Is Hyrox Just A Fad?

ST 240824

Hyrox is the newest brand of fitness trend currently sweeping Singapore and the world, it seems.

I do not have an Instagram account, but my wife and colleagues tell me that their IG feed had been flooded with friends dripping with sweat as they did lunges with 24kg sandbags, pushed 152kg sleds (pictured below), did burpee broad jumps etc interspersed with 1 km runs after Singapore hosted a race on 29/6/24. Our local paper, The Straits Times, also featured an article in today's (240824) paper on page A16 (pictured above).

Picture by Kenneth Lee from CNA

Hyrox cofounder and CEO Christian Toetzke wanted to create a sport with broader appeal that could bring mass participation to the gym and running space. He partnered Moritz Furste, previous Olympic gold medalist in field hockey to start their version of exercise. The special 'ingredient' is its mix of 8 movements requiring strength, power and endurance which requires you to push, pull, run, carry and throw. Exercises that could be assessed quickly by officials on the course were chosen since the idea was to hold events with large waves of competitors.

The exercises need to be relatively safe to do under fatigue and mustn't be more difficult for women than men. Hence, box jumps were taken out (for safety) and monkey bars too (more difficult for women). And so, Hyrox was 'born' in 2017 with 8 exercises and a total of 8 km of running.

The first ever Hyrox event was held in Germany with 650 participants in November 2017. Nearly 7 years later, Hyrox is on course to host 45 events for 425,000 participants in 5 continents this year (according to the company's statistics). Singapore's event on June 29th this year drew 6,500 participants, up from 3,500 last October. Singapore will be hosting another event next week on 1/9/24. More than 70 percent of the 6,500 participants in Singapore were millennials.

My wife who goes to UBX at Holland Village tells me that it helps that participants are doing the same exercises together. That strong community element definitely helps when the chips are down and helps with training adherence. The friendships made provide a sense of belonging especially for some people who have never participated in team sports before so this gives them a chance to experience camaraderie and accountability. For Hyrox, this sense of community is global since the race follows an identical format anywhere it is organized.

Gym owners and others in the fitness industry may feel all too familar with the hype around Hyrox after previous flavors of the month have come and gone. Perhaps some gym owners are wary after a recent spate of gym closures although the Hyrox Singapore organizer said that its standardized and accessible nature sets it apart.

I have not taken part in any Hyrox event, but I have done all the different exercises before, albeit not all at once. I will say that Hyrox will definitely help strength and endurance. Unlike the higher intensity CrossFit programmes which can be technically difficult for beginners and thus sets a higher bar for entry, Hyrox fits well in the group exercise spectrum. It also allows one to gauge your own progress.

Critics (not me) have mocked such fitness events/ trends and wondered why anyone would pay to do exercises that could be performed elsewhere for free. One of my patients said with humour that he paid almost $200 to 'torture' himself with friends. Some patients that I asked also said they started because of a 'mid-life' crisis.

One can call Hyrox a fad especially if they do not see the appeal. I am just happy people are getting off their couches and desks to start any form of physical activity to improve their health. Especially when Singapore's young adults' diets and physical activities in Singapore did not comply with international health guidelines (Leu et al, 2023).

81.8 percent of the surveyed participants did not meet World Health Organization requirements of at least 150 minutes of moderate intensity aerobic exercise or 75 minutes of vigorous intensity exercise and muscle strengthening exercises at least twice a week. 

Most of those surveyed said their exercises were walking to public transport stations and while looking for food. One subject even said that the weekend is the only time to like just "collapse".

Hyrox is definitely trendy and seems glamorous now that people love to post about it on social media, which is also contributing to its popularity. I am just glad Singaporeans are more active in whatever form of exercise they choose. Plus, if they overdo it and get injured they can come see us in our clinics.

Reference

Leu J, Rebello SA, Sargent GM et al (2023). Hard Work, Long Hours, And Singaporean Young Adults' Health - A Qualitative Study. Frontiers Pub Health. Vol 11, 12th June. DOI: 10.3389/fpubh.2023.1082581.

May The (Knee) Forces be With You

Picture from Hart et al, 2022

We were discussing the knee joint in our clinic this past week. Meaning ALL the conditions that can cause pain in the knee. Patellofemoral joint pain, patella tendinopathy, MCL, ACL injuries, fat pad irritation, torn meniscus etc. 

In order to understand knee joint injuries, we need to know what can increase load or amplify forces in the knee joint. An increase in joint forces can increase symptoms when one has patellofemoral pain (PFP) so it will be most helpful to know what activities may influence patellofemoral joint reaction forces (PFJRF).

Picture from Dr JT Andrish

So happened that I came across an article explaining how PFJRF compares across different activities and interventions.

intercondylar notch

PFJRF is created by tension (or forces) in the quadriceps and patella tendon which moves the patella into the intercondylar (pictured above) surface (of the femur). It can increase due to greater quadriceps muscle force or when there is an increase in knee flexion (or knee bending).

The article (systematic review) examined PFJFR in daily activities, exercises, interventions (treatment). It also compares healthy individuals to those with PFP or osteoarthritis (OA).

A total of 71 articles were included in the systematic review. Approximate PFJRF for healthy individuals during various activities are pictured below where BW = body weight. 

Knee joint forces in healthy individuals

As you can see, activities that involve greater knee flexion or greater external load resulted in higher PFJRF. For example a deep squat with a heavy weight.

An increase in knee flexion can increase the contact area (in the intercondylar area) and may therefore reduce patellofemoral contact pressure. The authors felt this would be the case in a knee that is "normally aligned". However, certain movements during loading such as increased hip adduction (pictured below) and/ or internal rotation may reduce contact area and increase contact pressure.

Increase in hip adduction in picture A

The authors reported that there were no discernible differences in peak PFJRF during daily activities between healthy individuals and those with PFP/ OA.

There are 3 options if you have knee pain and we need to reduce PFJRF. Reduce knee flexion/ bending during loading. Reduce external load. Reduce hip adduction/ internal rotation during loading.

So if you are weight training by doing a squat and your knee hurts. You can squat less (70-80 degrees) and / or using a lighter weight. Preferably with less hip adduction too. 

In running we can apply this by increasing step rate/ cadence to reduce patellofemoral load. Smaller, quicker steps reduces knee flexion and hip adduction during the stance phase of running. Or better still make your gluteus medius, hamstrings and calf muscle a lot stronger.

Note that the goal is to reduce load only when symptoms are present and the knee is irritated. You can gradually increase load again when able. For other clinicians and physiotherapists reading this, a progressive approach is needed and utimately it will be your patient symptoms and goals that will guide you.

Do note that the exact link between PFJRF and knee pain is complex and the lack of difference between those healthy inviduals without knee pain and those with PFP/ OA draws attention to this. 

The authors also mentioned that when articular cartilage is underloaded (not enough load), it may be an issue too. 

Reference

Hart HF, Patterson BE, Crossley KM et al (2022). May The Force Be With You: Understanding How Patellofemoral Joint Reaction Force Compares Across Different Activities And Physical Interventions- A Systematic Review And Meta-Analysis. BJSM. 56: 521-530. DOI: 10.1136/bjsports-2021-104686

Bioelectrical Impedance To Measure Body Fat?

BIA from Weightology

Last week, my helper's cousin asked me for suggestions with regards to measuring her body fat levels. Her cousin was about to sign up with a personal trainer  and he wanted to measure her body fat levels before they started. Of course that came with a cost before the training even started.

Picture from Bodybuilding Wizard 

I told my helper the most accurate method would be hydrostatic underwater weighing (or underwater weighing) which was very dificult to do (pictured above). I only did it as a physiotherapy student while doing the exercise physiology module in year 1. Next best was using callipers to measure the sum of 7 skinfolds (pictured below).

However, my helper said the trainer suggested using bioelectrical impedance analysis (BIA) to measure her cousin's body fat levels.

Bioelectrical impedance is a popular way to measure body fat levels. It is also practical  as it takes a relatively short analysis time. It is not invasive at all and it is available commercially at an affordable cost.

BIA measures body composition based on the rate at which an electric currrent travels through your body. Body fat (adipose tissue) causes greater resistance (impedance) than lean mass (muscle) and slows the rate of electric current traveling through the body. Based on that rate and your height, gender and weight, your body fat levels, fat free mass etc are calculated.

However, BIA is not accurate at all for determining body fat levels. A recently (Aug 2024) published study showed that all 3 BIA devices tested significantly underestimated body fat levels.

28 firefighters were evaluated using 3 BIA devices. A multifrequency BIA hand-to-foot device, a single frequency BIA foot scale and a single frequency handheld BIA device. These were measured against dual x-ray absorptiometry (DEXA) for comparison (Jagim et al, 2024).

All 3 BIA devices significantly under measured body fat levels. Errors ranged between 4 to 5.5 percent when compared to the DEXA scans. Despite it's ease of use and practicability, BIA should not be used to assess body fat levels.

If you do or if your trainer insists on using BIA, bear in mind that they are not accurate, but you can still use them to track changes over time. 

Picture from Topendsports

I would suggest using the sum of 7 skinfolds if you want to track your body fat levels rather than BIA as it would be more accurate. The callipers are also not expensive. The following locations are commonly used. The abdomen, pectoral area, mid axilla, subscapular area, quadriceps, suprailiac area and the triceps.

There is more to health than your body fat percentage or weight. These measurements are not a reflection of your general well being. 

Reference

Jagim AR, Luedke J, Erickson JL et al (2024). Validation Of Bioelectrical Impedance Devices For The Determination Of Body Fat Percentage In Firefighters. J Strength Cond Resc. 38(8): e448-453. DOI: JSC.0000000000004809. PMID: 39072665

Rock Climbing Injuries

Zi Yun competing

This is the second time rock climbing is contested at the Olympics since its debut at the 2021 Tokyo Olympics. For those who are not familiar, the three climbing disciplines include lead climbing, speed climbing, and bouldering. They are designed to challenge endurance, speed, and power, respectively.

Climbing gyms in Singapore has more than doubled since 2018, with nearly 40 climbing facilities now available. Contrary to popular belief, climbing is not only a physical sport that emphasizes on strength and technique, but also a test of mental tenacity. It demands problem solving skills, focus, composure, and resilience, whether you are a serious climber or just climbing recreationally. 

In a study on 436 climbers, 77.1% of the injuries affected the upper extremities, 17.7% lower extremities and 5.2% other body regions (Lutter et al, 2020). The most frequent injuries were finger pully injuries and finger tenosynovitis.

Bouldering has caused more acute injuries than rope-protected climbing. There are more knee injuries and shoulder dislocations. Young climbers were found to have more finger growth plate injuries.

There were also higher incidences of upper extremity injuries in bouldering (Kovářová et al, 2024). especially to the hands, fingers, wrists, and elbows.

Lead climbers had a broader range of injuries, including head, shoulder, and foot related injuries.

Traditional climbing (done outdoors in the natural environment) often results in more severe injuries involving long falls. Interestingly it's not personal characteristics (gender, age, weight or height) but human factors like concentration and fatigue that had significant impact on the number and severity of injuries  (Kovářová et al, 2024).

Just like other sports, if you increase your climbing intensity too quickly, have large muscle strength imbalances and rest insufficiently, you have a much higher chance of sustaining an injury. Many climbers do not rest or stop due to a fear of losing strength, leading to a decline in performance.

According to published studies, only 36% of injured climbers seek medical help. While some injuries were unavoidable, many were caused by the climbing culture of training with injuries and disregarding the need for recovery. This issue is compounded by insufficient knowledge on training and recovery, and ignorance. Many climbers also take injuries lightly and try to return to climbing too quickly.

However, you do not always have to completely stay off the wall or away from climbing related activities to recover. Modifications and other compensatory mechanisms can be done to your climbing session to achieve the same results. 

In order to attain climbing longevity, climbers need to be aware of the risks they are taking  and maintain appropriate recovery measures. If you are injured and unsure on how to go about your training, do come and see us for a thorough assessment, we will plan your treatment according to your concerns and goals. We promise to do our best to get you back strong on the wall as soon as possible.

*This week's post is written by Zi Yun (paper cloud), one of our new physiotherapists. She is a super rock climber. She wins most if not all the local rock climbing competitions and more. Having started climbing seven years ago, she has encountered many climbing related injuries and can defintely treat you if you are injured. Above pictures by Zi Yun.

References

Kovářová M, Pyszko P, and Kikalová K. (2024). Analyzing Injury Patterns in Climbing: A Comprehensive Study Of Risk factors. Sports, 12(2), 61. DOI: 10.3390/sports12020061

Lutter C, Tischer T, Hotfield T et al (2020). Current Trends In Sport Climbing Injuries After The Inclusion Into The Olympic Program. Analysis of 633 Injuries within the years 2017/18. Mus, Ligs Tendons J. 10(2), 201. DOI: 10.32098/mltj.02.2020.06