It's The Hip Not The Knee

My patient came with anterior (or front) knee pain yesterday. She had been to see another physiotherapist who said she needed to strengthen her quadriceps muscle. Who says physios can't prescribe exercises compared to strength and conditioning coaches? 

Pardon the link - it seems that almost every single patient that comes to our clinic (after seeing another physiotherapist) had been given exercises to do during the treatment session itself. Maybe that's why the general public thinks all a physiotherapist does is teach exercises.

In our clinics, we may give an exercise or two to our patients near the end of the session, for them to do at home. However, we do not make our patients do any exercises DURING the treatment session. We treat them, mostly using our hands. We do treatment that the patients cannot do themselves, while they are in the clinic. 

Anyway back to my patient with knee pain who was asked to strengthen her quads. I've written a few times since 2009 that treating (or strengthening the hip) is much more important than strengthening the knee (quadriceps). Well, here is further proof.

In this systematic review referenced below, researchers studied data from 14 suitable studies (out of 119) that were found between 1994 and September 2019. Results from all 14 studies demonstrated that strengthening the hip 2-4 times a week (for 3-8 weeks) effectively relieved pain and improved knee function compared to quadriceps stengthening and no exercise. This lasted for up to 12 months post intervention.

The researchers recommended that hip muscle strengthening be a standard clinical practice while treating patients with anterior knee pain. So if the physiotherapist that you're seeing gets you to do quadriceps strengthening for your anterior knee pain, you need to tell them that hip strengthening is superior to quadriceps exercise. Please note that hip strengthening does not mean clam shell exercises.

Please also note that this present review included  randomized clinical trials that also got their subjects to do both hip plus quadriceps strengthening exercises over just the quadriceps alone. All except one study showed that hip and quadriceps strengthening exercises over just quadriceps alone. There were no no hip plus quadriceps strengthening versus hip exercises alone study done.

Perhaps a combination of hip-quadriceps strengthening may be a more effective strategy in the treatment of anterior knee pain? We can certainly try that in our clinic before more studies are done. It would depend on what we find to be weak at your objective examination ;)

Reference

Alammari A, Spence N, Narayan A et al (2022). Effect Of Hip Abductors And Lateral Rotators' Muscle Strengthening On Pain And Functional Outcome In Adult Patients With Patellofemoral Pain : A Systematic Review And Meta-analysis. J baxk Muscl Rehab. Pre-press. pp 1-26. DOI: 10.3233/BMR-220.

** For those of you wondering, there were no standardized protocol for hip and knee exercises in the various studies. The common hip exercise protocol included hip abduction against an elastic band while standing and with weights in a side-lying position coupled with hip lateral rotation against an elastic band while seated and hip extension (3 sets of 10 repetitions). 

Conversely, quadriceps strenthening in all studies generally involved weight bearing and non weight bearing exercises such as closed kinetic chain exercises, seated knee extension, leg press, squatting and stretching of hamstrings and quadriceps (3 sets of 10 repetitions). 

When is the Best Time To Exercise?

Good time to exercise

I was not a morning person when it comes to exercise/ training before I started work. I used to train mostly in the late afternoons. After starting work as a physiotherapist and seeing patients the whole day, it often left me too tired to train after work. It got worse when I had to help out with treating the athletes at national team trainings. These trainings often ended past 9 pm, leaving me with little time to train.

If you are a sports fan, you will know that NBA Finals, Champions League matches etc are all played in the late evenings. Almost all track and field world records are set in the evening as well. However, most road running world records, including Eliud Kipkoge's sub 2 hour marathon, are set in the morning.

It is not all physiological reasons though. Big track meets, NBA and Champion League Finals are at a venue, unlike mass participation endurance events which require early start times for road closures and avoiding hot weather. So when the human body is primed for maximal performance?

Evidence regarding circadian rhythms and physical performance suggest that we are at our best in the late afternoon or early evening. For most people, this is between 4-7 pm. 

A meta-analysis of 29 articles (63 were found but only results from 29 were suitable) were divided into four categories, jump height, anaerobic power (30 sec cycling sprint), hand grip strength and endurance exercise.  

Strong evidence showed that for jump height and anaerobic power the peak is between 1-7 pm while some evidence shows that hand grip strength peaks between 1-9 pm. 

However, most of the studies failed to find any significant difference for endurance exercise. Perhaps it may be difficult to look for subjects willing to run a series of 10 km runs (or longer) compared to hand gripping tests or jumps or bicycle testing.  Note that a higher core temperature may hinder rather than help endurance exercise.

During the late afternoons is when our core temperature is highest having risen from its lowest point when you get up in the morning. A warmer body means faster metabolic reactions, faster transmission of nerve signals and muscles that are warmed up and have more range. Definitely better for injury prevention.

If you shift your sleep-wake cycle by a few hours you can shift the timing of your peak performance by a few hours. The F1 drivers do this by remaining in their own timezone from Europe when they do the night race in Singapore.

However, there are advantages to exercising in the morning since you can typically control your mornings more than your evenings. All kinds of hurdles or excuses can pop up throughout the day that can prevent you from being consistent with your exercise. You may have to ferry your kids, get errands done or work late.  

Most endurance events like triathlons and marathons begin in the morning. If you want to train yourself to race under such conditions, training in the morning certainly helps. I used to wake up at 4.30 to attend swim training at 5.30 am by riding my bicycle there. Early morning race start times didn't bother me anymore after I got used to that.

Your circadian rhythm regulates blood pressure, body temperature, metabolism, alertness amongst other physiological functions. Tweaking your circadian rhythm can 'teach' your body to perform better at certain times. Just like when you need to adjust to a new waking time on your alarm clock, your body will get used to the change and you may even wake up before the alarm goes off after a while. 

Once you determine that a particular time of day works best for your schedule, body, event etc, you can start to train your body to match it. If you exercise in the morning, your body will learn to adjust to exercising at that time. You will get used to waking up, eating, drinking, using the toilet etc. After a while it becomes second nature.

Evidence may show that the best time of the day to exercise is the late afternoon to early evening. My take is exercise at whatever time suits you best as some exercise is better than no exercise, especially in Singapore when the weather is warm year round. Researchers in Guadeloupe failed to show any difference in the time of day for sprint cycling, squat and jump performance because it was always warm and humid there. And Guadeloupe's weather is just like Singapore.

References

Aoyama S and Shibata S (2020). Time of Day Dependent Physiological Responses To Meal And Exercise. Frontiers Nutr. DOI: 10.3389/fnut.2020.00018

Blonc S, Perrot S, Racinais S et al (2010). Effects Of 5 Weeks Training At The Same Time Of Day On The Diunal Variations Of Maximal Muscle Performance. J Strength Cond Res. 24(1): 23-29. DOI: 10.1519/JSC.0b013e3181b295d6

Knaier R, Qian J, Roth R et al (2022). Diurnal Variation In Maximum Endurance And Maaximum Strenhth Performance : A Systematic Review And Meta-Analysis. M Sci Sports Ex. 54(1): 169-180. DOI: 10.1249/MSS.0000000000002773

Are We Losing Talented Young Athletes?

Picture by Richard Seow from Flickr

I came across a really interesting article (Abbott et al, 2020) this week measuring adolescent maturation with respect to sports. 

Our Singapore national school sports competitions use chronological age to categorize adolescent athletes. Australia does the same when it comes to their age group swimming competitions.

The researchers in the paper use a handful of physiological measurements to come up with an estimate of an adolescent's relative age. So, for two 13 year olds born exactly on the same day, one of them can be an early maturer with a relative age of say 13 years and 7 months. The other adolescent can be a late maturer with a relative age of 12 years and one month. They both have the same birthdate, however, in practice one has a 18 months maturity advantage over the other.

The table in the picture above shows the researchers' maturation measure applied to age group swimmers in Australia competing in the 100 m freestyle. You can see that all the swimmers at the top end of this Australian age group are those in the "early" or "early-normal" categories. They are the faster swimmers.

Look at the "late" maturers column, it's a whole long line of zeros. If you look at it from another perspective, it also means that Australia is losing 50 percent of their talent pool. These swimmers probably started swimming with the rest of their age cohort, but by age 13, they probably all became disillusioned and dropped out. So where did all these slowly maturing kids go? Did they all decide to play computer games instead? Hopefully, they found another sport to participate in.

To find their next generation of elite swimmers, Australia is using a high stakes, winner takes all competitive swim competitions. The effect of those competitions was to chase away half the cohort of young swimmers away from swimming.

Now, if we relate this to Singapore's own school sports scene, does this mean that the Singapore Sports School and other schools' Direct School Admission (DSA) selection criteria is also slightly flawed? Perhaps that can explain why many of these 'talented' kids who are early maturers (at 13 years old when they go to Secondary school) don't carry on competing and drop out. 

If you read my earlier post, it it reasonable to say that some of these early maturing athletes in the Sports School or DSA programs would have exceled in any physical screening tests. Just like my classmate in that post who reached puberty and had his growth spurt earlier than us in Primary school. He was physically superior to everyone else. That's how he won all his track events earlier. When the rest of us "caught up" when we hit puberty, he didn't have that advantage anymore.

Having been raised on victories from young, they may not comprehend or accept defeat. Early victories may have paved the way for defeat and giving up eventually.

Please take note that I am not criticising the Singapore Sports School or the DSA programs currently in place. I am just suggesting that our local childhood talent selection programs, on closer examination, are not as meritocratic as they may seem.

A child/ adolescent who is a late maturer may not necessarily be not talented in sports. It may be a lack of motivation. No child or adolescent will persist or strive in an athletic activity if they do not feel they are competitive with their peers.

My wishes for these national schools competitions are that that they can provide opportunities for students to experience joy (and of course heart break) from exercise and competition. To lay down life-long habits of physical activity. And finally to provide those with ability for futher higher level competiton to represent their country. 

Reference

Abbott S, Hogan C, Castiglioni MT et al (2020). Maturity- related Developmental Inequalities In Age-group Swimming: The Testing of 'Mat-CAPs' For Their Removal. J Sci Med Sp. 24(4): 397-404. DOI: 10.1016/jsams.2020.10.003

Are Sports Drinks Overhyped?

My patient was asking me what I fuel myself with for my weekly Saturday bike rides. He knows I usually ride between 70-90 km. He was shocked when I said that I only bring a banana and a bottle of water with a slice of lemon for taste. 

Perhaps he had been influenced by social media and advertisements, and felt that hydrogels, superstarch, theanine, isotonics and even coconut water packed with potassium were better for absorbing carbohydrates into our system while exercising.

SuperStarch?

Perhaps some of the latest choices mentioned earlier may give an extremely small edge. Do they perk you up in the morning, help you metabolize energy, increase your focus and 'protect' your body as they claim? Especially since none of them are solidly backed by research. Will you go and order the latest offerings? 

I've written before that sports drinks definitely cannot replace your sodium levels during exercise. What it can definitely do is to provide you with some carbohydrates for fuel during prolonged (longer than 90 minutes) exercise to sustain your level of performance.

Results suggest that sports drinks can fuel you to maintain athletic performance. In the article referenced below, the authors wanted to know if a pre-exercise meal affects sports drink effectiveness. The subjects (cyclists) rode 105 minutes at lactate threshold followed by a 10 km time trial under 4 conditions. No breakfast before the ride with a placebo sports drink. No breakfast with a real sports drink. Breakfast with a placebo sports drink and breakfast with a real sports drink.

The breakfast the riders had were consumed 3 hours before the exercise. It had 824 calories, consisting of two thirds conbohydrates. The real sports drink had 8 percent maltodextrin (works like glucose but has no taste) while the placebo was just artificially sweetened. The sports drink was consumed every 15 minutes during the first 105 minutes ride and halfway mark of the 10 km time trial. 

Those who had the real sports drink with breakfast managed 198 watts in the time trial, those without 197 watts, not much difference. Strangely enough the results did not give any boost to the cyclists who fasted (no breakfast). I would have thought that the sports drink would help those who did not eat breakfast, ride better. Other studies did find a difference. Using the real sports drink helped with or without breakfast. 

There was definitely a negative effect for those who skipped breakfast without the real sports drink. With breakfast but no sports drink the cyclists managed 173 watts, with no breakfast, no sports drink it was 154 watts. They also had the highest rate of perceived exertion.

Note that at the start of the time trial, those who had breakfast with placebo drinks kept up with those with breakfast and real sports drink. As the time trial progressed and fuel stores were used up, those without the real sports drink fell farther and farther behind since their placebo drink failed to fuel them. 

This study shows that consuming carbohydrates during prolonged exercise definitely makes a difference. What I liked about the study was that the subjects did not know if their sports drink was real or placebo. The time trial started only after 105 mins, long enough for carbohydrate stores to be depleted. There was also no funding (from the sports drinks industry) for this study, so less chance of any bias.

If you are out racing or training for a few hours or more, commercial sports drinks aren't the only option. Neither is hydrogel, superstarch or any of the latest offers. Many sports drink companies may advertise their specialized formulations, but the 3 basic ingredients needed are water, sugar and salt. Beyond these 3 ingredients the science gets a lot weaker. 

Many triathletes drink flat Coke (see picture below) in the Ironman events and eat bananas or dried figs. I'll usually just have a banana, dried raisins or dates. Just make sure you have something to suit your palate. Oh! And remember not to skip breakfast.

Reference

Leari SK, Ghiarone T, Silva-Cavalcante MD et al (2019). Cycling Time Trial Performance Is Improved By Carbohydrate Ingestion During Exercise Regardless Of A Fed Or Fasted State. Scan J Med Sci Sp. 29(5): 651-662 DOI: 10.1111/sms.13393.

You can the dark Coke stains on the front Mark Allen's top after beating Dave Scott after 6 attempts and finally winning at the 1989 Hawaii Ironman. 

*Picture taken from my book Ironwar by Mark Fitzgerald, Velopress 201.