diff --git a/CHANGELOG.md b/CHANGELOG.md
index 1cc78b8d..2df67a5a 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,6 +6,7 @@
 - Faster runtime-error detection: single `case` glob instead of 23-iteration loop in `detect_runtime_error` (#668)
 - Hot-path coverage flag now cached in `_BASHUNIT_COVERAGE_ON`, removing a function dispatch per call (#664)
 - Parallel runner blocks on `wait -n` on Bash 4.3+ instead of polling `jobs -r`, removing sleep-induced slot-release latency (#667)
+- Hot-path result helpers (`extract_encoded_field`, `extract_subshell_type`, `format_subshell_output`, `compute_total_assertions`) use outvar pattern, dropping a fork per call per test (#662)
 
 ## [0.36.0](https://github.com/TypedDevs/bashunit/compare/0.35.0...0.36.0) - 2026-05-07
 
diff --git a/src/runner.sh b/src/runner.sh
index 7a266141..dc071561 100755
--- a/src/runner.sh
+++ b/src/runner.sh
@@ -57,48 +57,71 @@ function bashunit::runner::apply_interpolated_title() {
   printf '%s' "$interpolated"
 }
 
+# All four helpers below use the outvar pattern (first argument is the name of
+# the variable to assign into) so callers can avoid the per-test $(...) subshell
+# capture in the hot path. Internal locals use a `__bu_` prefix to avoid name
+# collisions with caller variables passed by name.
+
+# Writes the value of an encoded field (##KEY=value##) into the named outvar.
+# Arguments: $1 outvar name, $2 test_execution_result, $3 key
 function bashunit::runner::extract_encoded_field() {
-  local test_execution_result=$1
-  local key=$2
-  local marker="##${key}="
-  case "$test_execution_result" in
-  *"$marker"*)
-    local rest="${test_execution_result#*"$marker"}"
-    printf '%s' "${rest%%##*}"
+  local __bu_out=$1
+  local __bu_in=$2
+  local __bu_key=$3
+  local __bu_marker="##${__bu_key}="
+  local __bu_val=""
+  case "$__bu_in" in
+  *"$__bu_marker"*)
+    local __bu_rest="${__bu_in#*"$__bu_marker"}"
+    __bu_val="${__bu_rest%%##*}"
     ;;
-  *) printf '' ;;
   esac
+  eval "$__bu_out=\$__bu_val"
 }
 
+# Writes the sum of all ASSERTIONS_* counters into the named outvar.
+# Arguments: $1 outvar name, $2 test_execution_result
 function bashunit::runner::compute_total_assertions() {
-  local test_execution_result=$1
-  local failed passed skipped incomplete snapshot
-  failed="${test_execution_result##*##ASSERTIONS_FAILED=}"
-  failed="${failed%%##*}"
-  passed="${test_execution_result##*##ASSERTIONS_PASSED=}"
-  passed="${passed%%##*}"
-  skipped="${test_execution_result##*##ASSERTIONS_SKIPPED=}"
-  skipped="${skipped%%##*}"
-  incomplete="${test_execution_result##*##ASSERTIONS_INCOMPLETE=}"
-  incomplete="${incomplete%%##*}"
-  snapshot="${test_execution_result##*##ASSERTIONS_SNAPSHOT=}"
-  snapshot="${snapshot%%##*}"
-  printf '%d' "$((${failed:-0} + ${passed:-0} + ${skipped:-0} + ${incomplete:-0} + ${snapshot:-0}))"
+  local __bu_out=$1
+  local __bu_in=$2
+  local __bu_failed __bu_passed __bu_skipped __bu_incomplete __bu_snapshot
+  __bu_failed="${__bu_in##*##ASSERTIONS_FAILED=}"
+  __bu_failed="${__bu_failed%%##*}"
+  __bu_passed="${__bu_in##*##ASSERTIONS_PASSED=}"
+  __bu_passed="${__bu_passed%%##*}"
+  __bu_skipped="${__bu_in##*##ASSERTIONS_SKIPPED=}"
+  __bu_skipped="${__bu_skipped%%##*}"
+  __bu_incomplete="${__bu_in##*##ASSERTIONS_INCOMPLETE=}"
+  __bu_incomplete="${__bu_incomplete%%##*}"
+  __bu_snapshot="${__bu_in##*##ASSERTIONS_SNAPSHOT=}"
+  __bu_snapshot="${__bu_snapshot%%##*}"
+  local __bu_val
+  __bu_val=$((${__bu_failed:-0} + ${__bu_passed:-0} + ${__bu_skipped:-0}))
+  __bu_val=$((__bu_val + ${__bu_incomplete:-0} + ${__bu_snapshot:-0}))
+  eval "$__bu_out=\$__bu_val"
 }
 
+# Writes the subshell type marker (text inside leading [...]) into the named outvar.
+# Arguments: $1 outvar name, $2 subshell_output
 function bashunit::runner::extract_subshell_type() {
-  local subshell_output=$1
-  local type="${subshell_output%%]*}"
-  printf '%s' "${type#[}"
+  local __bu_out=$1
+  local __bu_in=$2
+  local __bu_val="${__bu_in%%]*}"
+  __bu_val="${__bu_val#[}"
+  eval "$__bu_out=\$__bu_val"
 }
 
+# Writes the subshell output (minus the leading [type] marker, with embedded
+# status markers replaced by newlines) into the named outvar.
+# Arguments: $1 outvar name, $2 subshell_output
 function bashunit::runner::format_subshell_output() {
-  local subshell_output=$1
-  local line="${subshell_output#*]}"
-  line=${line//\[failed\]/$'\n'}
-  line=${line//\[skipped\]/$'\n'}
-  line=${line//\[incomplete\]/$'\n'}
-  printf '%s' "$line"
+  local __bu_out=$1
+  local __bu_in=$2
+  local __bu_val="${__bu_in#*]}"
+  __bu_val=${__bu_val//\[failed\]/$'\n'}
+  __bu_val=${__bu_val//\[skipped\]/$'\n'}
+  __bu_val=${__bu_val//\[incomplete\]/$'\n'}
+  eval "$__bu_out=\$__bu_val"
 }
 
 function bashunit::runner::detect_runtime_error() {
@@ -815,8 +838,8 @@ function bashunit::runner::run_test() {
 
   if [ -n "$subshell_output" ]; then
     local type
-    type=$(bashunit::runner::extract_subshell_type "$subshell_output")
-    subshell_output=$(bashunit::runner::format_subshell_output "$subshell_output")
+    bashunit::runner::extract_subshell_type type "$subshell_output"
+    bashunit::runner::format_subshell_output subshell_output "$subshell_output"
     if ! bashunit::env::is_failures_only_enabled; then
       bashunit::state::print_line "$type" "$subshell_output"
     fi
@@ -832,12 +855,12 @@ function bashunit::runner::run_test() {
   local test_exit_code="$_BASHUNIT_TEST_EXIT_CODE"
 
   local total_assertions
-  total_assertions=$(bashunit::runner::compute_total_assertions "$test_execution_result")
+  bashunit::runner::compute_total_assertions total_assertions "$test_execution_result"
 
   local encoded_test_title hook_failure encoded_hook_message
-  encoded_test_title=$(bashunit::runner::extract_encoded_field "$test_execution_result" "TEST_TITLE")
-  hook_failure=$(bashunit::runner::extract_encoded_field "$test_execution_result" "TEST_HOOK_FAILURE")
-  encoded_hook_message=$(bashunit::runner::extract_encoded_field "$test_execution_result" "TEST_HOOK_MESSAGE")
+  bashunit::runner::extract_encoded_field encoded_test_title "$test_execution_result" "TEST_TITLE"
+  bashunit::runner::extract_encoded_field hook_failure "$test_execution_result" "TEST_HOOK_FAILURE"
+  bashunit::runner::extract_encoded_field encoded_hook_message "$test_execution_result" "TEST_HOOK_MESSAGE"
 
   local test_title=""
   [ -n "$encoded_test_title" ] && test_title="$(bashunit::helper::decode_base64 "$encoded_test_title")"
diff --git a/tests/unit/runner_test.sh b/tests/unit/runner_test.sh
index 0e8745d9..5c1e3af0 100644
--- a/tests/unit/runner_test.sh
+++ b/tests/unit/runner_test.sh
@@ -127,3 +127,49 @@ function test_detect_runtime_error_matches_unexpected_eof() {
 
   assert_same "line 5: unexpected EOF while looking for matching" "$actual"
 }
+
+function test_extract_encoded_field_writes_value_to_outvar() {
+  local out=""
+  bashunit::runner::extract_encoded_field out \
+    "preamble##TEST_TITLE=hello world##ASSERTIONS_PASSED=1" "TEST_TITLE"
+
+  assert_same "hello world" "$out"
+}
+
+function test_extract_encoded_field_writes_empty_when_key_missing() {
+  local out="prior"
+  bashunit::runner::extract_encoded_field out "##ASSERTIONS_PASSED=1" "TEST_TITLE"
+
+  assert_empty "$out"
+}
+
+function test_compute_total_assertions_sums_into_outvar() {
+  local out=""
+  bashunit::runner::compute_total_assertions out \
+    "##ASSERTIONS_FAILED=1##ASSERTIONS_PASSED=2##ASSERTIONS_SKIPPED=3##ASSERTIONS_INCOMPLETE=4##ASSERTIONS_SNAPSHOT=5"
+
+  assert_same "15" "$out"
+}
+
+function test_compute_total_assertions_treats_missing_counters_as_zero() {
+  local out=""
+  bashunit::runner::compute_total_assertions out "##ASSERTIONS_PASSED=2"
+
+  assert_same "2" "$out"
+}
+
+function test_extract_subshell_type_strips_brackets_into_outvar() {
+  local out=""
+  bashunit::runner::extract_subshell_type out "[failed] something happened"
+
+  assert_same "failed" "$out"
+}
+
+function test_format_subshell_output_strips_type_and_expands_markers() {
+  local out=""
+  bashunit::runner::format_subshell_output out "[failed] line1[skipped]line2[incomplete]line3"
+
+  local expected
+  expected=$' line1\nline2\nline3'
+  assert_same "$expected" "$out"
+}