Can a Blood Test Really Help You Train Smarter and Feel Better?

When was the last time you had a blood test—not just to see if you’re sick, but to really understand what’s going on inside your body?

As a strength and conditioning coach, I’m all about helping you move better, get stronger, and feel more energized. But here’s the thing: if your body is missing key vitamins and minerals, no amount of training or clean eating will quite get you the results you want.

So, what’s really happening beneath the surface?

Let’s chat about why regular blood tests can be a total game-changer for your health and fitness journey.

Why Blood Tests Matter (Even If You “Feel Fine”)

Ever wonder if you could be low on Vitamin D, iron, or B12 and still manage to get through your day? The answer: absolutely. But those little imbalances? They quietly pile up. Over time, they can sap your energy, weaken your muscles, slow recovery, drag down your mood, and even increase your injury risk.

Would you keep driving your car with the “check engine” light on? Probably not.

So why ignore signs like poor sleep, constant soreness, or brain fog?

A simple blood test gives you clear info, so you can make smarter moves with your training, nutrition, and recovery.

My Own Experience with Ferritin

Being vegetarian, I’ve struggled with low ferritin—the protein that stores iron in your body. Once, my levels dropped dangerously low. I was getting cold sores all the time, felt wiped out, and my training just stalled.

I tried pushing through, but my energy was flat. It wasn’t until I got a blood test, discovered the issue, and received treatment (intravenous iron injections) that my energy and training results shot through the roof.

That’s the power of blood tests—they reveal what your body isn’t telling you. Ignoring symptoms won’t fix the problem, but knowing what’s up puts you in the driver’s seat.

What Should You Get Tested?

If you’re feeling tired, weak, or just “off,” here are some basic key markers to ask your doctor about:

• Vitamin D (25(OH)D): Crucial for bones, immunity, and muscle strength. Many Kiwis are low during winter. Deficiency signs: low mood, frequent colds.

  
  

• Vitamin B12: Needed for energy, red blood cells, and nerves. Vegetarians, vegans, and people with gut issues are at risk. Deficiency signs: fatigue, tingling hands/feet.

  
  

• Iron & Ferritin: Iron carries oxygen through your blood. Low iron = low stamina and slow recovery. Common in women, runners, and heavy exercisers.

  
  

• Magnesium & Zinc: Help with muscle function, sleep, and stress. Deficiencies can cause cramps, irritability, and slow healing.

  
  

• Folate: Works with B12 for blood and brain health. Low levels may cause fatigue and mouth sores.

  
  

• Thyroid Function (TSH, Free T3, Free T4): Controls metabolism and energy. If you feel sluggish or slow to recover, thyroid tests can help.

What About Heart and Metabolic Health?

Even if you’re not “overweight,” it’s smart to watch these markers:

• LDL & HDL Cholesterol: LDL is the “bad” kind that can raise heart risks; HDL is the “good” kind that helps clear LDL. Exercise and strength training improve both.

  
  

• Triglycerides: These fats can hint at metabolic trouble. Exercise and cutting sugar/alcohol help lower them.

  
  

• HbA1c: Shows your average blood sugar over 2–3 months. High levels suggest insulin resistance. Strength training and healthy eating can reverse it.

  
  

• Liver Enzymes (ALT, AST, GGT, ALP): Your liver detoxes, digests fat, and regulates hormones. Elevated levels could mean fatty liver or other issues.

What Happens When You’re Deficient?

Your body is good at adapting—sometimes too good. You might blame feeling tired or slow on getting older or being busy, but it’s often:

• Low iron = poor stamina

• Low Vitamin D = weak bones and immunity

• Low B12 = brain fog and sluggishness

• Thyroid issues = slow metabolism and low energy

• Poor liver health = hormone imbalances

• High blood sugar = energy crashes

Knowing these numbers isn’t about chasing perfection. It’s about being aware and taking control.

What’s Next?

• Chat with your doctor about your results. They’ll help interpret them properly and order more tests as needed.

• Work with a coach (like me!) to tweak your training, nutrition, and recovery for what your body needs.

• Retest every 6 months to see how you’re tracking.

Your Health, Your Responsibility

We train hard to get stronger. But what if your body’s missing the fuel or nutrients it needs to perform?

Blood tests aren’t scary—they’re feedback. If you’re serious about strength, mobility, and longevity, start by knowing what’s happening inside.

Ready to Take the First Step?

Reach out anytime. Let’s chat about where you’re at—inside and out. At LifeForce, we help you build strength for life, starting with understanding your body.

References:

• New Zealand Ministry of Health – Vitamin D and Bone Health

• NIH Office of Dietary Supplements – B12, Iron, Vitamin D Fact Sheets

• Harvard Health – Why Triglycerides Matter

• PubMed ID: 22838236 – The Role of Vitamin D in Musculoskeletal Health

• British Journal of Sports Medicine – Exercise and HDL Improvement