Rest days - they're not dirty words! In fact, programming rest days at appropriate times and at an appropriate frequency in your training cycle is almost just as important as the actual training you're undertaking.
"But surely more training is better....right?"
As with most questions we get asked as physio's and exercise professionals, there is a level of "it depends" to the answer. If you're training zero times per week well, yes, more training is definitely better, but if you're already training 4-5 times a
week, more training may potentially be of detriment to you.
It's a case of training smarter and not just harder!
So, what role do rest days play in this and why are they so important?
To put it simply, rest days allow your body to adapt to the training you have put it through and to dissipate cumulative fatigue. Let's look at this a bit closer.
Your body adapting to training
Believe it or not, during training your body actually gets weaker (yes, weaker). This is due to a number of factors including but not limited to fatigue build up, muscle micro damage and depletion of energy stores (particularly muscle glycogen).
Depending on your training age (how long you've been training consistently for), your body will take around 48 hours to completely recover/adapt from a training bout. Those who are extremely well trained, e.g. Iron men/women, will take significantly less time, where as average Joe Blogs like myself and most amateur athletes will take 36-48 hours to recover/adapt fully to the training we put our bodies through.
What this means is that if we try to train every single day, without taking rest days, our body will be in a constant state of being weakened and not have a chance to adapt and make positive gains from training. This can lead to a flat lining of improvement or overtraining which in many cases, especially in the clients I see, shows it's self as an injury.
When we train our body produces a number of substances, two of the main ones are a hormone called Cortisol (often known as "the stress hormone") and acidic hydrogen (H+) ions - more commonly known as "lactic acid".
Cortisol is an important part of being human, it is a key early piece of the recovery cycle our body goes though following training (cortisol also gets released during emotionally stressful times, not just physical). But, constant high levels of cortisol is detrimental to us, it actually becomes catabolic - meaning it works to break down muscle tissue rather than build it up...eek.
Therefore, rest days during our training programs are important to allow our body to return our cortisol levels back to normal before we train again! If this doesn't occur the constant high levels of cortisol will make us weaker.
As a side note, sustained periods of emotional stress can cause high cortisol levels, so if you're emotionally stressed and training too often then that's a double whammy for cortisol!!
And as for those pesky H+ ions....well, they're a bi-product of energy production inside our body. Basically, when our body works with an internal acid environment it is less efficient, in that the nerves don't send signals as quick, meaning your muscles don't contact as hard, meaning......you're weaker!
This is all explained a little more simply by Selye's General Adaptation Syndrome
Selye's General Adaptation Syndrome
This graph shows the various phases of the Adaptation Syndrome
The black line shows your level of strength/fitness though the phases
Phase 1 - Baseline
(a) This is where you're at prior to training
Phase 2 - Compensation
(b) this is a training session - see how the level of strength/fitness actually drops.
(c) this is your body showing positive adaption to training - training again at this stage many times over means your over all level of fitness with flat line
If you were to train prior to (c) many times, the cumulative effect would be an over all weakening/drop of fitness which leads to overtraining and injury
This graph shows how training prior to recovery/compensation over and over leads to an overall loss of strength/fitness.
Phase 3 - Resistance
(d) If an appropriate amount of time/rest is taken between training then our body will "super compensate", this normally occurs somewhere around 48 hours after training.
Allowing the body to reach this super compensation time and time again sees an overall effect of fitness/strength improvement!
So the take home messages from this are;
- Your body takes around 48 hours to recover from training
- Training prior to fully recovering too often can have detrimental effects on overall fitness
- Having rest days allows your body to super-compensate from training.
Training on consecutive days
At this stage you're probably asking "does this mean I shouldn't be training 2 days in a row?", which is a fair question
considering the info I've just presented. But no, it's absolutely fine to training 2 days, or even 3 days, in a row, just as long
as you're varying the amount you train and not training to your max every day!
I most often program a pattern of hard day, moderate/light day, rest day or moderate/light day, Hard day, rest day (see example graph)
Programming in a pattern like this means that your fitness levels wont drop so much in the short term that it can't be super compensated for on your rest day.
How many rest days should you be taking?
As a rough guide I generally recommend the following
Beginner athlete - 3 rest days per week
Experienced Amateur athlete - 2 rest days per week
Hopefully this post sheds some light on why rest days are super important to your training! If you have any further questions about this please feel free to get in contact with me. My next blog will outline what rest and recovery strategies you can be using on your rest days and post exercise to maximise your body's recovery powers.
Happy training 🏃🏿♀️🙏
Gabbett, 2015 - The training—injury prevention paradox: should athletes be training smarter and harder?
Selye, 1946 - The general adaptation syndrome and the diseases of adaptation
Selye, 1950 - Stress and the general adaptation syndrome