Performance Sport Care - Douglas F. Cancel, DC

09/10/2026

If you've spent much time in a CrossFit gym, the three areas at the top of this infographic probably won't surprise you.

Shoulder. Low back. Knee.

What's more interesting is what the research says about who is more likely to get injured.

One of the clearest risk factors is having been injured before. Research has also found lower injury rates among athletes who train with coaching compared with those who train without it.

That changes how we think about returning to CrossFit after an injury.

Being able to get through everyday life without pain doesn't necessarily mean your shoulder is ready for high-volume overhead work. It doesn't mean your back is ready to pull from the floor under fatigue. And it doesn't mean your knee is ready for the volume and intensity you were handling before the injury.

That gap between feeling better and being prepared to train is where rehabilitation matters.

At Performance Sport Care, we work to identify what's driving the problem, restore the strength and capacity that have been lost, and progressively prepare athletes for the actual demands of their training.

We put together the infographic above from the CrossFit injury literature, and the full article takes a deeper look at what the research shows.

If a shoulder, back, or knee problem keeps returning every time you ramp training back up, schedule an evaluation. We'll help you figure out why.

09/08/2026

Ask who gets RED-S and most people will say female endurance athletes. The pooled data does not agree.

RED-S stands for Relative Energy Deficiency in Sport. It means not eating enough to cover what training costs, so the body draws against its own tissues for repair and growth.

Across 6,118 athletes in 46 studies, 44.2% of female athletes met the criteria. Among male athletes it was 49.4%.

Male athletes are screened for it far less, and there is a reason. The standard screening questionnaire cannot be used in men — about half its questions ask about menstrual periods. In female athletes there is an obvious early signal. In male athletes there is not, so it tends to be found late and often through bone.

In one group of 50 competitive male cyclists, 28% were not eating enough for their training and 44% had low bone density in the lower spine. These were trained, competitive athletes.

Awareness is the other half of the problem. In a separate group of 260 elite athletes, fewer than 10% had heard of the condition at all.

These are averages pooled across many sports, so individual teams and athletes will differ.

If you coach or parent a male athlete, this is worth two minutes.

09/07/2026

RED-S is usually math, not motivation.

The graphic makes a straightforward point: Relative Energy Deficiency in Sport is rarely driven by a desire to be lean. Training increases. Meals stay the same. The shortfall shows up later as stalled performance, lingering soreness, frequent illness, or a second stress injury.

In a screening cohort of 464 adolescent female athletes, 80% of those affected by low energy availability had no signs of disordered eating and no intention to lose weight — yet still demonstrated lower bone density than their peers.

Common questions:
"Does this only apply to athletes who are restricting?" → No. Most cases are not intentional. Training load simply rose while food intake remained unchanged.
"If the athlete is still performing well, isn't fueling adequate?" → No. Good performance does not guarantee enough residual energy for bone remodeling and tissue repair.

At Performance Sport Care in Walnut Creek, nutritional counseling is part of the clinical evaluation when an injury will not resolve. We examine training-load changes, meal timing, carbohydrate availability, sleep, and injury history so the body has energy left to rebuild.

Read the full post: performancesportcare.com/red-s-relative-energy-deficiency-in-sport/

If this cycle feels familiar, schedule an evaluation.

09/03/2026

Jumper's knee usually is not bad luck. It appears when training climbs faster than the tendon can build up to handle it.

A tendon adapts, but slowly. Training volume can double in a week; capacity cannot. Where those two lines cross is where the pain begins.

Here is the part that catches almost everyone. Pain and healing run on different clocks. Pain quiets down first, often within a few weeks. The tendon needs considerably longer to recover its strength. Stopping when it stops hurting is the most common reason this returns.

That is not a discipline problem. Pain is the only signal you can actually feel, and it goes quiet while the work is still unfinished.

What sets it off: a sudden jump in practice or jump volume, going straight back to full training after time off, heavy squats stacked on high jump volume, limited ankle flexibility, and not enough recovery between sessions.

What lowers the odds: build jump volume in steps rather than leaps, keep track of how many jumps are in a week, work on ankle flexibility, practise how you land, and keep going after the pain stops.

Coming back too fast is the most common reason it returns. Capacity has to be rebuilt before the load goes back on.

09/01/2026

If the same injury keeps coming back, you may be fighting with one hand tied behind your back.

Your body uses food for two jobs. Fuel for training is the loud one. Repair and growth — bone, tendon, hormones, immune function — is the quiet one.

When training demand rises and eating stays the same, the loud job wins. The body meets the demand in front of it and draws against its own tissues for the rest. Repair gets cut first, and nothing about it appears on a standard exam. Which is why care aimed at the sore spot can work and still not hold.

Across 6,118 athletes in 46 studies, nearly 45% were not eating enough for their training load. Most were not dieting. Training demand rose. Eating stayed the same. It is arithmetic, not poor motivation.

Not every recurring injury is this — load errors and incomplete rehabilitation are more common. But it belongs on the list.

If someone you know has been treated for the same injury more than once, share this with them.

08/28/2026

You rested it. You iced it. The brace helped for about two weeks. Then you walked 36 holes over a weekend and the pain came right back.

Rest can quiet irritated tissue. It does not change why that tissue was taking more load than it could handle. In golf, the place that hurts is not always the place that started the overload.

Every swing sends force from the ground through the hips and trunk before it reaches the club. When one link cannot rotate or stabilize enough, another link takes the extra work. A common pattern: limited rotation in the lead hip shifts demand onto the lumbar spine, which is built to bend far more than it is built to twist.

Walnut Creek golfers load that chain in different ways: walking Boundary Oak twice a week, or stacking shorter rounds at Diablo Hills and Rossmoor.

New article on why the same golf injury keeps returning, and what actually has to change:

You rested it. You iced it. You bought the brace, and it helped for about two weeks. Then the pain came right back.

08/27/2026

Not every sore knee is the same problem. Patellar tendinopathy, better known as jumper's knee, has a recognisable pattern.

Three findings point to it. Pinpoint tenderness at the bottom tip of the kneecap, felt with the knee straight and the thigh relaxed. Stiffness on standing up after sitting a while, which eases once you get moving. And pain on a slow single-leg squat with the heel raised.

There is usually little warmth or puffiness around the knee, and that detail helps separate it from other causes of front-of-knee pain.

It turns up most in volleyball, basketball, CrossFit and weightlifting, and in sprinters and jumpers. Two risk factors show up again and again: a sudden jump in training volume, and limited ankle flexibility.

These findings suggest a pattern rather than a diagnosis. An examination is what rules the alternatives in or out.

The reason to catch it early is simple. With proper management there is a real chance of healing. Ignored, it may not have that chance.

Share this with an athlete who has been calling it a sore knee for a while.

08/25/2026

When people hear that an athlete is not eating enough, they assume an eating disorder. Usually that is not what is happening.

Researchers screened 464 adolescent athletes. Thirty met the criteria. Of those thirty, 80% showed no signs of disordered eating and did not report wanting to lose weight. They still had lower bone density than their peers.

What happened instead is arithmetic. A season started, or a second sport was added, or a growth spurt arrived. Training demand rose and eating stayed the same. The body pays for training first and draws against its own tissues for everything else — bone, tendon, hormones, immune function.

What families tend to notice: performance has stalled, soreness lingers longer than it used to, illness becomes frequent, or a second stress injury appears.

One small study, all female, so other groups will differ. But the pattern holds.

Fall season starts soon. When training goes up, food intake should follow.

Share this with a parent heading into the season.

08/24/2026

We explain what happens to the neck in different car crash scenarios and how we help people that have sustained injury.

After a Walnut Creek crash, a normal X-ray does not mean you are uninjured. 60-minute evaluation, supervised rehab, a clear endpoint. (925) 945-1155.

08/19/2026

Rest alone doesn't fix shin splints. Here's what the evidence says actually works.

Shin splints (medial tibial stress syndrome) are common and easy to ignore, but can lead to stress fractures. Assessment and treatment in Walnut Creek from Douglas F. Cancel, D.C.