Can Training Harder Prevent Injury?

Yes! And No. There is evidence that overtraining AND undertraining may increase injury risk. So, how do we find the sweet spot of training load to prevent injury? Gabbett proposed the Acute:Chronic Workload Ratio in 2016, to help us train both harder and smarter. Since then, exercise scientists have applied this model to elite youth athletes confirming the recommendation. These recommendations are only for injury prevention, not for injury rehabilitation. So, let's take a minute to talk about injury prevention for those who have graduated from physical therapy and hope to stay injury free!

For a long time, recommending an increase in load of 10% every week has been the gold standard. But this does not account for internal variables like stress, sleep, or external variables like velocity or surface changes (i.e. sand vs concrete). The Acute:Chronic Workload Ratio model helps make more precise decisions on exercise prescription.

This new recommendation uses your own personal assessment of exertion (Rate of Perceived Exertion or RPE). This RPE includes both internal and external factors for an overall rating. RPE is a validated tool that has been used in athletic training for decades. The new concept is to journal this RPE each week to establish your "acute load." Then taking the weekly acute loads and averaging them over 3-6 weeks to create a "chronic load value." Once that is established, weekly assessments can be made of the Acute:Chronic Workload Ratio.

Acute Load

What is it? Total load in one week.

How to Calculate: RPE x distance x # of sessions that week

RPE is rate of perceived exertion on a scale of 0-10.

* RPE 1-2: Very easy. You can converse with no effort

* RPE 3: Easy, you can converse with almost no effort

* RPE 4: Moderately easy; you can converse comfortably with little effort

* RPE 5: Moderate; conversation requires some effort

* RPE 6: Moderately hard; conversation requires quite a bit of effort

* RPE 7: Difficulty; conversation requires a lot of effort

* RPE 8: Very difficult; conversation requires maximum effort

* RPE 9-10: Peak effort; no-talking zone

Chronic Load

What is it? Average of acute loads over 3-6 weeks

How to Calculate: (Week 1 Acute Load + Week 2 Acute Load + Week 3 Acute Load)/3

Acute:Chronic Workload Ratio

What is it? The ratio of current load compared to chronic load.

How to Calculate: Acute Load/Chronic Load

What value is ideal? Lowest injury rates occur when this ratio is <1.2

Sound confusing? Increasing by 10% is generally still a good recommendation. If you would like a more precise prescription, then recording your load twice daily is important so you can monitor your Acute:Chronic Ratio. The Physical Therapists at CTS are happy to help you with this journaling process to keep you injury free!

Crystal Hazelton, PT, OCS

Bowen, L., Gross, A.S., Gimpel, M., & Li, F.X. (2017). Accumulated workloads and the acute:chronic workload ratio relate to injury risk in elite youth football players. British Journal of Sports Medicine. 51:452-459.
Gabbett, TJ. (2016). The training-injury prevention paradox: should athletes be training smarter and harder? British Journal of Sports Medicine. 50:273-280.

The Power of Sleep

Summer is here, days are long which is great, but how has your sleep changed? Have you found yourself staying up a little later? Rising earlier? As much as I love the long days of summer, I have found it challenging to allow my body to transition into bed, which has left me going to bed a little later. With the sun rising earlier, I am arising earlier. The poor sleep pattern slowly emerged, and I started to recognize the changes in how I felt. I knew sleep was important, but I wanted to know more.

Why We Sleep by Matthew Walker, PhD is a fascinating look into how sleep influences us on multiple system levels. His and others research have opened me to the power of sleep, and how changing some patterns can have large effects on our health and emotional wellbeing.

Interesting Facts about Poor Sleep (4-6 hours)

* Poor Amygdala and Frontal Cortex Regulation. Why does this matter? Well the amygdala is responsible for putting things into context and the frontal cortex helps us regulate our response to it. For example, have you ever found yourself unusually angry when driving after a night of no sleep? Yelling at a spouse about something that truly is not a big deal in the big picture of life? When we get less sleep, our amygdala has been found to be up to 60% more reactive. Emotional lability contributes to greater cortisol levels, stress, sympathetic neural up regulation. The influences of elevated cortisol levels are a larger discussion than this eblast but know that it is associated with lower serotonin levels, lower DHEA levels contributing to hormonal irregularity and hippocampal cell death (the hippocampus is our memory region), and altered thyroid function.

* Blood Sugar Regulation. Studies have looked at weight loss between two groups with the same diet and exercise pattern except one had 4-6 hours of sleep, while the other had 8 hours. Both lost weight; however, the 4-6-hour group lost less weight and lean muscle mass versus fat. Other studies have looked at blood sugar levels with 4-6 hours of sleep finding that with just a few nights of poor sleep, your blood tests can show you looking like a pre diabetic.

* Impaired Memory and Learning. Teachers are right, our kids need a good night sleep. And I think many of us recognize that with our children, but why do we think it would not apply to us as adults? Sleep will prep the brain to learn, as well as, process and store what we have learned. Dr. Walker and colleagues found that sleep helps to not only recall information but allow for associations to be made with previous information. His studies have found with greater than 16 hour day will have a large negative impact on short term memory.

Sleep is like a Bath for the Brain. Glymphatic system of the brain is one that clears the brain of free radicals and waste products, including amyloid-beta. This protein is toxic to the brain forming plaques. Dr. Walker reports during sleep, the glymphatic system will eliminate as much as 40% of total amyloid accumulation. When there is 36 hours of sleep deprivation, amyloid can increase levels by 25-30%. (

It is interesting to note that slow sleep wave has been found to start to decline in the late 20s, by 50s it about 50% decreased and 80s almost 100%. Such a decline may be for some of the changes in memory and learning, and diseases such as Alzheimer's. Imagine if we could improve our sleep hygiene how much this could have immediate and lifelong effects.

Immune Function. Poor sleep has been linked to impaired immune function and repair. When you are sick, cytokines will stimulate the hypothalamus signaling the need for sleep. In sleep, anti-inflammatory cascade assists in healing. How are we seeing this show up? Studies which restricted sleep to 4 hours for 1 night showed up to 70% reduction in natural killer cell activity. Less than 6 hours of sleep a night is associated with certain cancers such as bowel, breast, and prostate. If you get between 5-6 hours of sleep the week prior to getting the flu shot has shown to result in 50% less production of antibody response. (

From personal experience, I had my last knee surgery about 11 years ago and entered the surgery exhausted. I had been working and traveling with a very poor sleep regime, thinking I will have time to rest after surgery. Little did I know that this allowed for a perfect set up for my second Neuromyelitis Optica flare, which left me with extreme pain, chronic knee swelling and poor healing.

If you are not convinced yet of the power of sleep, listen to Dr. Walker's book. Be honest with yourself and habits. I have found that developing a good sleep hygiene has been critical in the management of my neurological disease. It has also been one of the hardest to incorporate, as I want to stay up, get a little "me time" after putting kids down, but I have learned that I am a better and healthier person who can show up for myself, family and patients with a good night sleep.

Sleep Hygiene Tips

As discussed, sleep is a powerful healer for our minds, body and soul. Establishing a sleep hygiene takes time and patience. It is not as simple as just going to bed, rather is it setting the environment to allow the body to go to bed and sleep. Here are some helpful tips to help you find what works for you:

Bright Light = Up All Night. The blue wave light wave in computer and TV screens can wake the brain up! Yes, it is tempting to watch TV or scroll through our phones, but it will wake you up more. Give yourself a time to shut down all devices as least 30 minutes prior to sleep. Use gamma glasses to block the blue light.

Get Outside in the Day. Allow your pineal gland to see the blue wave of morning light to wake the brain up, ideally 30-40 minutes without sunglasses. Furthermore, 6 hours of light shows to decrease cortisol levels, which in turn will allow the body to relax when it comes to bedtime. At night, turn your light to a lower hue. Ideally shut lights off 1 hour prior to bed.

Temperature. Coolness helps you sleep better. Studies indicate between 65-67 degrees is the ideal temperature. Ironically taking a warm shower can have the result of cooling the body.

Bedroom environment. If you work or watch TV in the bedroom, then your brain may no longer associate it with sleep. Ask yourself, can I participate in these activities elsewhere? Ideally the bedroom is used for sleep and intimacy.

Supplements. Melatonin is a hormone that helps tell the brain to start to prepare for sleep, it does not keep you asleep. This is a common misconception. It is ideal to create an environment to train the brain to secrete melatonin, however, it may be beneficial for some, especially with traveling. Essential oils such as lavender, vetiver, and sleep blends can help promote relaxation and sleep. White noise for some can also be very soothing to the nervous system.

Caffeine and Supplements. Be mindful of what vitamins, beverages and foods you may be consuming that can wake you up. For some, eating within an hour of sleep can disrupt sleep while others it may not have as large of an effect. Caffeine has been linked to poor sleep, so can you limit your amount?

Remember to be patient and start slowly. If you go to sleep at midnight or 1am, it may be unrealistic to start sleeping at 10pm. Cut back maybe by 20-30 minutes till you get to your ideal time. Sweet dreams.

Elizabeth Leeds, DPT, FAFS

Let's Talk About Sex
Thursday, July 11th at 6:30pm
at Shop Good in North Park 

Join Comprehensive Therapy Services' own Dr. Rose Schlaff, PT, DPT, WHC, IF for open and non-judgmental conversation about sex! 

Shop Good is located at 3030 North Park Way, San Diego, CA 92104. Visit for more information and to RSVP.

Men's Pelvic Pain Support Group
Tuesday, July 16 at 6pm

1 in 12 men suffer from pelvic pain and most suffer in silence.

Let's gather together and share our experience and resources. Together we can heal & help others get on the road to recovery. For more information, contact Milan at or 858-457-8419.