wǒ jīntiān zuò lìliàngxùnliàn.

The sentence follows a very common Chinese pattern:

Subject + Time + Verb + Object

So here it is:

• 我 = I
• 今天 = today
• 做 = do
• 力量训练 = strength training

So literally, it is:

I + today + do + strength training

This is very natural in Mandarin. Time words often come before the verb.

In Mandarin, time expressions usually come before the main verb.

So:

• 我今天做力量训练。 = I do strength training today.

This is more natural than putting 今天 at the end.

A good rule to remember is:

• Subject + time + verb + object

Examples:

• 我今天上班。 = I’m working today.
• 他明天去北京。 = He is going to Beijing tomorrow.

Yes, absolutely.

Both are natural:

• 我今天做力量训练。
• 今天我做力量训练。

The difference is mainly about emphasis:

• 我今天做力量训练。 = neutral, straightforward
• 今天我做力量训练。 = slightly emphasizes today

For example, if you are contrasting today with other days, 今天我... can sound especially natural.

做 usually means to do or to engage in something.

In this sentence, 做力量训练 means to do strength training.

Chinese often uses 做 with activities, especially when English would also use do:

• 做运动 = do exercise
• 做训练 = do training
• 做瑜伽 = do yoga

So 做力量训练 is a very natural way to say do strength training.

力量训练 is a compound noun meaning strength training.

It breaks down like this:

• 力量 = strength
• 训练 = training

Together:

• 力量训练 = strength training

So in the sentence, 做力量训练 means to do strength training.

Mandarin usually does not mark tense the way English does.

So 做 by itself can often mean:

• do
• am doing
• will do

The exact meaning depends on context.

Because the sentence includes 今天 (today), it can naturally mean something like:

• I’m doing strength training today.
• I do strength training today.
• I will do strength training today.

In real conversation, context usually makes it clear.

If you want to make the action clearly completed, you can say:

• 我今天做了力量训练。 = I did strength training today.

By itself, it usually means sometime today, not necessarily right now.

So 我今天做力量训练。 is more like:

• I’m doing strength training today.
• I do strength training today.

If you want to say right now, you would usually add something like:

• 我今天在做力量训练。
• 我现在在做力量训练。 = I’m doing strength training right now.

If you want to say you already finished, use 了:

• 我今天做了力量训练。

Yes, if the subject is already clear from context.

For example, if someone asks what you’re doing today, you can simply say:

• 今天做力量训练。

Chinese often drops subjects when they are obvious.

But if you are giving a full sentence on its own, especially for learning purposes, keeping 我 is perfectly good.

The pinyin is:

lìliàng xùnliàn

A few tips:

• 力 = fourth tone
• 量 = fourth tone
• 训 = fourth tone
• 练 = fourth tone

So there are several fourth tones in a row. In natural speech, native speakers usually do not make every fourth tone equally strong and dramatic. The first of two fourth tones is often a bit shorter, while the second falls more fully.

So 力量训练 should sound smooth, not like four separate heavy drops.

Also note:

• 训练 is pronounced xùnliàn
• not xùnxī or anything similar

No, not in this sentence.

力量训练 is being treated as an activity, so you can just say:

• 做力量训练

You only need a measure word if you want to count sessions or times, for example:

• 做一次力量训练 = do one strength-training session
• 做两次力量训练 = do strength training twice / do two sessions

So the original sentence is complete and natural without one.

Yes. A few common alternatives are:

• 我今天做力量训练。 = I’m doing strength training today.
• 我今天练力量。 = I’m training strength today.
  This sounds a bit more casual.
• 我今天去健身房做力量训练。 = I’m going to the gym to do strength training today.
• 我今天做了力量训练。 = I did strength training today.

Your original sentence is correct and natural, especially in standard, clear Mandarin.