a workout or it’s hard to get up the motivation to get through one, you’re not giving yourself enough recovery time.
Don’t forget that as you age, adequate sleep and good nutrition assume even greater importance. Along with adequate macronutrients (protein, carbohydrates, fats), be sure you’re getting enough micronutrients. As you age, you may need to add more magnesium and zinc to your diet. Magnesium is essential for healthy muscle and nerve function and zinc plays a key role in immune health. Also, check your vitamin D level. Vitamin D deficiency is relatively common and is linked to fatigue and muscle weakness.
Recovery Time Depends On If You Are Doing a Lot of “Eccentrics?”
An eccentric contraction is when you lengthen a muscle against resistance. An example is the lowering phase of a biceps curl or bench press. The lifting phase where you raise the weight is called the concentric portion of the movement. If you do eccentric training, where you emphasize the eccentric portion of a movement by slowing it down, you damage the muscle fibers more. Such training is referred to as “negative” training. For example, with eccentric training, you might lift the weight (concentric) in 2 seconds and lower it (eccentric) in 4 seconds, thereby prolonging the eccentric component of the exercise.
Expect to feel sorer after eccentric training. That’s because eccentric training damages muscle fibers more. To compensate, you need more time to recover before you challenge them again. According to the American College of Sports Medicine, you should give muscles trained eccentrically between 3 and 5 days to recover.
Recovery Time Depends On How’s Everything Else is Going in Your Life?
Don’t forget that factors like stress and lack of sleep place added stress on your body. In fact, chronic stress can elevate the stress hormone cortisol, a hormone that breaks down muscle tissue. If you’re skimping on sleep, give your body more time to recover between workouts, at least until you correct the sleep problem. The same goes if you’re experiencing other physical or psychological stress. More stress of any type interferes with your body’s ability to recover and repair. So, give your body more recovery time when your body is stressed due to lack of sleep or some other cause.
The Bottom Line
The 48-hour rule doesn’t necessarily apply to every situation. It’s really the minimum you should rest before working out a muscle group again. Take these five factors into account when deciding how soon to strength train a muscle group again. If you over-train, you won’t gain as much strength and you won’t do the rest of your body any favors either. Push hard, but rest enough afterward.
ACSM.org. “Eccentric Resistance Exercise for Health and Fitness”
Recovery in Training: The Essential Ingredient. Jonathan N. Mike, M.S. and Len Kravitz, Ph.D.
BreakingMuscle.com “How Much Recovery Do You Need?”
American Council on Exercise. “Training Recovery: The Most Important Component of Your Clients’ Exercise Programs”
Related Articles By Cathe:
5 Subtle and Not So Subtle Signs That You’re Training Too Hard
Can Active Rest Between Sets Help You Build More Muscle?
Do You Really Need More Exercise Recovery Time as You Age?
Related Cathe Friedrich Workout DVDs:
STS Strength 90 Day Workout Program
All of Cathe’s Strength & Toning Workout DVDs
Total Body Workouts
Lower Body Workouts
Upper Body Workouts